What is claimed is:

1. A method for programming a computer system including means for displaying images to control at least one of a virtual instrument and an instrument, the method comprising the steps of: displaying on the screen at least one first function-icon that references at least one first control means for controlling at least one first function; displaying on the screen at least one iteration-icon that references iteration control means for controlling multiple iterations of data flow; displaying on the screen at least one first input variable-icon that references at least one first input variable; displaying on the screen at least one first output variable-icon that references at least one first output variable and assembling on the screen a first acyclic data flow diagram including the at least one first function-icon and the at least one iteration-icon and the at least one first input variable-icon and the at least one first output variable-icon, such that the diagram displays a first procedure for producing at least one value for the at least one first output variable-icon from at least one value for the at least one first input variable-icon, and such that the at least one iteration-icon in the diagram indicates multiple iterations of the at least one first function in the course of the first procedure.

2. The method of claim 1 and further comprising the step of: assembling on the screen a first front panel including the at least one first input variable-icon and the at least one first output variable-icon.

3. The method of claim 2 and further comprising the step of: simultaneously displaying on the screen the first front panel and the first data flow diagram.

4. The method of claim 2 and further comprising the steps of: assigning at least one value for each at least one first input variable-icon; after assigning at least one value for each at least one first input variable-icon, producing at least one value for the at least one first output variable-icon from the at least one assigned value for each at least one first input variable-icon.

5. The method of claim 4 wherein said step of assigning includes the steps of: displaying said first front panel; setting the at least one first input variable-icon to display the at least one assigned value.

6. The method of claim 5 and further including the step of: displaying the at least one produced value in conjunction with the at least one first output variable-icon.

7. The method of claim 4 wherein said step of producing at least one value for the at least one first output variable-icon includes using said at least one first control means to control the first function.

8. The method of claim 7 wherein said step of producing at least one value for the at least one output variable-icon includes using the iteration control means to control multiple iterations of data flow to the at least one first control means.

9. The method of claim 1 wherein said step of assembling on the screen the first diagram includes: arranging on the screen the at least one first function-icon and the at least one iteration-icon such that in the first diagram the at least one first function-icon is displayed on the screen adjacent to the at least one iteration-icon.

10. The method of claim 1 wherein said step of assembling on the screen the first diagram includes: arranging on the screen the at least one first function-icon and the at least one iteration-icon such that in the first diagram the at least one first function-icon is displayed on the screen substantially inside the at least one iteration-icon.

11. The method of claim 1 and further comprising the step of: selecting the at least one first control means.

12. The method of claim 11 and further comprising the step of selecting the iteration control means.

13. The method of claim 12 wherein: said steps of selecting the at least one first control means and selecting the at least one iteration control means are performed automatically in the course of said steps of displaying on the screen the at least one first function-icon and displaying on the screen the at least one iteration-icon and assembling on the screen the first diagram.

14. The method of claims 12 or 13 wherein said first control means and said iteration control means are substantially implemented in software.

15. The method of claim 12 and further comprising the steps of: reserving first input variable space in memory of the computer system corresponding to the at least one first input variable-icon; and reserving first output variable space in memory of the computer system corresponding to the selected at least one first output variable-icon.

16. The method of claim 15 wherein: said step of reserving first input variable space is performed automatically in the course of said steps of displaying the at least one first input variable-icon and assembling on the screen the first diagram; and said step of reserving first output variable space is performed automatically in the course of said steps of displaying the at least one first output variable-icon and assembling on the screen the first diagram.

17. The method of claim 15 wherein said step of assembling on the screen the first diagram further includes the steps of displaying on the screen at least one first input arc between the at least one first input variable-icon and at least one of the at least one first function-icon and the at least one iteration-icon; and displaying on the screen at least one first output arc between the at least one first output variable-icon and at least one of the at least one first function-icon and the at least one iteration-icon; and further comprising the steps of: forming first input means for moving respective input values for the at least one first input variable between the at least one first input variable space and at least one of the at least one first control means and the iteration control means.

18. The method of claim 17 wherein: said step of forming first input means is performed automatically in the course of said step of displaying on the screen the at least one first input arc.

19. The method of claim 18 and further comprising the steps of: assigning at least one value for each at least one first input variable-icon; storing in the reserved first input variable space each at least one assigned value; after said steps of assigning and storing at least one value for each at least one first input variable-icon, moving each at least one value for the at least one first input variable-icon from the reserved first input variable space to at least one of the at least one first control means and the iteration control means using the first input means; after said steps of assigning and storing at least one value for each at least one first input variable-icon, producing at least one value for the at least one first output variable-icon using the at least one first control means to control the first function and using the iteration control means to control multiple iterations of data flow to the at least one first control means; and storing each produced value for the at least one first output variable-icon in the reserved first output variable space.

20. The method of claim 17 wherein:the at least one first control means and the iteration control means and the first input means are substantially implemented in software.

21. The method of claim 15 and further comprising the steps of: assigning at least one value for each at least one first input variable-icon; storing in the reserved first input variable space each at least one assigned value; after said steps of assigning and storing at least one value for each at least one first input variable-icon, producing at least one value for the at least one first output variable-icon; and storing each value for the at least one first output variable in the reserved first output variable space.

22. The method of claim 21 wherein: said step of storing each at least one assigned value is performed automatically in the course of said step of assigning.

23. The method of claim 1 wherein said step of assembling on the screen the first diagram further includes the steps of displaying at least one first input arc between the at least one first input variable-icon and at least one of the at least one first function-icon and the at least one iteration-icon and displaying on the screen at least one first output arc between the at least one first output variable-icon and at least one of the at least one first function-icon and the at least one iteration-icon.

24. A method for programming a computer system including display means for displaying images to control at least one of a virtual instrument and an instrument, the method comprising the steps of: displaying on the screen at least one first function-icon that references at least one first control means for controlling at least one first function; displaying on the screen at least one second function-icon that references at least one second control means for controlling at least one second function; displaying on the screen at least one conditional-icon that references conditional control means for controlling conditional branching of data flow; displaying on the screen at least one first input variable-icon that references at least one first input variable; displaying on the screen at least one first output variable-icon that references at least one first output variable; and assembling on the screen a first acyclic data flow diagram including the at least one first function-icon and the at least one second function-icon and the at least one conditional-icon and the at least one first input variable-icon and the at least one first output variable-icon, such that the diagram displays a first procedure for producing at least one value for the at least one first output variable-icon from at least one value for the at least one first input variable-icon, and such that the at least one conditional-icon in the diagram indicates a conditional branching of data flow to at least one of the at least one first function and the at least one second function in the course of the first procedure.

25. The method of claim 24 and further comprising the step of: assembling on the screen a first front panel including the at least one first input variable-icon and the at least one first output variable-icon.

26. The method of claim 25 and further comprising the steps of: assigning at least one value for each at least one first input variable-icon; after assigning at least one value for each at least one first input variable-icon, producing at least one value for the at least one first output variable-icon from the at least one assigned value for each at least one first input variable-icon.

27. The method of claim 26 wherein said step of assigning includes the steps of: displaying said first front panel; setting the at least one first input variable-icon to display the at least one assigned value.

28. The method of claim 27 and further including the step of: displaying the at least one produced value in conjunction with the at least one first output variable-icon.

29. The method of claim 26 wherein said step of producing at least one value for the at least one first output variable-icon includes at least one of: using said at least one first control means to control the first function; and using the at least one second control means to control the second function.

30. The method of claim 29 wherein said step of producing at least one value for the at least one output variable-icon includes using the conditional control means to control conditional branching data flow to at least one of the at least one first control means and the at least one second control means in the course of the first procedure.

31. The method of claim 25 and further comprising the step of: simultaneously displaying on the screen the first front panel and the first data flow diagram.

32. The method of claim 24 wherein said step of assembling on the screen the first diagram includes: arranging on the screen the at least one first function-icon and the at least one second function-icon and the at least one conditional-icon such that in the first diagram the at least one first function-icon is displayed on the screen adjacent to the at least one conditional-icon and the at least one second function-icon is displayed on the screen adjacent to the at least one conditional-icon.

33. The method of claim 24 wherein said step of assembling on the screen the first diagram includes: arranging on the screen the at least one first function-icon and the at least one second function-icon and the at least one conditional-icon such that in the first diagram the at least one first function-icon is displayed on the screen substantially inside the at least one conditional-icon and the at least one second function-icon is displayed on the screen substantially inside the at least one conditional-icon.

34. The method of claim 33 and further comprising the steps of: reserving first input variable space in memory of the computer system corresponding to the at least one fist input variable-icon; and reserving first output variable space in memory of the computer system corresponding to the at least one first output variable-icon.

35. The method of claim 34 wherein: said step of reserving first input variable space is performed automatically in the course of said steps of displaying the at least one first input variable-icon and assembling on the screen the first diagram; and said step of reserving first output variable space is performed automatically in the course of said steps of displaying the at least one first output variable-icon and assembling on the screen the first diagram.

36. The method of claim 34 and further comprising the steps of: assigning at least one value for each at least one first input variable-icon; storing in the reserved first input variable space each at least one assigned value; after said steps of assigning and storing at least one value for each at least one first input variable-icon, producing at least one value for the at least one first output variable-icon; and storing each produced value for the at least one first output variable in the reserved first output variable space.

37. The method of claim 36 wherein:said step of storing each at least one assigned value is performed automatically in the course of said step of assigning.

38. The method of claim 34 wherein said step of assembling on the screen the first diagram further includes the steps of displaying on the screen at least one first input arc between the at least one first input variable-icon and at least one of the at least one first function-icon and the at least one second function-icon and the at least one conditional-icon; and displaying on the screen at least one first output arc between the at least one first output variable-icon and at least one of the at least one first function-icon and the at least one second function-icon and the at least one conditional-icon; and further comprising the steps of: forming first input means for moving respective input values for the at least one first input variable between the at least one first input variable space and at least one of the at least one first control means and the at least one second control means and the conditional control means.

39. The method of claim 38 wherein: said step of forming first input means is performed automatically in the course of said step of displaying on the screen the at least one first input arc.

40. The method of claim 38 wherein: the at least one first control means and the at least one second control means and the conditional control means and the first input means are substantially implemented in software.

41. The method of claim 38 and further comprising the steps of: assigning at least one value for each at least one first input variable-icon; storing in the reserved first input variable space each at least one assigned value; after said steps of assigning and storing at least one value for each at least one first input variable-icon, moving each at least one value for the at least one first input variable-icon from the reserved first input variable space to at least one of the at least one first control means the at least one second control means and the conditional control means using the first input means; after said steps of assigning and storing at least one value for each at least one first input variable-icon, producing at least one value for the at least one first output variable-icon using at least one of a step using the at least one first control means to control the first function and a step of using the at least one second control means to control the second function; after said steps of assigning and storing at least one value for each at least one first input variable-icon, using the conditional control means to control conditional branching of data flow to at least one of the at least one first control means and the at least one second control means; and storing each produced value for the at least one first output variable-icon in the reserved first output variable space.

42. The method of claim 24 wherein said step of assembling on the screen the first diagram further includes the steps of displaying at least one first input arc between the at least one first input variable-icon and at least one of the at least one conditional-icon and the at least one first function-icon and the at least one second function-icon and displaying on the screen at least one first output arc between the at least one first output variable-icon and at least one of the at least one conditional-icon and the at least one first function-icon and the at least one second function-icon.

43. The method of claim 24 and further comprising the step of: selecting the at least one first control means and the at least one second control means.

44. The method of claim 43 and further comprising the step of selecting the conditional control means.

45. The method of claim 44 wherein: said steps of selecting the at least one first control means and selecting the at least one second control means and selecting the at least one conditional control means are performed automatically in the course of said steps of displaying on the screen the at least one first function-icon and displaying on the screen the at least one second function-icon and displaying on the screen the at least one conditional-icon and assembling on the screen the first diagram.

46. The method of claims 44 or 45 wherein said first control means and said second control means and said conditional control means are substantially implemented in software.

47. A method for programming a computer system including means for displaying images to control at least one of a virtual instrument and an instrument, the method comprising the steps of: displaying on the screen at least one first function-icon that references at least one first control means for controlling at least one first function; displaying on the screen at least one second function-icon that references at least one second control means for controlling at least one second function; displaying on the screen at least one sequence-icon that references sequence control means for controlling sequencing of data flow; displaying on the screen at least one first input variable-icon that references at least one first input variable; displaying on the screen at least one first output variable-icon that references at least one first output variable; and assembling on the screen a first acyclic data flow diagram including the at least one first function-icon and the at least one second function-icon and the at least one sequence-icon and the at least one first input variable-icon and the at least one first output variable-icon, such that the diagram displays a first procedure for producing at least one value for the at least one first output variable-icon from at least one value for the at least one first input variable-icon and such that the at least one sequence-icon in the diagram indicates a sequencing of the at least one first function and the at least one second function in the course of the first procedure.

48. The method of claim 47 and further comprising the step of: assembling on the screen a first front panel including the at least one first input variable-icon and the at least one first output variable-icon.

49. The method of claim 48 and further comprising the step of: simultaneously displaying on the screen the first front panel and the first data flow diagram.

50. The method of claim 48 and further comprising the steps of: assigning at least one value for each at least one first input variable-icon; after assigning at least one value for each at least one first input variable-icon, producing at least one value for the at least one first output variable-icon from the at least one value for each at least one first input variable-icon.

51. The method of claim 50 wherein said step of assigning includes the steps of: displaying said first front panel; setting the at least one first input variable-icon to display the at least one assigned value.

52. The method of claim 51 and further including the step of:displaying the at least one produced value in conjunction with the at least one first output variable-icon.

53. The method of claim 51 wherein said step of producing at least one value for the at least one first output variable-icon includes the steps of using the at least one first control means to control the first function and using the at least one second control means to control the second function.

54. The method of claim 53 wherein said step of producing at least one value for the at least one output variable-icon includes using the sequence control means to control sequencing of data flow to the at least one first control means and the second control means.

55. The method of claim 47 wherein said step of assembling on the screen the first diagram includes: arranging on the screen the at least one first function-icon and the at least one second function-icon and the at least one sequence-icon such that in the first diagram the at least one first function-icon is displayed on the screen adjacent to the at least one sequence-icon and the at least one second function-icon is displayed on the screen adjacent to the at least one sequence-icon.

56. The method of claim 47 wherein said step of assembling on the screen the first diagram includes: arranging on the screen the at least one first function-icon and the at least one second function-icon and the at least one sequence-icon such that in the first diagram the at least one first function-icon is displayed on the screen substantially inside the at least one sequence-icon and the at least one second function-icon is displayed on the screen substantially inside the at least one sequence-icon.

57. The method of claim 47 and further comprising the steps of: selecting the at least one first control means and the at least one second control means.

58. The method of claim 57 and further comprising the step of selecting the sequence control means.

59. The method of claim 58 wherein: said steps of selecting the at least one first control means and selecting the at least one second control means and selecting the at least one sequence control means are performed automatically in the course of said steps of displaying on the screen the at least one first function-icon and displaying on the screen the at least one second function-icon and displaying on the screen the at least one sequence-ion and assembling on the screen the first diagram.

60. The method of claims 58 or 59 wherein said first control means and said second control means and said sequence control means are substantially implemented in software.

61. The method of claim 58 and further comprising the steps of: reserving first input variable space in memory of the computer system corresponding to the selected at least one first input variable-icon; and reserving first output variable space in memory of the computer system corresponding to the selected at least one first output variable-icon.

62. The method of claim 61 wherein: said step of reserving first input variable space is performed automatically in the course of said steps of displaying the at least one first input variable-icon and assembling on the screen the first diagram; and said step of reserving first output variable space is performed automatically in the course of said steps of displaying the at least one first output variable-icon and assembling on the screen the first diagram.

63. The method of claim 62 wherein said step of assembling on the screen the first diagram further includes the steps of displaying on the screen at least one first input arc between the at least one first input variable-icon and at least one of the at least one first function-icon and the at least one second function-icon and the at least one sequence-icon; and displaying on the screen at least one first output arc between the at least one first output variable-icon and at least one of the at least one first function-icon and the at least one second function-icon and the at least one sequence-icon; and further comprising the steps of: forming first input means for moving respective input values for the at least one first input variable between the at least one first input variable space and at least one of the at least one first control means and the at least one second control means and the at least one sequence control means.

64. The method of claim 63 wherein: said step of forming first input means is performed automatically in the course of said step of displaying on the screen the at least one first input arc.

65. The method of claim 64 wherein: the at least one first control means and the at least one sequence control means and the first input means are substantially implemented in software.

66. The method of claim 63 and further comprising the steps of: assigning at least one value for each at least one first input variable-icon; storing in the reserved first input variable space each at least one assigned value; after said steps of assigning and storing at least one value for each at least one first input variable-icon, moving each at least one value for the at least one first input variable-icon from the reserved first input variable space to at least one of the at least one first control means and the at least one second control means and the sequence control means using the first input means; after said steps of assigning and storing at least one value for each at least one first input variable-icon, producing at least one value for the at least one first output variable-icon using the at least one first control means to control the first function and using the at least one second control means to control the second function and using the sequence control means to control sequencing of data flow to the at least one first control means and the at least one second control means; and storing each produced value for the at least one first output variable-icon in the reserved first output variable space.

67. The method of claim 61 and further comprising the steps of: assigning at least one value for each at least one first input variable-icon; storing in the reserved first input variable space each at least one assigned value; after said steps of assigning and storing at least one value for each at least one first input variable-icon, producing at least one value for the at least one first output variable-icon; and storing each produced value for the at least one first output variable in the reserved first output variable space.

68. The method of claim 67 wherein: said step of storing each at least one assigned value is performed automatically in the course of said step of assigning.

69. The method of claim 47 wherein said step of assembling on the screen the first diagram further includes the steps of displaying at least one first input arc between the at least one first input variable-icon and at least one of the at least one first function-icon and the at least one second function-icon and the at least one sequence-icon and displaying on the screen at least one first output arc between the at least one first output variable-icon and at least one of the at least one first function-icon and the at least one second function-icon and the at least one sequence-icon.

70. A method for programming a computer system including display means fordisplaying images to control at least one of a virtual instrument and an instrument, the method comprising the steps of: displaying on the screen at least one first function-icon that references at least one first control means for controlling at least one first function; displaying on the screen at least one iteration-icon that references iteration control means for controlling multiple iterations of data flow; displaying on the screen at least one feedback-icon that references feedback control means for controlling feedback of data; displaying on the screen at least one first input variable-icon that references at least one first input variable; displaying on the screen at least one first output variable-icon that references at least one first output variable; assembling on the screen at least one first acyclic data flow diagram including the at least one first function-icon and the at least one iteration-icon and the at least one feedback-icon and the at least one first input variable-icon and the at least one first output variable icon, such that the diagram displays a first procedure for producing at least one value for the at least one first output variable-icon from at least one value for the at least one first input variable-icon and such that the at least one iteration-icon in the diagram indicates multiple iterations of the at least one first function and such that the at least one feedback-icon in the diagram indicates that in the course of the multiple iterations, at least one value for the at least one first output variable-icon produced in at least one iteration of the at least one first function is used in a subsequent iteration of the at least one first function to produce at least one subsequent value for the at least one first output variable-icon.

71. The method of claim 70 and further comprising the step of: assembling on the screen a first front panel including the at least one first input variable-icon and the at least one first output variable-icon.

72. The method of claim 71 and further comprising the step of: simultaneously displaying on the screen the first front panel and the first data flow diagram.

73. A method for programming a computer system including display means for displaying images to control at least one of a virtual instrument and an instrument, the method comprising the steps of: providing a function class of respective function-icons that respectively reference respective control means for controlling respective functions; providing a scheduling class of respective scheduling-icons that respectively reference scheduling control means for scheduling of data flow, wherein the class of respective scheduling icons includes, (i) an iteration-icon that references iteration control means for controlling multiple iterations of data flow, and (ii) a conditional-icon that references conditional control means for controlling conditional branching of data flow; providing a variable class of respective variable-icons that respectively reference respective variables, selecting at least one first function-icon from the function class, the selected at least one first function-icon referencing at least one first control means; selecting at least one scheduling-icon from the scheduling class, the selected at least one scheduling-icon referencing at least one scheduling control means; selecting at least one first input variable-icon from the variable class; selecting at least one first output variable-icon from the variable class; and assembling on the screen a first acyclic data flow diagram including the selected at least one first function-icon and the selected at least one scheduling-icon and the at least one first input variable-icon and the at least one first output variable-icon, such that the diagram displays a first procedure for producing at least one value for the at least one first output variable-icon from at least one value for the at least one first input variable-icon and such that the selected scheduling-icon in the diagram indicates scheduling of the at least one first function in the course of the first procedure.

74. The method of claim 73 and further comprising the step of: assembling on the screen a first front panel including the at least one first input variable-icon and the at least one first output variable-icon.

75. The method of claim 74 and further comprising the step of: simultaneously displaying on the screen the first front panel and the first data flow diagram.

76. The method of claim 74 and further comprising the steps of: assigning at least one value for each at least one first input variable-icon; after assigning at least one value for each at least one first input variable-icon, producing at least one value for the at least one first output variable-icon from the at least one assigned value for each at least one first input variable-icon.

77. The method of claim 76 wherein said step of assigning includes the steps of: displaying said first front panel; setting the at least one first input variable-icon to display the at least one assigned value.

78. The method of claim 77 and further including the step of: displaying the at least one produced value in conjunction with the at least one first output variable-icon.

79. The method of claim 76 wherein said step of producing at least one value for the at least one first output variable-icon includes using said at least one first control means to control the first function.

80. The method of claim 79 wherein said step of producing at least one value for the at least one output variable-icon includes using the scheduling control means to control scheduling of data flow to the at least one first control means.

81. The method of claim 73 wherein said step of assembling on the screen the first diagram includes: arranging on the screen the at least one first function-icon and the at least one scheduling-icon such that in the first diagram the at least one first function-icon is displayed on the screen adjacent to the at least one scheduling-icon.

82. The method of claim 73 wherein said step of assembling on the screen the first diagram includes: arranging on the screen the at least one first function-icon and the at least one scheduling-icon such that in the first diagram the at least one first function-icon is displayed on the screen substantially inside the at least one scheduling-icon.

83. The method of claim 73 and further comprising the step of: selecting the at least one first control means.

84. The method of claim 83 and further comprising the step of selecting the at least one scheduling control means.

85. The method of claim 84 wherein: said steps of selecting the at least one first control means and selecting the at least one scheduling control means are performed automatically in the course of said steps of displaying on the screen the at least one first function-icon and displaying on the screen the at least one scheduling-icon and assembling on the screen the first diagram.

86. The method of claims 84 or 85 wherein said first control means and saidscheduling control means are substantially implemented in software.

87. The method of claim 84 and further comprising the steps of: reserving first input variable space in memory of the computer system corresponding to the selected at least one first input variable-icon; and reserving first output variable space in memory of the computer system corresponding to the selected at least one first output variable-icon.

88. The method of claim 87 wherein: said step of reserving first input variable space is performed automatically in the course of said steps of displaying the at least one first input variable-icon and assembling on the screen the first diagram; and said step of reserving first output variable space is performed automatically in the course of said steps of displaying the at least one first output variable-icon and assembling on the screen the first diagram.

89. The method of claim 87 wherein said step of assembling on the screen the first diagram further includes the steps of displaying on the screen at least one first input arc between the at least one first input variable-icon and at least one of the at least one first function-icon and the at least one scheduling-icon; and displaying on the screen at least one first output arc between the at least one first output variable-icon and at least one of the at least one first function-icon and the at least one scheduling-icon; and further comprising the steps of: forming first input means for moving respective input values for the at least one first input variable between the at least one first input variable space and at least one of the at least one first control means and the scheduling control means.

90. The method of claim 89 wherein: said step of forming first input means is performed automatically in the course of said step of displaying on the screen the at least one first input arc.

91. The method of claim 89 wherein: the at least one first control means and the scheduling control means and the first input means are substantially implemented in software.

92. The method of claim 89 and further comprising the steps of: assigning at least one value for each at least one first input variable-icon; storing in the reserved first input variable space each at least one assigned value; after said steps of assigning and storing at least one value for each at least one first input variable-icon, moving each at least one value for the at least one first input variable-icon from the reserved first input variable space to at least one of the at least one first control means and the scheduling control means using the first input means; after said steps of assigning and storing at least one value for each at least one first input variable-icon, producing at least one value for the at least one first output variable-icon using the at least one first control means to control the first function and using the scheduling control means to control scheduling data flow to the at least one first control means; and storing each value for the at least one first output variable-icon in the reserved first output variable space.

93. The method of claim 87 and further comprising the steps of: assigning at least one value for each at least one first input variable-icon; storing in the reserved first input variable space each at least one assigned value; after said steps of assigning and storing at least one value for each at least one first input variable-icon, producing at least one value for the at least one first output variable-icon; and storing each value for the at least one first output variable in the reserved first output variable space.

94. The method of claim 93 wherein: said step of storing each at least one assigned value is performed automatically in the course of said step of assigning.

95. The method of claim 73 wherein said step of assembling on the screen the first diagram further includes the steps of displaying at least one first input arc between the at least one first input variable-icon and at least one of the at least one first function-icon and the at least one scheduling-icon and displaying on the screen at least one first output arc between the at least one first output variable-icon and at least one of the at least one first function-icon and the at least one scheduling-icon.

96. The method of claim 73 wherein said step of providing a scheduling class includes providing in the scheduling class: (iii) a feedback-icon that references feedback control means for controlling feedback of data.

97. The method of claim 73 wherein said step of providing a scheduling class includes providing in the scheduling class: (iv) a sequence-icon that references sequencing control means for controlling sequencing of data flow.

98. A method for programming a computer system including means for displaying images on a screen to control at least one of a virtual instrument and an instrument, the method comprising the steps of: providing a class of respective function-icons that reference respective control means for controlling respective functions; selecting from the class of function-icons at least one first function-icon that references at least one first control means for controlling a first function; providing a class of respective variable-icons wherein each respective variable-icon references a respective variable; selecting at least one first input variable-icon from the class of variable-icons; selecting at least one first output variable-icon from the class of variable-icons; assembling on the screen a first front panel including the at least one first input variable-icon and the at least one first output variable-icon; and assembling on the screen a first data flow diagram including the at least one first function-icon and the at least one first input variable-icon and the at least one first output variable-icon, wherein the first diagram displays a first procedure for producing at least one value for the at least one first output variable-icon from at least one value for the at least one first input variable-icon.

99. The method of claim 98 and further comprising the step of: in the course of said step of assembling on the screen said front panel, displaying on the screen the at least one first input variable-icon and the at least one first output variable-icon.

100. The method of claim 98 and further comprising the step of: in the course of said step of assembling on the screen said first data flow diagram, displaying on the screen the at least one first function-icon and the at least one first input variable-icon and the at least one first output variable-icon.

101. The method of claim 98 and further comprising the step of: simultaneously displaying on the screen the first front panel and the first data flow diagram

102. The method of claim 98 and further comprising the steps of: assembling on the screen a first user-defined-function-icon that displays on the screen a reference to the first diagram; selecting from the class of function-icons at least one second function-icon that references at least one second control means for controlling a second function; selecting at least one second input variable-icon from the class of variable-icons; selecting at least one second output variable-icon from the class of variable-icons; assembling on the screen a second front panel including the at least one second input variable-icon and the at least one second output variable-icon; and assembling on the screen a second data flow diagram including the first user-defined-function-icon and the at least one second function-icon and the at least one second input variable-icon and the at least one second output variable-icon, wherein the second diagram displays a second procedure for producing at least one value for the at least one second output variable-icon from at least one value for the at least one second input variable-icon; whereby a hierarchy of diagrams is produced in which the first diagram is referenced by the first user-defined-function-icon in the second diagram.

103. The method of claim 102 and further comprising the steps of: assembling on the screen a second user-defined-function-icon that displays on the screen a reference to the second diagram; selecting from the class of function-icons at least one third function-icon that references at least one third control means for controlling a third function; selecting at least one third input variable-icon from the class of variable-icons; selecting at least one third output variable-icon from the class of variable-icons; assembling on the screen a third front panel including the at least one third input variable-icon and the at least one third output variable-icon; and assembling on the screen a third data flow diagram including the second user-defined-function-icon and the at least one third function-icon and the at least one third input variable-icon and the at least one third output variable-icon, wherein the third diagram displays a third procedure for producing at least one value for the at least one third output variable-icon from at least one value for the at least one third input variable-icon; whereby a hierarchy of diagrams is produced in which the first diagram is referenced by the first user-defined-function-icon in the second diagram and the second diagram is referenced by the second user-defined-function-icon in the third diagram.

104. The method of claim 103 and further comprising the steps of: assembling on the screen a third user-defined-function-icon that displays on the screen a reference to the third diagram; selecting from the class of function-icons at least one fourth function-icon that references at least one fourth control means for controlling a fourth function; selecting at least one fourth input variable-icon from the class of variable-icons; selecting at least one fourth output variable-icon from the class of variable-icons; assembling on the screen a fourth front panel including the at least one fourth input variable-icon and the at least one fourth output variable-icon; and assembling on the screen a fourth data flow diagram including the third user-defined-function-icon and the at least one fourth function-icon and the at least one fourth input variable-icon and the at least one fourth output variable-icon, wherein the fourth diagram displays a fourth procedure for producing at least one value for at least one fourth output variable-icon from at least one value for the at least one fourth input variable-icon; whereby a hierarchy of diagrams is produced in which the first diagram is referenced by the first user-defined-function-icon in the second diagram and the second diagram is referenced by the second user-defined-function-icon in the third diagram and the third diagram is referenced by the third user-defined-function-icon in the fourth diagram.

105. The method of claim 104 and further comprising the steps of: assembling on the screen an (n-1)th user-defined-function-icon that displays on the screen a reference to an (n-1)th data flow diagram, wherein n is an integer and n.gtoreq.5; selecting at least one nth function-icon from the class of function-icons; selecting at least one nth input variable-icon from the class of variable-icons; selecting at least one nth output variable-icon from the class of variable-icons; assembling on the screen an nth front panel including the at least one nth input variable-icon and the at least one nth output variable-icon, and assembling on the screen an nth data flow diagram including the (n-1)th user-defined-function-icon and the at least one nth function-icon and the at least one nth input variable-icon and the at least one nth output variable-icon, wherein the nth diagram displays an nth procedure for producing at least one value for the at least one nth output variable-icon from at least one value for the at least one nth input variable-icon; whereby a hierarchy of diagrams is produced in which the (n-1)th diagram is referenced by the (n-1)th user-defined-function-icon in the nth diagram.

106. The method of claim 102 wherein said step of assembling on the screen a first user-defined-function-icon includes the steps of: displaying on the screen at least one panel-pattern-icon from a set of respective panel-pattern-icons wherein each respective panel-pattern-icon references a distinct arrangement of panels; selecting a first panel-pattern-icon from the set of panel-pattern-icons; displaying on the screen the first panel-pattern-icon and the at least one first input variable-icon; displaying on the screen the first panel-pattern-icon and the at least one first output variable-icon; defining an association between at least one first input panel of the first panel-pattern-icon and the at least one first input variable-icon; and defining an association between at least one first output panel of the first panel-pattern-icon and the at least one first output variable-icon.

107. The method of claim 106 and further comprising the step of: in the course of said step of defining an association between the at least one first input panel of the first panel-pattern-icon and the at least one first input variable-icon, displaying the defined association between the at least one first input panel of the first panel-pattern--icon and the at least one first input variable-icon; and in the course of said step of defining an association between the at least first output panel of the first panel-pattern-icon and the at least one first output variable-icon, displaying the defined association between the at least one first output panel of the first panel-pattern-icon and the at least one first output variable-icon.

108. The method of claim 98 and further comprising the step of: displaying on the the screen a first menu identifying a class of functions that respectively correspond to the function-icons of the class of function-icons.

109. The method of claim 98 and further comprising the steps of: displaying on the screen a first menu identifying a class of functions that respectively correspond to the function-icons of the class of function-icons; and displaying on the screen a second menu identifying a class of variables that respectively correspond to the variable-icons of the class of variable-icons.

110. The method of claim 265 and further comprising the step of:selecting the at least one first control means.

111. The method of claim 110 wherein: said step of selecting the at least one first control means is performed automatically in the course of said steps of selecting the at least one first function-icon and assembling on the screen the first front panel and assembling on the screen the first diagram.

112. The method of claims 110 or 111 wherein said first control means is substantially implemented in software.

113. The method of claim 110 and further comprising the steps of: reserving first input variable space in memory of the computer system corresponding to the selected at least one first input variable-icon; and reserving first output variable space in memory of the computer system corresponding to the selected at least one first output variable-icon.

114. The method of claim 113 wherein: said step of reserving first input variable space is performed automatically in the course of said steps of selecting the at least one first input variable-icon and assembling on the screen the first front panel and assembling on the screen the first diagram; and said step of reserving first output variable space is performed automatically in the course of said steps of selecting the at least one first output variable-icon and assembling on the screen the first front panel and assembling on the screen the first diagram.

115. The method of claim 113 wherein said step of assembling on the screen the first diagram further includes the steps of displaying on the screen at least one first input arc between the at least one first input variable-icon and the at least one first function-icon and displaying on the screen at least one first output arc between the at least one first output variable-icon and the at least one first function-icon; and further comprising the steps of: forming first input means for moving respective input values for the at least one first input variable between the at least one first input variable space and the at least one first control means.

116. The method of claim 115 wherein: said step of forming first input means is performed automatically in the course of said step of displaying on the screen the at least one first input arc.

117. The method of claim 115 wherein: the at least one first control means and the first input means are substantially implemented in software.

118. The method of claim 115 and further comprising the steps of: assigning at least one value for each at least one first input variable-icon; storing in the reserved first input variable space each at least one assigned value; after said steps of assigning and storing at least one value for each at least one first input variable-icon, moving each at least one value for the at least one first input variable-icon from the reserved first input variable space to the at least one first control means using the first input means; after said steps of assigning and storing at least one value for each at least one first input variable-icon, producing at least one value for the at least one first output variable-icon using the at least one first control means to control the first function; and storing each value for the at least one first output variable-icon in the reserved first output variable space.

119. The method of claim 113 and further comprising the steps of: assigning at least one value for each at least one first input variable-icon; storing in the reserved first input variable space each at least one assigned value; after said steps of assigning and storing at least one value for each at least one first input variable-icon, producing at least one value for the at least one first output variable-icon; and storing each value for the at least one first output variable in the reserved first output variable space.
120. The method of claim 119 wherein: said step of storing each at least one assigned value is performed automatically in the course of said step of assigning.

121. The method of claim 98 wherein said step of assembling on the screen the first diagram further includes the steps of displaying at least one first input arc between the at least one first input variable-icon and the at least one first function-icon and displaying on the screen at least one first output arc between the at least one first output variable-icon and the at least one first function-icon.

122. The method of claim 98 and further comprising the steps of: assigning at least one value for each at last one first input variable-icon; after assigning at least one value for each at least one first input variable-icon, producing at least one value for the at least one first output variable-icon from the at least one value for each at least one first input variable-icon.

123. The method of claim 122 wherein said step of assigning includes the steps of: displaying said first front panel; and instructing the at least one first input variable-icon to display the at least one assigned value.

124. The method of claim 287 and further including the step of: displaying the at least one produced value in conjunction with the at least one first output variable-icon.

125. The method of claim 122 wherein said step of producing at least one value for the at least one first output variable-icon includes using said at least one first control means to control the first function.