Rasterscan display with adaptive decay

• US 5,387,896 A
• Filed: 08/06/1990
• Issued: 02/07/1995
• Est. Priority Date: 08/06/1990
• Status: Expired due to Term

• Current Assignee: Tektronix Incorporated (Fortive Corp.)
• Original Assignee: Tektronix Incorporated (Fortive Corp.)
• Inventors: Alappat, Kuriappan P., Averill, Edward E.
• Primary Examiner(s): Oberley, Alvin E.
• Assistant Examiner(s): SARAS, STEVEN J
• Application Number:
  US07/563,656
• Time in Patent Office: 1,646 Days
• Field of Search: 342/176, 342/185, 342/195, 324/88, 324/121 R, 340/721, 340/722, 340/723, 340/744, 340/747, 340/793, 340/799, 345/133, 345/134, 345/185, 345/200, 345/203, 345/147
• US Class Current: 345/440
• CPC Class Codes: G01R 13/02 for displaying measured electric variables in digital form

Abstract

Apparatus for manipulating numerical values stored in a memory comprises a modify device for receiving numerical values from the memory and returning numerical values to the memory. The modify device has at least a first state in which it modifies a numerical value received from the memory in a predetermined fashion before returning the numerical value to the memory and a second state in which it does not modify a numerical value received from the memory in the predetermined fashion before returning the numerical value to the memory. The apparatus also comprises a characterizing device for examining at least some of the numerical values and calculating at least one number that defines a property of the examined numerical values. The characterizing device is connected to the modify device for placing the modify device in the first state or the second state depending on the value of the calculated number.

Claims

1. Apparatus for manipulating numerical values stored in a memory, said apparatus comprising:

modify means for receiving numerical values from the memory and returning numerical values to the memory, said modify means having at least a first state in which the numerical value received from the memory is modified in a predetermined fashion before returning the numerical value to the memory and a second state in which the numerical value received from the memory is not modified in said predetermined fashion before returning the numerical value to the memory, and

characterizing means for examining at least some of the numerical values and calculating at least one number that defines a property of the examined numerical values, said characterizing means being connected to the modify means for placing the modify means in the first state or the second state depending on the value of said number, the characterizing means comprising;

means for counting the number of numerical values that bear a predetermined relationship to a first value and for counting the number of numerical values that bear a predetermined relationship to a second value, and

means for comparing the number of numerical values that bear said predetermined relationship to said first value with the number of numerical values that bear said predetermined relationship to said second value.

2. A method of operating apparatus for receiving data representing events defined by respective pairs of values of first and second variable, said method comprising:

(a) storing numerical values representative of the number of occurrences of each event,

(b) examining at least some of the stored numerical values and calculating at least one number that defines a property of the examined numerical values, the examination comprising comparing the number of numerical values exceeding a first value with the number of numerical values exceeding a second value,

(c) modifying the stored numerical values in a fashion that depends on the calculated number, the modification comprising decrementing each numerical value employing an operating number of which the value depends on the result of the comparison, and

(d) employing the modified numerical values to provide a graphic display of the function that relates the first and second variables.

3. A method of operating apparatus for receiving data representing events defined by respective pairs of values of first and second variable, the numerical values are stored in a finite address space, and each pair of values of the first and second variables defines a memory location within the finite address space, said method comprising:

(a) storing numerical values representative of the number of occurrences of each event,

(b) examining at least some of the stored numerical values and calculating at least one number that defines a property of the examined numerical values, the examination comprising comparing the number of numerical values exceeding a first value with the number of numerical values exceeding a second value,

(c) modifying the stored numerical values in a fashion that depends on the calculated number,

(d) employing the modified numerical values to provide a graphic display of the function that relates the first and second variables

(e) acquiring data representative of the occurrence of a subsequent event,

(f) identifying the location within the finite address space that represents said event, and

(g) incrementing the numerical value stored at said location employing an operating number of which the value depends on the result of the comparison.