Optimized look-up table calculations in block diagram software

• US 20070261021A1
• Filed: 07/24/2007
• Published: 11/08/2007
• Est. Priority Date: 07/20/2001
• Status: Active Grant

• Current Assignee: The MathWorks, Inc.
• Original Assignee: The MathWorks, Inc.
• Inventors: Aberg, Robert
• Granted Patent: US 8,234,625 B2
• Time in Patent Office: Days
• US Class Current: 717/105
• CPC Class Codes: G06F 8/34 Graphical or visual programming
• CPC Class Codes: Y10S 707/99945 Object-oriented database structure processing
• CPC Class Codes: Y10S 707/99948 Application of database or data structure, e.g. distributed, multimedia, or image

Abstract

Pre-lookup index search blocks and multidimensional interpolation blocks that use the results of the pre-lookup index search blocks in a block diagram to graphically specify (and perform) multidimensional interpolation calculations. The pre-lookup index search and interpolation blocks are defined so as to provide for a separation of breakpoint set data and table data, thus enabling a user to explicitly manage the use of common breakpoint set data. A block diagram created using pre-lookup index search blocks and interpolation using pre-lookup index search blocks shows all tables that use a particular breakpoint set via graphical connections on the block diagram between the pre-lookup index search blocks and the interpolation using pre-lookup index search blocks.

Claims

1. A method comprising:

performing an index search operation using an input value to determine an interval in which the input value resides;

in the first block, calculating a first set of output values;

providing the first set of output values to one or more interpolation blocks, wherein the one or more interpolation blocks perform an interpolation operation using the first set of output values; and

storing one or more output values of the one or more interpolation blocks in a storage device.

2. The method of claim 1, wherein the first block is a pre-lookup index search block associated with a breakpoint data array, wherein the breakpoint data array comprises an ordered list of indexed values of length N.

3. The method of claim 2, wherein the ordered list of values defines a set of regions that includes regions corresponding to a set of N−

1 intervals.

4. The method of claim 1, wherein the first set of output values comprises:

a first interval index indicating an interval in which the input value resides; and

a first distance fraction indicating normalized distance on the interval indicated by the first interval index.

5. The method of claim 4, further comprising:

using a linear index search to determine a value of the first interval index, wherein the linear index search comprises;

checking consecutive N−

1 intervals to determine if the input value resides in the interval; and

setting the value of the first interval index to be equal to value of the interval where the input value resides.

6. The method of claim 1, further comprising:

performing an index search operation using a second block to determine an interval in which a second input value resides;

in the second block, calculating a second set of output values; and

providing the first set of output values or the second set of output values to the one or more interpolation blocks, wherein the one or more interpolation blocks perform an interpolation operation using the first set of output values or the second set of output values.

7. The method of claim 6, wherein the second block is a pre-lookup index search block associated with a breakpoint data array, wherein the breakpoint data array comprises an ordered list of values of length N.

8. The method of claim 7, wherein the ordered list of values defines a set of regions that includes regions corresponding to a set of N−

1 intervals.

9. The method of claim 6, wherein the second set of output values comprises:

a second interval index indicating the interval in which the second input value resides; and

a second distance fraction indicating normalized distance on the interval indicated by the second interval index.

10. The method of claim 6, wherein the first block, the second block, or the interpolation blocks reside in a library accessible by one or more users.

11. A computer-readable medium holding instructions for splitting table lookup operation into an index search operation and an interpolation operation, the medium comprising:

instructions for performing an index search operation using an input value to determine an interval in which the input value resides;

instructions for calculating a first set of output values in the first block;

instructions for performing an index search operation using a second input value to determine an interval in which the second input value resides;

instructions for calculating a second set of output values in the second block;

instructions for providing the first set of output values or the second set of output values to the one or more interpolation blocks, wherein the one or more interpolation blocks perform an interpolation operation using the first set of output values or the second set of output values; and

instructions for storing one or more output values of the one or more interpolation blocks in a storage device.

12. The medium of claim 11, wherein the first set of output values or the second set of output values comprises:

an interval index indicating an interval in which an input value resides; and

a distance fraction indicating normalized distance on the interval indicated by the interval index.

13. The medium of claim 11, wherein the first block and the second block are pre-lookup index search blocks, associated with one or more breakpoint data arrays, wherein the one or more breakpoint data arrays comprise an ordered list of values of length N.

14. The medium of claim 13, wherein the ordered list of values defines a set of regions that includes regions corresponding to a set of N−

1 intervals.

15. The medium of claim 11, wherein the first block, the second block and the interpolation blocks reside in a library accessible by one or more users.

16. A computer system comprising a graphical modeling environment, the system comprising:

means for performing an index search operation using an input value to determine an interval in which the input value resides;

means for calculating a first set of output values in the first block and a second set of output values in the second block;

means for providing the first set of output values and the second set of output values to the one or more interpolation blocks, wherein the one or more interpolation blocks perform an interpolation operation using the first set of output values and the second set of output values;

means for storing one or more outputs of the one or more interpolation blocks; and

means for displaying one or more graphical user interfaces (GUI) for displaying a pre-lookup index search block or an interpolation block to a user.

17. The system of claim 16, wherein one of the one or more GUIs displays the pre-lookup index search block, the one of the one or more GUIs interacting with:

means for specifying a breakpoint data array for the pre-lookup index search block;

means for specifying an index search algorithm;

or

means for specifying an extrapolation method.

18. The system of claim 16, wherein one of the one or more GUIs displays the interpolation block, the one of the one or more GUIs interacting with:

means for specifying a number of table dimensions;

means for specifying entries for a table data;

means for specifying an interpolation method;

or

means for specifying an extrapolation method.

19. The system of claim 16, further comprising:

means for interpreting the graphical model when a two-step interpolation technique is specified by a user.