compare

Class: FunctionApproximation.LUTSolution
Package: FunctionApproximation

Compare numerical results of FunctionApproximation.LUTSolution to original function or lookup table

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Syntax

data = compare(solution)

Description

data = compare(solution) plots the difference between the data contained in the FunctionApproximation.LUTSolution object, solution, and the original lookup table, function, or Math Function block.

Input Arguments

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The solution to compare original behavior against, specified as a FunctionApproximation.LUTSolution object.

Output Arguments

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Struct containing data comparing the original function or lookup table and the approximation contained in the solution.

Examples

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Open Live Script

Create a FunctionApproximation.Problem object defining the function you want to approximate.

problem = FunctionApproximation.Problem('tanh')
problem = 
  1x1 FunctionApproximation.Problem with properties:

    FunctionToApproximate: @(x)tanh(x)
           NumberOfInputs: 1
               InputTypes: "numerictype(1,16,12)"
         InputLowerBounds: -8
         InputUpperBounds: 8
               OutputType: "numerictype(1,16,15)"
                  Options: [1x1 FunctionApproximation.Options]

Use default values for all other options. Approximate the tanh function using the solve method.

solution = solve(problem)
|  ID |  Memory (bits) | Feasible | Table Size | Breakpoints WLs | TableData WL | BreakpointSpecification |             Error(Max,Current) | 
|   0 |             64 |        0 |          2 |              16 |           16 |             EvenSpacing |     7.812500e-03, 9.999998e-01 |
|   1 |           1248 |        1 |         76 |              16 |           16 |             EvenSpacing |     7.812500e-03, 4.368265e-03 |
|   2 |           1232 |        1 |         75 |              16 |           16 |             EvenSpacing |     7.812500e-03, 4.439035e-03 |
|   3 |            944 |        1 |         57 |              16 |           16 |             EvenSpacing |     7.812500e-03, 7.780470e-03 |
|   4 |            928 |        1 |         56 |              16 |           16 |             EvenSpacing |     7.812500e-03, 6.110240e-03 |
|   5 |            656 |        0 |         39 |              16 |           16 |             EvenSpacing |     7.812500e-03, 1.678519e-02 |
|   6 |            640 |        0 |         38 |              16 |           16 |             EvenSpacing |     7.812500e-03, 1.660649e-02 |
|   7 |            784 |        0 |         47 |              16 |           16 |             EvenSpacing |     7.812500e-03, 1.102459e-02 |
|   8 |            848 |        1 |         51 |              16 |           16 |             EvenSpacing |     7.812500e-03, 6.211764e-03 |
|   9 |            816 |        1 |         49 |              16 |           16 |             EvenSpacing |     7.812500e-03, 6.811833e-03 |
|  10 |            800 |        0 |         48 |              16 |           16 |             EvenSpacing |     7.812500e-03, 1.105540e-02 |
|  11 |            432 |        0 |         25 |              16 |           16 |             EvenSpacing |     7.812500e-03, 3.532625e-02 |
|  12 |            624 |        0 |         37 |              16 |           16 |             EvenSpacing |     7.812500e-03, 1.870074e-02 |
|  13 |            720 |        0 |         43 |              16 |           16 |             EvenSpacing |     7.812500e-03, 1.355547e-02 |
|  14 |            768 |        0 |         46 |              16 |           16 |             EvenSpacing |     7.812500e-03, 1.199717e-02 |
|  15 |            384 |        1 |         12 |              16 |           16 |          ExplicitValues |     7.812500e-03, 7.812317e-03 |
|  16 |            384 |        0 |         12 |              16 |           16 |          ExplicitValues |     7.812500e-03, 1.196141e-02 |
|  17 |            384 |        1 |         12 |              16 |           16 |          ExplicitValues |     7.812500e-03, 7.812317e-03 |

Best Solution
|  ID |  Memory (bits) | Feasible | Table Size | Breakpoints WLs | TableData WL | BreakpointSpecification |             Error(Max,Current) |
|  15 |            384 |        1 |         12 |              16 |           16 |          ExplicitValues |     7.812500e-03, 7.812317e-03 |

solution = 
  1x1 FunctionApproximation.LUTSolution with properties:

          ID: 15
    Feasible: "true"

Compare the original function and the function approximation.

data = compare(solution)

data = struct with fields:
    Breakpoints: [65536x1 double]
       Original: [65536x1 double]
    Approximate: [65536x1 double]

See Also

Apps

Classes

Functions

Topics

Introduced in R2018a

Fixed-Point Designer Documentation

Support