generateMATLABFunction - Create MATLAB function compatible with C/C++ code generation - MATLAB (original) (raw)

Create MATLAB function compatible with C/C++ code generation

Since R2021b

Syntax

Description

generateMATLABFunction([sFE](#mw%5F4fecfa0a-43ff-4d48-9af8-9906262d4509)) generates code based on the input feature extractor object sFE and opens an untitled file containing the function extractSignalFeatures. The function signature depends on how you set the FeatureFormat property of the input feature extractor object.

• When you specify FeatureFormat as"matrix", the generated MATLAB® function has this signature:
  [features,info,framelimits] = extractSignalFeatures(x)
  The signature is equivalent to:
  [features,info,framelimits] = extract(sFE,x)
• When you specify FeatureFormat as "table", the generated MATLAB function has this signature:
  features = extractSignalFeatures(x)
  The signature is equivalent to:
  features = extract(sFE,x)

example

Examples

collapse all

Create a signalTimeFeatureExtractor object to extract the mean, standard deviation, and peak value of a random signal.

x = randn(1000,1); sFE = signalTimeFeatureExtractor(FrameSize=100, ... FrameOverlapLength=10,Mean=true,StandardDeviation=true, ... PeakValue=true)

sFE = signalTimeFeatureExtractor with properties:

Properties
           FrameSize: 100
  FrameOverlapLength: 10
          SampleRate: []
 IncompleteFrameRule: "drop"
       FeatureFormat: "matrix"

Enabled Features
  Mean, StandardDeviation, PeakValue

Disabled Features
  RMS, ShapeFactor, SNR, THD, SINAD, CrestFactor
  ClearanceFactor, ImpulseFactor

Call generateMATLABFunction on the object. The generated function extractSignalFeatures is equivalent to calling theextract function on sFE. Save the function to your current folder and view the function script.

generateMATLABFunction(sFE) type extractSignalFeatures

function [features,info,frameLimits] = extractSignalFeatures(x) % EXTRACTSIGNALFEATURES Extract signal features % [FEATURES,INFO,FRAMELIMITS] = extractSignalFeatures(X) returns a matrix % containing features extracted from input X, INFO, a structure that maps % a specific feature to its column location in the output feature matrix % and FRAMELIMITS, whose i-th row contains the beginning and end limits % of the i-th frame. % % Parameters of the signalTimeFeatureExtractor used to generate this % function must be honored when calling this function.

% Generated by MATLAB(R) 9.11 and Signal Processing Toolbox 8.7. % Generated on: 10-Jun-2021 08:25:02.

%#codegen

if istimetable(x) xInTT = x{:,:}; else xInTT = x; end if isrow(xInTT) xIn = xInTT(:); else xIn = xInTT; end dataType = class(xIn); signalLength = size(xIn,1); numChannels = size(xIn,2); frameSize = 100; frameOverlapLength = 10; frameRate = frameSize - frameOverlapLength; featureMatrix = zeros(0,1,dataType); numFeatureCols = 0; numFeatureRows = 0; frameLimits = zeros(0,2,dataType); info = struct('Mean',0,'StandardDeviation',0,'PeakValue',0); for idx = 1:numChannels if numChannels == 1 xChannel = xIn; else xChannel = xIn(:,idx); end startIdx = 1; endIdx = frameSize; while startIdx <= signalLength if endIdx > signalLength break; end featureIndex = 1; xFrame = xChannel(startIdx:endIdx,1); meanValue = mean(xFrame); numCurrentFeature = numel(meanValue); info.Mean = featureIndex; featureIndex = featureIndex+numCurrentFeature;

    standardDeviation = std(xFrame);
    numCurrentFeature = numel(standardDeviation);
    info.StandardDeviation = featureIndex;
    featureIndex = featureIndex+numCurrentFeature;

    peakValue = max(abs(xFrame));
    info.PeakValue = featureIndex;

    featureVector = [meanValue(:);standardDeviation(:);peakValue(:)];
    featureMatrix = [featureMatrix;featureVector];
    if startIdx == 1
        numFeatureCols = size(featureVector,1);
    end
    if idx == 1
        numFeatureRows = numFeatureRows+1;
        frameLimits = [frameLimits;[startIdx endIdx]];
    end
    startIdx = startIdx+frameRate;
    endIdx = startIdx+frameSize-1;
end

end tempFeatureMatrix = reshape(featureMatrix,numFeatureCols,numFeatureRows,numChannels); features = permute(tempFeatureMatrix,[2,1,3]); end

You can replace calls to extract with calls to the generated function in your code. The outputs are identical.

features1 = extract(sFE,x)

features1 = 11x3 0.0842 1.0690 2.7526 0.0500 1.0516 2.9491 0.1901 1.0356 2.7304 0.1209 0.9171 2.4366 0.0443 0.9399 2.4247 -0.1153 1.0490 3.5699 -0.1001 0.9530 2.4124 0.0616 0.9959 2.7485 -0.0263 0.9482 2.4868 -0.0234 0.9876 3.1585 . . .

features2 = extractSignalFeatures(x)

features2 = 11x3 0.0842 1.0690 2.7526 0.0500 1.0516 2.9491 0.1901 1.0356 2.7304 0.1209 0.9171 2.4366 0.0443 0.9399 2.4247 -0.1153 1.0490 3.5699 -0.1001 0.9530 2.4124 0.0616 0.9959 2.7485 -0.0263 0.9482 2.4868 -0.0234 0.9876 3.1585 . . .

Copyright 2020 The MathWorks, Inc.

Input Arguments

Version History

Introduced in R2021b