mirror of https://github.com/Askill/AP-SCE.git
51 lines
1.0 KiB
C++
51 lines
1.0 KiB
C++
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#include "mex.h"
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#include "matrix.h"
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#include "stdlib.h"
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void mexFunction(int nlhs, mxArray *plhs[], // Output
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int nrhs, const mxArray *prhs[]) // Input
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{
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int num_data_points = *mxGetPr(prhs[0]);
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double* x = (double *)mxCalloc(num_data_points, sizeof(double));
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double* y = (double *)mxCalloc(num_data_points, sizeof(double));
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double* temp = (double *)mxCalloc(num_data_points, sizeof(double));
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for(int j=0; j < num_data_points; j++)
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{
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x[j] = mxGetPr(prhs[1])[j];
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y[j] = mxGetPr(prhs[2])[j];
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}
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//Mid-diff
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int i = 0;
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temp[i] = (y[i+1] - y[i]) / (x[i+1] - x[i]);
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i++;
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temp[i] = (y[i+1] - y[i]) / (x[i+1] - x[i]);
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temp[i] += (y[i+1] - y[i-1]) / (x[i+1] - x[i-1]);
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temp[i] /= 2;
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for (; i < num_data_points - 2; ++i)
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{
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temp[i] = (y[i+1] - y[i-1] ) / (x[i+1] - x[i-1]);
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}
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temp[i] += (y[i] - y[i-1]) / (x[i] - x[i-1]);
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temp[i] /= 2;
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i++;
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temp[i] = (y[i] - y[i-1]) / (x[i] - x[i-1]);
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// Output
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nlhs = num_data_points;
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for(int j=0; j < num_data_points; j++){
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plhs[j]=mxCreateDoubleScalar(temp[j]);
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}
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return;
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}
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