31 lines
682 B
C
31 lines
682 B
C
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#include <math.h>
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void moment(float data[], int n, float *ave, float *adev, float *sdev,
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float *var, float *skew, float *curt)
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{
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void nrerror(char error_text[]);
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int j;
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float ep=0.0,s,p;
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if (n <= 1) nrerror("n must be at least 2 in moment");
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s=0.0;
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for (j=1;j<=n;j++) s += data[j];
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*ave=s/n;
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*adev=(*var)=(*skew)=(*curt)=0.0;
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for (j=1;j<=n;j++) {
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*adev += fabs(s=data[j]-(*ave));
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ep += s;
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*var += (p=s*s);
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*skew += (p *= s);
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*curt += (p *= s);
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}
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*adev /= n;
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*var=(*var-ep*ep/n)/(n-1);
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*sdev=sqrt(*var);
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if (*var) {
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*skew /= (n*(*var)*(*sdev));
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*curt=(*curt)/(n*(*var)*(*var))-3.0;
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} else nrerror("No skew/kurtosis when variance = 0 (in moment)");
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}
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