mean.c File Reference

Functions for calculating mean and stdev. More...

#include "tpcclibConfig.h"
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>
#include "tpcextensions.h"
#include "tpcstatist.h"

Go to the source code of this file.

Functions
int	statMeanSD (double *data, unsigned int n, double *mean, double *sd, unsigned int *vn)
int	fstatMeanSD (float *data, unsigned int n, float *mean, float *sd, unsigned int *vn)

Detailed Description

Functions for calculating mean and stdev.

Definition in file mean.c.

Function Documentation

fstatMeanSD()

int fstatMeanSD	(	float *	data,
		unsigned int	n,
		float *	mean,
		float *	sd,
		unsigned int *	vn )

Calculate mean and sample standard deviation in an array of given float data. NaNs in the data are left out.

Author

Vesa Oikonen

See also

statMeanSD, floatMean, floatSum, floatMatch

Returns

0 if successful, otherwise <>0.

Parameters

data	Pointer to data array of size n; data is not changed in any way.
n	Length of data array.
mean	Pointer to variable where mean will be written; enter NULL if not needed.
sd	Pointer to variable where SD will be written; enter NULL if not needed.
vn	Pointer to variable where the number of valid (not NaN) samples will be written; enter NULL if not needed.

Definition at line 73 of file mean.c.

  {
  unsigned int i, m;
  float sumsqr=0.0, sqrsum=0.0;
 
  if(mean!=NULL) *mean=nanf(""); 
  if(sd!=NULL) *sd=nanf(""); 
  if(vn!=NULL) *vn=0;
  if(n<1 || data==NULL) return(1);
  for(i=m=0; i<n; i++) if(!isnan(data[i])) m++;
  if(m<1) return(2);
  if(vn!=NULL) *vn=m;
 
  /* Calculate mean, and sum for possible SD calculation */
  for(i=0; i<n; i++) if(!isnan(data[i])) sqrsum+=data[i];
  if(mean!=NULL) *mean=sqrsum/(float)m;
  
  /* Calculate SD, if required */
  if(sd==NULL) return(0);
  if(m==1) {*sd=0.0; return(0);}
  sqrsum*=sqrsum;
 
  for(i=0; i<n; i++) if(!isnan(data[i])) sumsqr+=data[i]*data[i];
  float ff=sumsqr - sqrsum/(float)m; if(!(ff>0.0)) {*sd=0.0; return(0);}
  *sd=sqrtf( ff/(float)(m-1) );
 
  return(0);
}

statMeanSD()

int statMeanSD	(	double *	data,
		unsigned int	n,
		double *	mean,
		double *	sd,
		unsigned int *	vn )

Calculate mean and sample standard deviation in an array of given data. NaNs in the data are left out.

Author

Vesa Oikonen

See also

statMedian, doubleMean, doubleWMean, floatMean, fitLine, statSortDouble, doubleMatch, doubleRange, fstatMeanSD

Returns

0 if successful, otherwise <>0.

Parameters

data	Pointer to data array of size n; data is not changed in any way.
n	Length of data array.
mean	Pointer to variable where mean will be written; enter NULL if not needed.
sd	Pointer to variable where SD will be written; enter NULL if not needed.
vn	Pointer to variable where the number of valid (not NaN) samples will be written; enter NULL if not needed.

Definition at line 25 of file mean.c.

  {
  unsigned int i, m;
  double sumsqr=0.0, sqrsum=0.0;
 
  if(mean!=NULL) *mean=nan(""); 
  if(sd!=NULL) *sd=nan(""); 
  if(vn!=NULL) *vn=0;
  if(n<1 || data==NULL) return(1);
  for(i=m=0; i<n; i++) if(!isnan(data[i])) m++;
  if(m<1) return(2);
  if(vn!=NULL) *vn=m;  
 
  /* Calculate mean, and sum for possible SD calculation */
  for(i=0; i<n; i++) if(!isnan(data[i])) sqrsum+=data[i];
  if(mean!=NULL) *mean=sqrsum/(double)m;
  
  /* Calculate SD, if required */
  if(sd==NULL) return(0);
  if(m==1) {*sd=0.0; return(0);}
  sqrsum*=sqrsum;
 
  for(i=0; i<n; i++) if(!isnan(data[i])) sumsqr+=data[i]*data[i];
  double ff=sumsqr - sqrsum/(double)m; if(!(ff>0.0)) {*sd=0.0; return(0);}
  *sd=sqrt( ff/(double)(m-1) );
 
  return(0);
}

Referenced by nloptIATGO(), nloptMPSOabsvMean(), and nloptMPSOpMean().