This routine computes the min, max, absolute deviation and first four order moment of a data set

Location in HEALPix directory tree: src/f90/mod/statistics.f90

FORMAT

call compute_statistics*( data ,stats [, badval] )

ARGUMENTS

name & dimensionality	kind	in/out	description

data(:)	SP/ DP	IN	data set
stats	tstats	OUT	structure containing the statistics of the data. The respective fields (stats%field) are:
ntot	I4B	-	total number of data points
nvalid	I4B	-	number n of valid data points
mind, maxd	DP	-	minimum and maximum valid data
average	DP	-	average of valid points $m= \sum x / n$
absdev	DP	-	absolute deviation $a= \sum\vert x-m\vert/n$
var	DP	-	variance $\sigma^2 = \sum(x-m)^2/ (n-1)$
rms	DP	-	standard deviation $\sigma$
skew	DP	-	skewness factor $s = \sum(x-m)^3 / (n\sigma^3)$
kurt	DP	-	kurtosis factor $k = \sum(x-m)^4 / (n\sigma^4) - 3$

badval (OPTIONAL)	SP/ DP	IN	sentinel value given to bad data points. Data points with this value will be ignored during calculation of the statistics. If not set, all points will be considered. Do not set to 0!.

EXAMPLE:

use statistics, only: compute_statistics, print_statistics, tstats type(tstats) :: stats ... compute_statistics(map, stats) print*,stats%average, stats%rms print_statistics(stats)

Computes the statistics of map, prints its average and rms and prints the whole list of statistical measures.

RELATED ROUTINES

This section lists the routines related to compute_statistics*

median: routine to compute median of a data set

Eric Hivon 2010-06-18

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