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C Library Functions  - norpdf (3)

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NAME

norpdf(3f) - [M_datapac:PROBABILITY_DENSITY] compute the normal probability density function

CONTENTS

Synopsis
Description
Input Arguments
Output Arguments
Examples
Author
Maintainer
License
References

SYNOPSIS

SUBROUTINE NORPDF(X,Pdf)

       REAL(kind=wp),intent(in)  :: X
       REAL(kind=wp),intent(out) :: Pdf

DESCRIPTION

NORPDF(3f) computes the probability density function value for the normal (Gaussian) distribution with mean = 0 and standard deviation = 1.

This distribution is defined for all X and has the probability density function

       f(X) = (1/sqrt(2*pi))*exp(-X*X/2)

INPUT ARGUMENTS

X	The value at which the probability density function is to be evaluated.

OUTPUT ARGUMENTS

PDF	The probability density function value.

EXAMPLES

Sample program:

   program demo_norpdf
   !@(#) line plotter graph of probability density function
   use M_datapac, only : norpdf, plott, label
   implicit none
   real,allocatable  :: x(:), y(:)
   integer           :: i
      call label(’norpdf’)
      x=[(real(i),i=-100,100,1)]
      if(allocated(y))deallocate(y)
      allocate(y(size(x)))
      do i=1,size(x)
         call norpdf(x(i)/10.0,y(i))
      enddo
      call plott(x,y,size(x))
   end program demo_norpdf

Results:

AUTHOR

The original DATAPAC library was written by James Filliben of the Statistical Engineering Division, National Institute of Standards and Technology.

MAINTAINER

John Urban, 2022.05.31

LICENSE

CC0-1.0

REFERENCES

o	Johnson and Kotz, Continuous Univariate Distributions--1, 1970, pages 40-111.

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Nemo Release 3.1

norpdf (3)

February 23, 2025

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