Home > wafo > wstats > wnormpdf.m

wnormpdf

PURPOSE ^

Normal probability density function

SYNOPSIS ^

f = wnormpdf(x,m,v);

DESCRIPTION ^

 WNORMPDF Normal probability density function 
  
  CALL:  f = wnormpdf(x,m,v); 
  
         f = density function evaluated at x 
         m = mean     (default 0) 
         v = variance (default 1) 
   
  Example:  
    x = linspace(-3,3,200); 
    p1 = wnormpdf(x,0,1); p2 = wnormpdf(x,.5,0.25); 
    plot(x,p1,x,p2)

CROSS-REFERENCE INFORMATION ^

This function calls: This function is called by:

SOURCE CODE ^

001 function f = wnormpdf(x,m,v); 
002 %WNORMPDF Normal probability density function 
003 % 
004 % CALL:  f = wnormpdf(x,m,v); 
005 % 
006 %        f = density function evaluated at x 
007 %        m = mean     (default 0) 
008 %        v = variance (default 1) 
009 %  
010 % Example:  
011 %   x = linspace(-3,3,200); 
012 %   p1 = wnormpdf(x,0,1); p2 = wnormpdf(x,.5,0.25); 
013 %   plot(x,p1,x,p2) 
014  
015  
016 % Tested on; Matlab 5.3 
017 % History: 
018 % revised pab 9Aug2003 
019 %  fixed a bug:  
020 % revised pab 24.10.2000 
021 %  - added comnsize, nargchk 
022 %  - added default values 
023 % added ms 15.06.2000 
024  
025 error(nargchk(1,3,nargin)) 
026 if nargin<2|isempty(m),  m=0;  end 
027 if nargin<3|isempty(v),  v=1;  end 
028  
029 [errorcode, x, m, v] = comnsize (x,m, v); 
030 if (errorcode > 0) 
031   error ('x, m and v must be of common size or scalar'); 
032 end 
033  
034 f=zeros(size(x)); 
035  
036 k = find (v>0); 
037 if any(k)     
038   f(k)=1./sqrt(2*pi*v(k)).*exp(-0.5*(x(k)-m(k)).^2./v(k)); 
039 end 
040  
041 k1 = find (v<=0); 
042 if any (k1) 
043   tmp=NaN; 
044   f(k1) = tmp(ones(size(k1))); 
045 end 
046  
047

Mathematical Statistics
Centre for Mathematical Sciences
Lund University with Lund Institute of Technology

Comments or corrections to the WAFO group


Generated on Thu 06-Oct-2005 02:21:16 for WAFO by m2html © 2003