WBETAPDF Beta probability density function CALL: f = wbetapdf(x,a,b); f = density function evaluated at x x = matrix a, b = distribution parameters The PDF is defined by: f = x^(a-1)*(1-x)^(b-1)/H(a,b) 0<= x <= 1, a>0, b>0 where H(a,b) is a normalization constant. Example: x = linspace(0,1,200); p1 = wbetapdf(x,1,1); p2 = wbetapdf(x,2,2); plot(x,p1,x,p2)
Check if all input arguments are either scalar or of common size. | |
Beta function. | |
Display message and abort function. | |
Not-a-Number. |
Beta Rayleigh PDF of wave heigth | |
Inverse of the Beta distribution function | |
Snedecor's F probability density function |
001 function f = wbetapdf(x,a,b) 002 %WBETAPDF Beta probability density function 003 % 004 % CALL: f = wbetapdf(x,a,b); 005 % 006 % f = density function evaluated at x 007 % x = matrix 008 % a, b = distribution parameters 009 % 010 % The PDF is defined by: 011 % 012 % f = x^(a-1)*(1-x)^(b-1)/H(a,b) 0<= x <= 1, a>0, b>0 013 % 014 % where H(a,b) is a normalization constant. 015 % Example: 016 % x = linspace(0,1,200); 017 % p1 = wbetapdf(x,1,1); p2 = wbetapdf(x,2,2); 018 % plot(x,p1,x,p2) 019 020 021 % tested on matlab 5.3 022 %History: 023 %revised pab 29.10.2000 024 % adapted from stixbox 025 % -added nargchk, comnsize 026 % Anders Holtsberg, 18-11-93 027 % Copyright (c) Anders Holtsberg 028 029 030 031 032 error(nargchk(3,3,nargin)) 033 [errorcode x,a,b] = comnsize(x,a,b); 034 if errorcode>0, 035 error('x, a and b must be of common size or scalar'); 036 end 037 038 f = zeros(size(x)); 039 040 ok = (a>0 & b>0); 041 042 k = find(x>=0&x<=1 & ok); 043 if any(k) 044 f(k) = x(k).^(a(k)-1) .* (1-x(k)).^(b(k)-1) ./ beta(a(k),b(k)); 045 end 046 047 048 049 050 k=find(~ok); 051 if (any(k)), 052 F(k)=NaN; 053 end 054
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