Function Reference: hnpdf

statistics: y = hnpdf (x, mu, sigma)

Half-normal probability density function (PDF).

For each element of x, compute the probability density function (PDF) of the half-normal distribution with location parameter mu and scale parameter sigma. The size of y is the common size of x, mu, and sigma. A scalar input functions as a constant matrix of the same size as the other inputs.

The half-normal CDF is only defined for x >= mu.

Further information about the half-normal distribution can be found at https://en.wikipedia.org/wiki/Half-normal_distribution

See also: hncdf, hninv, hnrnd, hnfit, hnlike, hnstat

Source Code: hnpdf

Example: 1

  

 ## Plot various PDFs from the half-normal distribution
 x = 0:0.001:10;
 y1 = hnpdf (x, 0, 1);
 y2 = hnpdf (x, 0, 2);
 y3 = hnpdf (x, 0, 3);
 y4 = hnpdf (x, 0, 5);
 plot (x, y1, "-b", x, y2, "-g", x, y3, "-r", x, y4, "-c")
 grid on
 xlim ([0, 10])
 ylim ([0, 0.9])
 legend ({"μ = 0, σ = 1", "μ = 0, σ = 2", ...
          "μ = 0, σ = 3", "μ = 0, σ = 5"}, "location", "northeast")
 title ("Half-normal PDF")
 xlabel ("values in x")
 ylabel ("density")
plotted figure

Example: 2

  

 ## Plot half-normal against normal probability density function
 x = -5:0.001:5;
 y1 = hnpdf (x, 0, 1);
 y2 = normpdf (x);
 plot (x, y1, "-b", x, y2, "-g")
 grid on
 xlim ([-5, 5])
 ylim ([0, 0.9])
 legend ({"half-normal with μ = 0, σ = 1", ...
          "standart normal (μ = 0, σ = 1)"}, "location", "northeast")
 title ("Half-normal against standard normal PDF")
 xlabel ("values in x")
 ylabel ("density")
plotted figure