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Function Reference: chi2pdf

statistics: y = chi2pdf (x, df)

Chi-squared probability density function (PDF).

For each element of x, compute the probability density function (PDF) of the chi-squared distribution with df degrees of freedom. The size of y is the common size of x and df. A scalar input functions as a constant matrix of the same size as the other inputs.

Further information about the chi-squared distribution can be found at https://en.wikipedia.org/wiki/Chi-squared_distribution

See also: chi2cdf, chi2pdf, chi2rnd, chi2stat

Source Code: chi2pdf

Example: 1

  

 ## Plot various PDFs from the chi-squared distribution
 x = 0:0.01:8;
 y1 = chi2pdf (x, 1);
 y2 = chi2pdf (x, 2);
 y3 = chi2pdf (x, 3);
 y4 = chi2pdf (x, 4);
 y5 = chi2pdf (x, 6);
 y6 = chi2pdf (x, 9);
 plot (x, y1, "-b", x, y2, "-g", x, y3, "-r", ...
       x, y4, "-c", x, y5, "-m", x, y6, "-y")
 grid on
 xlim ([0, 8])
 ylim ([0, 0.5])
 legend ({"df = 1", "df = 2", "df = 3", ...
          "df = 4", "df = 6", "df = 9"}, "location", "northeast")
 title ("Chi-squared PDF")
 xlabel ("values in x")
 ylabel ("density")
plotted figure