Statistics: chi2inv

### Function Reference: `chi2inv`

statistics: x = chi2inv (p, df)

Inverse of the chi-squared cumulative distribution function (iCDF).

For each element of p, compute the quantile (the inverse of the CDF) of the chi-squared distribution with df degrees of freedom. The size of x is the common size of p 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: chi2inv

### Example: 1

     ## Plot various iCDFs from the chi-squared distribution
     p = 0.001:0.001:0.999;
     x1 = chi2inv (p, 1);
     x2 = chi2inv (p, 2);
     x3 = chi2inv (p, 3);
     x4 = chi2inv (p, 4);
     x5 = chi2inv (p, 6);
     x6 = chi2inv (p, 9);
     plot (p, x1, "-b", p, x2, "-g", p, x3, "-r", ...
           p, x4, "-c", p, x5, "-m", p, x6, "-y")
     grid on
     ylim ([0, 8])
     legend ({"df = 1", "df = 2", "df = 3", ...
              "df = 4", "df = 6", "df = 9"}, "location", "northwest")
     title ("Chi-squared iCDF")
     xlabel ("probability")
     ylabel ("values in x")