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Function Reference: fcdf

statistics: p = fcdf (x, df1, df2)
statistics: p = fcdf (x, df1, df2, 'upper')

F-cumulative distribution function (CDF).

For each element of x, compute the cumulative distribution function (CDF) of the F-distribution with df1 and df2 degrees of freedom. The size of p is the common size of x, df1, and df2. A scalar input functions as a constant matrix of the same size as the other inputs.

p = fcdf (x, df1, df2, "upper") computes the upper tail probability of the F-distribution with df1 and df2 degrees of freedom, at the values in x.

Further information about the F-distribution can be found at https://en.wikipedia.org/wiki/F-distribution

See also: finv, fpdf, frnd, fstat

Source Code: fcdf

Example: 1

Plot various CDFs from the F distribution

 x = 0.01:0.01:4;
 p1 = fcdf (x, 1, 2);
 p2 = fcdf (x, 2, 1);
 p3 = fcdf (x, 5, 2);
 p4 = fcdf (x, 10, 1);
 p5 = fcdf (x, 100, 100);
 plot (x, p1, '-b', x, p2, '-g', x, p3, '-r', x, p4, '-c', x, p5, '-m')
 grid on
 legend ({'df1 = 1, df2 = 2', 'df1 = 2, df2 = 1', ...
          'df1 = 5, df2 = 2', 'df1 = 10, df2 = 1', ...
          'df1 = 100, df2 = 100'}, 'location', 'southeast')
 title ('F CDF')
 xlabel ('values in x')
 ylabel ('probability')
plotted figure