scr ipt to plot Fpdf.In probability theory and statistics, the F-distribution is a continuous probability distribution.It is also known as Snedecor s F distribution or the Fisher–Snedecor distribution (after R. A. Fisher and George W. Snedecor). The F-distribution arises frequently as the null distribution of a test statistic, most notably in the analysis of variance see F-test.-scr ipt to plot Fpdf.In probability theory and statistics, the F-distribution is a continuous probability distribution.It is also known as Snedecor s F distribution or the Fisher–Snedecor distribution (after R. A. Fisher and George W. Snedecor). The F-distribution arises frequently as the null distribution of a test statistic, most notably in the analysis of variance　see F-test.