percentiles: Percentile Rank and Cumulative Distribution Functions
Description
px returns the percentile ranks and fx the cumulative frequencies for each score point in a frequency distribution.
Usage
px(x,y)
fx(x)
Arguments
x
two-column matrix of class freqtab, where column 1 specifies the score scale and column 2 the frequencies for each score point. For px, x can also be a vector of s
y
optional frequency distribution of class freqtab (see details)
Value
px returns a vector of percentile ranks, and fx a vector of cumulative frequencies.
Details
px can be used to find the percentile ranks for a distribution of scores. When x is a frequency table and y is missing, the X distribution is used. If a frequency table is supplied for y, the percentile ranks are found for each score from x in the Y distribution. In this latter case x can either be a frequency table or simply a vector of scores.