equate (version 2.0-3)

px: Percentile Ranks and Cumulativie Frequencies

Description

These functions compute percentile ranks and cumulative frequency distributions for frequency tables.

Usage

## S3 method for class 'default':
px(x, y, ys, ...)
## S3 method for class 'freqtab':
px(x, margin = 1, y, ymargin = 1, ...)
## S3 method for class 'default':
fx(x, ...)
## S3 method for class 'freqtab':
fx(x, margin = 1, ...)

Arguments

x

either a vector of counts, or an object of class freqtab from which counts will be taken.

y

an object of class freqtab when x is as well, otherwise, a vector or data.frame of counts. See below for details.

ys

vector specifying the y score scale, when it is not contained in the first column of y. If y can be converted to a data.frame, it is assumed to be univariate with the first column containing the score sc

margin, ymargin

integers specifying the margins for which frequencies or percentile ranks will be returned. margin applies to x and ymargin to y.

...

further arguments passed to or from other methods.

Value

• A vector is returned containing either percentile ranks or cumulative frequencies with length equal to length(x).

Details

These functions compute percentile ranks and cumulative frequencies for a univariate distribution, and percentile ranks from one univariate distribution (x) corresponding to score values in another (y).

See Also

freqtab

Examples

x <- as.freqtab(ACTmath[, 1:2], drop = TRUE)
y <- as.freqtab(ACTmath[, c(1, 3)], drop = TRUE)

# Percentile ranks for the x scale
round(px(x), 3)

# Percentile ranks in y for x each score
round(px(x, y = y), 3)

# Cumulative frequency distribution for x
round(fx(x), 3)