An Empirical Percentile Transformation (percentize) is similar to taking the rank of a variable. The difference is that it is simpler to compare and interpret the transformed variables.

This is helpful for comparing several variables in a heatmap (e.g.: heatmaply).

`percentize(x, ...)`

- x
a vector or a data.frame.

- ...
Currently ignored.

A vector (or data.frame) after ecdf was used on that vector. If x is a data.frame then only the numeric variables are transformed.

```
if (FALSE) {
x <- mtcars
x <- data.frame(x)
x$am <- factor(x$am)
x$vs <- factor(x$vs)
heatmaply(percentize(x))
x <- data.frame(a = 1:10, b = 11:20)
x[4:6, 1:2] <- NA
percentize(x)
percentize(x[, 1])
}
```