Generic Person - 6 months ago 26

R Question

I have a

`data.frame`

Is there a way of doing this without looping over the lines in the dataframe?

edit: this is for OHLC data, and so the high and low column should contain the highest and lowest element between a and b on the same line, and not among the whole columns. sorry if this is badly worded.

Answer

Sounds like you're looking for `pmax`

and `pmin`

("parallel" max/min):

```
Extremes package:base R Documentation
Maxima and Minima
Description:
Returns the (parallel) maxima and minima of the input values.
Usage:
max(..., na.rm = FALSE)
min(..., na.rm = FALSE)
pmax(..., na.rm = FALSE)
pmin(..., na.rm = FALSE)
pmax.int(..., na.rm = FALSE)
pmin.int(..., na.rm = FALSE)
Arguments:
...: numeric or character arguments (see Note).
na.rm: a logical indicating whether missing values should be
removed.
Details:
‘pmax’ and ‘pmin’ take one or more vectors (or matrices) as
arguments and return a single vector giving the ‘parallel’ maxima
(or minima) of the vectors. The first element of the result is
the maximum (minimum) of the first elements of all the arguments,
the second element of the result is the maximum (minimum) of the
second elements of all the arguments and so on. Shorter inputs
are recycled if necessary. ‘attributes’ (such as ‘names’ or
‘dim’) are transferred from the first argument (if applicable).
```