[R] Wrap to 360

[William Dunlap]

The key function is '%%' (remainder), but its result needs to be
tweaked at mulitplies of 360 because Matlab's definition of wrapTo360
is

lonWrapped = wrapTo360(lon) wraps angles in lon, in degrees, to the
interval [0 360] such that 0 maps to 0 and 360 maps to 360. (In
general, positive multiples of 360 map to 360 and negative multiples
of 360 map to zero.)

wrapTo360 <- function (lon)
{
    ret <- lon%%360
    ret[lon >= 360 & ret == 0] <- 360
    ret
}

As in:

> wrapTo360(c(-721,-720,-719,-361,-360,-359,-1,0,1,359,360,361,720,721))
 [1] 359   0   1 359   0   1 359   0   1 359 360   1 360   1


Bill Dunlap
TIBCO Software
wdunlap tibco.com


On Mon, Feb 13, 2017 at 8:44 AM, Peter Mills <peter.mills at strath.ac.uk> wrote:
> Hi
>
> Is there an equivalent for R of the Matlab function wrapTo360?
>
> Many thanks
> Peter
>
>
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