decimate {oce} | R Documentation |
Smooth and decimate, or subsample, an oce object.
decimate(x, by=10, to, filter, debug=getOption("oceDebug"))
x |
an |
by |
an indication of the subsampling. If this is a single number, then
it indicates the spacing between elements of |
to |
Indices at which to subsample. If given, this over-rides
|
filter |
optional list of numbers representing a digital
filter to be applied to each variable in the |
debug |
a flag that turns on debugging. Set to 1 to get a moderate amount of debugging information, or to 2 to get more. |
Later on, other methods will be added, and
ctdDecimate
will be retired in favour of this, a more
general, function. The filtering is done with the
filter
function of the stats package.
An object of class
"oce"
that has been
subsampled appropriately.
Only a preliminary version of this function is provided in the
present package. It only works for objects of class echosounder
,
for which the decmation is done after applying a running median filter and
then a boxcar filter, each of length equal to the corresponding component
of by
.
Dan Kelley
Filter coefficients may be calculated using
makeFilter
. (Note that ctdDecimate
will be
retired when the present function gains equivalent functionality.)
library(oce) data(adp) plot(adp) adp.dec <- decimate(adp,by=2,filter=c(1/4,1/2,1/4)) plot(adp.dec)