
dtrend_leftdim
Estimates and removes the least squares linear trend of the leftmost dimension from all grid points and retains metadata.
Prototype
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl" ; This library is automatically loaded ; from NCL V6.2.0 onward. ; No need for user to explicitly load. function dtrend_leftdim ( y : numeric, return_info [1] : logical ) return_val [dimsizes(y)] : numeric
Arguments
yAn array with one or more dimensions, nominally, (time), (time,lat,lon), etc.
return_infoA logical scalar controlling whether attributes corresponding to the y-intercept and slope are attached to return_val. True = attributes returned. False = no attributes returned.
Return value
An array of the same size as y. Double if y is double, float
otherwise.
Two attributes (slope and y_intercept) may be attached to return_val if
return_info = True. These attributes will be one-dimensional arrays if
y is one-dimensional. If y is multi-dimensional, the
attributes will be the same size as y .
Double if return_val is double,
float otherwise.
You access the attributes through the @ operator:
print(return_val@slope) print(return_val@y_intercept)
Description
This is a utility function that behaves like dtrend/dtrend_n, except it retains metadata.
Before version 5.2.0, this function (a) reordered the input array, y; (b) used dtrend to detrend; and, (c) returned to the original dimension order. For version 5.2.0 and later, this function uses dtrend_n to avoid having to reorder the data.
See Also
dtrend_n, dtrend, dtrend_msg_n, dtrend_msg
Examples
Example 1
Let y be three-dimensional array with nominal dimensions (time, lat, lon).
yDtrend = dtrend_leftdim(y,False)The return array will have the same ordering and will retain metadata.