[ncl-talk] detrend not working right and calculate_monthly_values

[Ipshita Majhi]

Dear NCL,

I have been working on making a plot with correlation between detrended
data (snow cover extent) and I had first
used CDO to convert weekly data to monthly data. In the process the lat and
lon cordinates became y and x.
It works fine if till I reorder it. But it is not calculating dtrend
correctly, all the values are fill values.

I worked on using calculate_monthly_values to see if I could use it convert
weekly to monthly in NCL and I could not use it. I would be grateful for
any input

Here is the code I am using

;============================================
; set up parameters
;============================================

;This is extracting latitude of Western Europe
;Reading in the data
a=addfile("~/Documents/NCL_files/Snow_cover_IMS/NCL_codes/sce_mon_mean.nc","r")
; open output netCDF file
b=addfile("~/Documents/NCL_files/Snow_cover_IMS/
nhsce_v01r01_19661004_20140602.nc","r")

;Extracting  snow cover extent (sce) from respective data files

sce=byte2flt(a->sce)

sce at _FillValue = 9.9621e+36

lat=b->latitude
lon=b->longitude

sce at lat2d=lat
sce at lon2d=lon

;==============================================
;Reading in JJAS rainfall

JJAS_1871_2012
=asciiread("~/Documents/NCL_files/SST/Monthly/jjas_1871_2012.txt",(/142,1/),"float")

;Extracting JJAS for 1967 to 2012

JJAS_1967_2012=JJAS_1871_2012(96:141,0)

;============================================
;Extracting monthly data for sce

Jan_sce = new((/46,88,88/),float)

Jan_sce at _FillValue = 9.9621e+36

Jan_sce at lat2d=lat
Jan_sce at lon2d=lon

;==========================================

do nyr=0,551,12

Jan_sce(nyr/12,:,:) =sce(nyr,:,:)

end do

Jan_reorder=Jan_sce(y|:,x|:,time|:)

Jan_dt=dtrend(Jan_reorder,False)


Jan_reorder at _FillValue = 9.9621e+36

corr_jan=escorc(Jan_dt,JJAS_1967_2012)
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