I am using
the method provided by Russ a couple of years ago
to compute percentile along time axis for gridded data
of sea ice
concentrations.
The resultant
Q-tiles are a bit of too scattered in the seasonal
varying ice zone. I have worked with Russ directly
during the shutdown – Thank
you, Russ, for your helpful suggestions.
looking into it in
more details, I am a bit of confused by
the behavior of function sortl which does not seem to
sort correctly in ldim at
each I,j grid cell in the sense that the largest value
should be sorted as the last.
It can be demonstrated by the following ferret output.
(I was using a much
earlier version but have reinstalled the latest per
Russ’s suggestion. The results are the same.)
Is this correct?
Thanks,
--- Peng
$ ferret
NOAA/PMEL TMAP
FERRET v7.44 (optimized)
Linux
3.10.0-957.1.3.el7.x86_64
64-bit - 12/07/18
4-Feb-19 14:01
yes? use
coads_climatology
yes? let
numpoints=`sst,return=lend`
!-> DEFINE
VARIABLE numpoints=12
yes? let
numlats=`sst,return=jend]`
!-> DEFINE
VARIABLE numlats=90
yes?
let/title="sorted indices"
sorted_by_time=sortl(sst[l=1:`numpoints`])
!-> DEFINE
VARIABLE/title="sorted indices"
sorted_by_time=sortl(sst[l=1:12])
yes? list
sst[i=90,j=45],sorted_by_time[i=90,j=45]
WARNING: Listed
variables have ambiguous coordinates on axes: T
DATA
SET:
/snfs1/users/gpeng/myFerret/fer_dsets/FerretDatasets-7.4/data/coads_climatology.cdf
LONGITUDE: 161W
LATITUDE:
1S
Column 1:
SST[T=01-JAN 00:45:31-DEC 06:34] is SEA
SURFACE TEMPERATURE (Deg C)
Column 2:
SORTED_BY_TIME[T=0.5:12.5] is sorted
indices
SST
SORTED_BY_TIME
L / 1: 26.82
1.00
L / 2: 26.99
2.00
L / 3: 27.47
12.00
L / 4: 27.83
11.00
L / 5: 27.96
9.00
L / 6:
28.22 8.00
L / 7: 27.96
3.00
L / 8: 27.42
10.00
L / 9: 27.33
4.00
L / 10: 27.55
5.00
L / 11: 27.22
7.00
L / 12: 27.02
6.00