[ncl-talk] ncl plot getting killed
Komal Shukla
komalshukla1992 at gmail.com
Tue Dec 4 06:06:55 MST 2018
Hi Mary
I was trying your suggested method--which is below
;---Read WRF character Times array off the files
wrf_times = f[:]->Times ; character array, ntime x character_length
;---Convert WRF string times to numeric times
times = wrf_times_c(wrf_times,0)
printVarSummary(times)
;---Convert numeric times to N x 6 array (0=year,1=month,...,5=seconds)
ymdhms = cd_calendar(times,0)
years = ymdhms(:,0)
months = ymdhms(:,1)
days = ymdhms(:,2)
hours = ymdhms(:,3)
Now you can grab all the hours between 16 and 21 and use this to subset
your array:
ihour = ind(hours.ge.16.and.hours.le.21)
and then use the "ihour" index array to subscript the variables:
Mpan_avg = dim_avg_n(aa[:]->$vars_to_avg(0)$(ihour,:,:,:),0)
do nv=1,nvars-1
Mpan_avg = Mpan_avg +
dim_avg_n(aa[:]->$vars_to_avg(nv)$(ihour,:,:,:),0)
end do
Kim
when i do this, it says, fatal:Undefined identifier: (wrf_times_c) is
undefined, can't continue, why is it? Any suggestion to correct.
On Fri, Nov 30, 2018 at 12:58 AM Mary Haley <haley at ucar.edu> wrote:
>
>
> Hi Komal,
>
> Glad it worked. We ask that people post all follow-up questions to
ncl-talk, so I've CC'ed ncl-talk here.
>
> As for your certain hour window question, this depends on what your
"time" array looks like. Are the files hourly, daily, 6-hourly, something
else?
>
> If your time array was length 24, where each index represented an hour:
>
> index 0 --> hour 0
> index 1 --> hour 1
> . . .
> index 16 --> hour 16
> ...
> index 21 --> hour 21
>
>
> then you could do something like this:
>
> ;---Average the first one and store to variable
> Mpan_avg = dim_avg_n(aa[:]->$vars_to_avg(0)$(16:21,:,:,:),0)
>
> ;---Loop thru rest of vars and sum their averages
> do nv=1,nvars-1
> Mpan_avg = Mpan_avg +
dim_avg_n(aa[:]->$vars_to_avg(nv)$(16:21,:,:,:),0)
> end do
>
> Note that I'm assuming your array is four-dimensional. If it is
three-dimensional, then you need to remove one of the colons:
>
> Mpan_avg = Mpan_avg + dim_avg_n(aa[:]->$vars_to_avg(nv)$(16:21,:,:),0)
>
> However, in general, it's not a good idea to hard code indexes in this
way.
>
> Instead, I recommend using wrf_times_c to convert your WRF Times
character array to numeric times, and then cd_calendar to convert from the
numeric times to an ntime x 6 array, where the 6 represents year, month,
day, hour, minute, second.
>
> For example:
>
> ;---Read WRF character Times array off the files
> wrf_times = f[:]->Times ; character array, ntime x character_length
> ;---Convert WRF string times to numeric times
> times = wrf_times_c(wrf_times,0)
> printVarSummary(times)
>
> ;---Convert numeric times to N x 6 array (0=year,1=month,...,5=seconds)
> ymdhms = cd_calendar(times,0)
> years = ymdhms(:,0)
> months = ymdhms(:,1)
> days = ymdhms(:,2)
> hours = ymdhms(:,3)
>
> Now you can grab all the hours between 16 and 21 and use this to subset
your array:
>
> ihour = ind(hours.ge.16.and.hours.le.21)
>
> and then use the "ihour" index array to subscript the variables:
>
> Mpan_avg = dim_avg_n(aa[:]->$vars_to_avg(0)$(ihour,:,:,:),0)
> do nv=1,nvars-1
> Mpan_avg = Mpan_avg +
dim_avg_n(aa[:]->$vars_to_avg(nv)$(ihour,:,:,:),0)
> end do
>
> --Mary
>
> On Thu, Nov 29, 2018 at 4:34 AM Komal Shukla <komalshukla1992 at gmail.com>
wrote:
>>
>> Mary,
>>
>> This worked just brilliant without killing the process(your modified
script below). What changed to be made in it, if we just need average of a
certain hour window (for example 16:00 -21:00 hours, considering 0 to be
first) instead of 24 hours?
>>
>> vars_to_avg = (/"no","no2","oli","csl","hc3","ket"/)
>> nvars = dimsizes(vars_to_avg)
>>
>> ;---Average the first one and store to variable
>> Mpan_avg = dim_avg_n(aa[:]->$vars_to_avg(0)$,0)
>>
>> ;---Loop thru rest of vars and sum their averages
>> do nv=1,nvars-1
>> Mpan_avg = Mpan_avg + dim_avg_n(aa[:]->$vars_to_avg(nv)$,0)
>> end do
>> Mpan_avg=Mpan_avg*1000
>> Mpan_avg2D=Mpan_avg(0,:,:)
>>
>>
>>
>> On Thu, Nov 29, 2018 at 4:34 PM Komal Shukla <komalshukla1992 at gmail.com>
wrote:
>>>
>>> Mary,
>>> It works just the right,4th option is most optimised. thanks!
>>>
>>>
>>>
>>>
>>> On Wed, Nov 28, 2018 at 8:49 PM Mary Haley <haley at ucar.edu> wrote:
>>>>
>>>> Hi Kim,
>>>>
>>>> You could be correct that this is a memory issue. Are you getting any
errors from NCL before it quits?
>>>>
>>>> You can save on memory by not creating so many local variables. Below
are four possible scenarios you can try:
>>>>
>>>> [1] You can delete a variable after you no longer need it, which will
free up some memory.
>>>>
>>>> no = aa[:]->no
>>>> no_avg=dim_avg_n(no,0)
>>>> delete(no)
>>>> no2 = aa[:]->no2
>>>> no2_avg=dim_avg_n(no2,0)
>>>> delete(no2)
>>>> oli = aa[:]->oli
>>>> oli_avg=dim_avg_n(oli,0)
>>>> delete(oli)
>>>>
>>>> [2] You can use [/.../] to delete several variables at once, if you
don't need to free them individually:
>>>>
>>>> no = aa[:]->no
>>>> no_avg=dim_avg_n(no,0)
>>>> no2 = aa[:]->no2
>>>> no2_avg=dim_avg_n(no2,0)
>>>> oli = aa[:]->oli
>>>> oli_avg=dim_avg_n(oli,0)
>>>> delete([/no,no2,oli/])
>>>>
>>>> [3] Even better, if there's no reason that variables like "no", "no2",
and "oli" need to exist, then there's no need to save them to a local
variable before taking the average:
>>>>
>>>> no_avg = dim_avg_n(aa[:]->no,0)
>>>> no2_avg= dim_avg_n(aa[:]->no2,0)
>>>> oli_avg = dim_avg_n(aa[:]->oli,0)
>>>>
>>>> [4] Since you are doing the same operation repeatedly, you can use a
do loop and save yourself some more memory.
>>>>
>>>> vars_to_avg = (/"no","no2","oli","csl","olt","xyl","ald","hc8",\
>>>> "hcho","ol2","tol","hc5","hc3","ket"/)
>>>> nvars = dimsizes(vars_to_avg)
>>>>
>>>> ;---Average the first one and store to variable
>>>> Mpan_avg = dim_avg_n(aa[:]->$vars_to_avg(0)$,0)
>>>>
>>>> ;---Loop thru rest of vars and sum their averages
>>>> do nv=1,nvars-1
>>>> Mpan_avg = Mpan_avg + dim_avg_n(aa[:]->$vars_to_avg(nv)$,0)
>>>> end do
>>>> Mpan_avg=Mpan_avg*1000
>>>> Mpan_avg2D=Mpan_avg(0,:,:)
>>>> . . .
>>>>
>>>> The above is not tested, so hopefully there are no syntax errors in it.
>>>>
>>>> --Mary
>>>>
>>>>
>>>> On Wed, Nov 28, 2018 at 2:49 AM Komal Shukla <komalshukla1992 at gmail.com>
wrote:
>>>>>
>>>>> Hi
>>>>>
>>>>> I am trying to add a variable from netcdf files, and make an average
plot. My scripts is mentioned below, but the process gets killed. Maybe
because of memory.
>>>>>
>>>>> Can you please suggest a "efficient" way of writing this? Please help.
>>>>>
>>>>> Script ----------
>>>>> begin
>>>>> a = addfile("../wrfout_d01_2012-05-01_00:00:00.nc","r")
>>>>>
>>>>> it = 0 ; first time step
>>>>> hgt = wrf_user_getvar(a,"HGT_M",it) ; Terrain elevation
>>>>> hgt at lat2d = wrf_user_getvar(a,"XLAT",it) ; latitude/longitude
>>>>> hgt at lon2d = wrf_user_getvar(a,"XLONG",it) ; required for plotting
>>>>>
>>>>> wks = gsn_open_wks("png","try1")
>>>>>
>>>>> FILES = systemfunc ("ls ../wrfout_d01_2012-05*") ; file paths
>>>>>
>>>>> numFILES = dimsizes(FILES)
>>>>> aa = addfiles (FILES+".nc", "r") ;add multiple files
>>>>> ;;;;;;;;;;;;
>>>>>
>>>>> no = aa[:]->no
>>>>> no_avg=dim_avg_n(no,0)
>>>>> no2 = aa[:]->no2
>>>>> no2_avg=dim_avg_n(no2,0)
>>>>> oli = aa[:]->oli
>>>>> oli_avg=dim_avg_n(oli,0)
>>>>> csl = aa[:]->csl
>>>>> csl_avg=dim_avg_n(csl,0)
>>>>> olt = aa[:]->olt
>>>>> olt_avg=dim_avg_n(olt,0)
>>>>> xyl = aa[:]->xyl
>>>>> xyl_avg=dim_avg_n(xyl,0)
>>>>> ald = aa[:]->ald
>>>>> ald_avg=dim_avg_n(ald,0)
>>>>> hc8 = aa[:]->hc8
>>>>> hc8_avg=dim_avg_n(hc8,0)
>>>>> hcho = aa[:]->hcho
>>>>> hcho_avg=dim_avg_n(hcho,0)
>>>>> ol2 = aa[:]->ol2
>>>>> ol2_avg=dim_avg_n(ol2,0)
>>>>> tol = aa[:]->tol
>>>>> tol_avg=dim_avg_n(tol,0)
>>>>> hc5= aa[:]->hc5
>>>>> hc5_avg=dim_avg_n(hc5,0)
>>>>> hc3= aa[:]->hc3
>>>>> hc3_avg=dim_avg_n(hc3,0)
>>>>> ket= aa[:]->ket
>>>>> ket_avg=dim_avg_n(ket,0)
>>>>>
>>>>>
Mpan_avg=no_avg+no2_avg+oli_avg+csl_avg+olt_avg+xyl_avg+ald_avg+hc8_avg+hcho_avg+ol2_avg+tol_avg+hc5_avg+hc3_avg+ket_avg
>>>>> Mpan_avg=Mpan_avg*1000
>>>>> Mpan_avg2D=Mpan_avg(0,:,:)
>>>>> Mpan_avg2D at lat2d = wrf_user_getvar(a,"XLAT",it) ; latitude/longitude
>>>>> Mpan_avg2D at lon2d = wrf_user_getvar(a,"XLONG",it) ; required for
plotting
>>>>> --some plotting options here--
>>>>> contour = gsn_csm_contour_map(wks,Mpan_avg2D,res)
>>>>> draw(contour)
>>>>> frame(wks)
>>>>>
>>>>> Thanks
>>>>> Kim
>>>>> _______________________________________________
>>>>> ncl-talk mailing list
>>>>> ncl-talk at ucar.edu
>>>>> List instructions, subscriber options, unsubscribe:
>>>>> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
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