[ncl-talk] Function return
Dennis Shea
shea at ucar.edu
Sat Oct 14 15:26:01 MDT 2017
I just posted something to the original thread:
[ncl-talk] Question regarding cylindrical coordinate transformation using
NCL
It may be of some interest.
D
On Sat, Oct 14, 2017 at 2:36 PM, Prashanth Bhalachandran <
prashanth.bhalachandran at gmail.com> wrote:
> Alan,
> I give the filename and time as an input argument. The code now works
> where I define every other array except for the wnout array (the return
> from the function). The whole code is pasted here. The filename and time
> actually come from my shell script. But for debugging, I am giving it as an
> input argument. You were right in that wnout array does not need any prior
> definition. But the rest of them do, it seems.
>
> ncl 'filename = "20141009.nc"' 'time=24' varcalc.ncl
> Copyright (C) 1995-2017 - All Rights Reserved
> University Corporation for Atmospheric Research
> NCAR Command Language Version 6.4.0
> The use of this software is governed by a License Agreement.
> See http://www.ncl.ucar.edu/ for more details.
>
> Variable: wnout
> Type: list <fifo>
> Total items: 2
>
>
> ;;;;;;;;;;;;;;;;;;;;;;;; varcalc.ncl ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
>
>
> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"
> load "/scratch/lustreD/s/sbhalach/DATA/func_center.ncl"
> load "/scratch/lustreD/s/sbhalach/DATA/func_rtheta.ncl"
>
> a = addfile(filename,"r")
> u10 = a->u10
> v10 = a->v10
> slp = a->slp
>
> ;;;;;;;;;;;;;;;;; Constants ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
>
> R = 6371
> d2r = atan(1.0)/45; Equivalent of pi/180 - 0.01745329
> r2d = 1.0/d2r
> toknots = 1.94384
> pi = 3.14159
>
> ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
>
> latvals = new((/801/),float,1e+30)
> lonvals = new((/810/),float,1e+30)
> speed = new((/801,810/),float,1e+30)
> var01 = new((/251,73/),float,1e+30)
> var0 = new((/251/),float,1e+30)
>
>
> ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
>
> slpsub = slp(time,0,:,:) ; X is now a 2D array
> speed(:,:) = wind_speed(u10(time,0,:,:),v10(time,0,:,:)) * toknots
> latvals(:) = u10&lat(0:800)
> lonvals(:) = u10&lon(0:809)
>
> coord = center_find(speed(:,:),slpsub)
> lat1 = coord[0]
> lon1 = coord[1]
>
> wnout = wn01(latvals,lonvals,lat1,lon1,speed)
> var0 = wnout[0]
> var1 = wnout[1]
>
>
> ;;;;;;;;;;;;;;;;;;;;; FUNCTION (func_rtheta.ncl)
> ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
>
>
> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"
> load "/scratch/lustreD/s/sbhalach/DATA/func_center.ncl"
>
>
> undef("wn01")
>
> function wn01(latvals:float,lonvals:float,lat1:float,lon1:float,
> var:float)
> local R,d2r,r2d,toknots,pi,delr,Xi,Yi,xo,yo,nearxo,nearyo,ovar,
> var01,var0,c1,b1,orad,otha,arr,a1,a2,a3,a4,a5,a6,a7,a8,a9,r,weights
>
> begin
>
> R = 6371
> d2r = atan(1.0)/45; Equivalent of pi/180 or 0.01745329
> r2d = 1.0/d2r
> toknots = 1.94384
> pi = 3.14159
> delr = 12
>
> Xi = new((/810/),float,1e+30)
> Yi = new((/801/),float,1e+30)
> ovar = new((/251,73/),float,1e+30)
> var01 = new((/251,73/),float,1e+30)
> var0 = new((/251/),float,1e+30)
> c1 = new((/251/),float,1e+30)
> b1 = new((/251/),float,1e+30)
> orad = ispan(0,1000,delr)
> otha = fspan(0,6.283185,73)
> arr = new((/3,3/),float,1e+30)
>
> Xi(:) = R *cos(lat1*d2r)*(lonvals(:)-lon1) * d2r
> Yi(:) = R *(latvals(:)-lat1) * d2r
>
>
> do radius=0,250,1
> do theta=0,72,1
>
> xo = (radius*delr)*cos((theta*5)*d2r) ; reference points
> yo = (radius*delr)*sin((theta*5)*d2r) ; reference points
>
>
> nearxo = ind_nearest_coord (xo, Xi(:), 0) ;Find the index of the
> bounds
> nearyo = ind_nearest_coord (yo, Yi(:), 0)
>
> if(nearxo .eq. 0 .or. nearxo .eq. 809 .or. nearyo .eq. 0 .or. nearyo
> .eq. 800) then
> ovar(radius,theta) = var(nearyo,nearxo)
>
> else
> a1 = var(nearyo+1,nearxo+1)
> a2 = var(nearyo+1,nearxo)
> a3 = var(nearyo-1,nearxo-1)
> a4 = var(nearyo,nearxo+1)
> a5 = var(nearyo,nearxo)
> a6 = var(nearyo,nearxo-1)
> a7 = var(nearyo-1,nearxo+1)
> a8 = var(nearyo-1,nearxo)
> a9 = var(nearyo-1,nearxo-1)
>
> arr = (/ (/a1,a2,a3/), (/a4,a5,a6/), (/a7,a8,a9/)/) ; Written as nD
> arrays for visual clarity of neighbors
>
> weights = (/ (/0.0625,0.0625,0.0625/), (/0.0625,0.5,0.0625/),
> (/0.0625,0.0625,0.0625/)/)
> ovar(radius,theta) = dim_avg_wgt(ndtooned(arr),ndtooned(weights),1)
>
> ; Give 50% weight to the nearest location and distribute the other 50%
> equally amongst the neighbours
> end if
>
> end do ; Loop over every radius and theta
> end do ; End of r-theta loop
>
> do r=0,250,1
> var0(r) = 1/(2*pi)*simpeq(ovar(r,:),5.0*d2r)
> c1(r) = 1/(2*pi)*simpeq(ovar(r,:)*cos(otha),5.0*d2r)
> b1(r) = 1/(2*pi)*simpeq(ovar(r,:)*sin(otha),5.0*d2r)
> var01(r,:) = var0(r) + (c1(r)*cos(otha)) + (b1(r)*sin(otha))
> end do
>
>
> return([/var0,var01/])
> end
>
>
>
>
>
> On Oct 14, 2017, at 1:27 PM, Alan Brammer <abrammer at albany.edu> wrote:
>
> Would probably be best to attach varcalc.ncl so we can see the whole
> script.
>
> The edited code I sent back to you should not create those errors *if
> you have defined time somewhere*. Otherwise there will have been an
> initial error saying that time was not defined, which then cascades down
> the code. Previously, the code will have continued but with the empty
> arrays but doing effectively nothing.
>
> Always start with the first error.
>
>
>
> On Sat, Oct 14, 2017 at 4:13 PM, Prashanth Bhalachandran <
> prashanth.bhalachandran at gmail.com> wrote:
>
>> Dear Alan,
>> Unfortunately, I get a series of fatal errors if I don’t define them
>> apriori.
>>
>> fatal:Undefined identifier: (speed) is undefined, can't continue
>> fatal:["Execute.c":8640]:Execute: Error occurred at or near line 32 in
>> file varcalc.ncl
>>
>> fatal:Undefined identifier: (latvals) is undefined, can't continue
>> fatal:["Execute.c":8640]:Execute: Error occurred at or near line 33 in
>> file varcalc.ncl
>>
>> fatal:Undefined identifier: (lonvals) is undefined, can't continue
>> fatal:["Execute.c":8640]:Execute: Error occurred at or near line 34 in
>> file varcalc.ncl
>>
>> fatal:Undefined identifier: (speed) is undefined, can't continue
>> fatal:["Execute.c":8640]:Execute: Error occurred at or near line 36 in
>> file varcalc.ncl
>>
>> fatal:Undefined identifier: (coord) is undefined, can't continue
>> fatal:["Execute.c":8640]:Execute: Error occurred at or near line 37 in
>> file varcalc.ncl
>>
>> fatal:Undefined identifier: (coord) is undefined, can't continue
>> fatal:["Execute.c":8640]:Execute: Error occurred at or near line 38 in
>> file varcalc.ncl
>>
>> fatal:Variable (latvals) is undefined
>> fatal:["Execute.c":8640]:Execute: Error occurred at or near line 42 in
>> file varcalc.ncl
>>
>> fatal:Undefined identifier: (wnout) is undefined, can't continue
>> fatal:["Execute.c":8640]:Execute: Error occurred at or near line 43 in
>> file varcalc.ncl
>>
>> fatal:Undefined identifier: (wnout) is undefined, can't continue
>> fatal:["Execute.c":8640]:Execute: Error occurred at or near line 44 in
>> file varcalc.ncl
>>
>> fatal:Variable (var0) is undefined
>> fatal:["Execute.c":8640]:Execute: Error occurred at or near line 45 in
>> file varcalc.ncl
>>
>> fatal:Variable (var1) is undefined
>> fatal:["Execute.c":8640]:Execute: Error occurred at or near line 46 in
>> file varcalc.ncl
>>
>>
>> On Oct 14, 2017, at 12:44 PM, Alan Brammer <abrammer at albany.edu> wrote:
>>
>> > I don’t know what my dimensions of wnout will be. Will it be a
>> 251x251x73 array?
>>
>> It will
>> be a list, there won't be array dimensions. You do not need to define
>> wnout before hand.
>> likewise, you do not need to define var0 or var1 before hand.
>>
>> e.g.
>>
>>
>> a = addfile(filename,"r")
>> u10 = a->u10
>> v10 = a->v10
>> slp = a->slp
>>
>> ;;;;;;;;;;;;;;;;; Constants ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
>>
>> R = 6371
>> d2r = atan(1.0)/45; Equivalent of pi/180 - 0.01745329
>> r2d = 1.0/d2r
>> toknots = 1.94384
>> pi = 3.14159
>>
>> ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
>>
>> ;; this section wasn't really needed
>>
>> ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
>>
>> slpsub = slp(time,0,:,:) ; X is now a 2D array
>> speed = wind_speed(u10(time,0,:,:),v10(time,0,:,:)) * toknots
>> latvals = u10&lat(0:800)
>> lonvals = u10&lon(0:809)
>>
>> coord = center_find(speed(:,:),slpsub)
>> lat1 = coord[0]
>> lon1 = coord[1]
>>
>> ;;;;;;;;;;;;;; Find all variables here and store into allvars ;;;;;;;
>>
>> wnout = wn01(latvals,lonvals,lat1,lon1,speed)
>> var0 = wnout[0]
>> var1 = wnout[1]
>>
>> printVarSummary(var0)
>> printVarSummary(var1)
>>
>> ;;;;;;;;;;;;;;;;;;;;;; Write to a netcdf file ;;;;;;;;;;;;;;;;;;
>>
>> ;;;; I do not think the lines that were here will work.
>>
>> On Sat, Oct 14, 2017 at 10:26 AM, Prashanth Bhalachandran <
>> prashanth.bhalachandran at gmail.com> wrote:
>>
>>> Dear Marston,
>>> Thank you for your response. I will ensure that the missing values are
>>> the default ones from NCL. I hope my attaching the code will give you a
>>> little more context.
>>>
>>> My concern is this : If I am returning two arrays var0 and var01
>>> (please see the red highlighted portions for array dimensions), how will I
>>> receive it in the main wrapper script?
>>>
>>> That is, if my var0 dimension is : (/251/) and my var01 dimension is
>>> (/251,73/), and I return the variable from the function using
>>> return([/var0,var01/]), when I collect it in the wrapper script using
>>> wnout = wn01(latvals,lonvals,lat1,lon1,speed),
>>>
>>> I don’t know what my dimensions of wnout will be. Will it be a
>>> 251x251x73 array? I do know that I want to extract it as:
>>> var0 = wnout[0]
>>> var1 = wnout[1]
>>>
>>>
>>> *CODE*
>>>
>>> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"
>>> load "/scratch/lustreD/s/sbhalach/DATA/func_center.ncl"
>>> load "/scratch/lustreD/s/sbhalach/DATA/func_rtheta.ncl"
>>>
>>> a = addfile(filename,"r")
>>> u10 = a->u10
>>> v10 = a->v10
>>> slp = a->slp
>>>
>>> ;;;;;;;;;;;;;;;;; Constants ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
>>>
>>> R = 6371
>>> d2r = atan(1.0)/45; Equivalent of pi/180 - 0.01745329
>>> r2d = 1.0/d2r
>>> toknots = 1.94384
>>> pi = 3.14159
>>>
>>> ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
>>>
>>> latvals = new((/801/),float,1e+30)
>>> lonvals = new((/810/),float,1e+30)
>>> speed = new((/801,810/),float,1e+30)
>>> var01 = new((/251,73/),float,1e+30)
>>> var0 = new((/251/),float,1e+30)
>>>
>>>
>>> ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
>>>
>>> slpsub = slp(time,0,:,:) ; X is now a 2D array
>>> speed(:,:) = wind_speed(u10(time,0,:,:),v10(time,0,:,:)) * toknots
>>> latvals(:) = u10&lat(0:800)
>>> lonvals(:) = u10&lon(0:809)
>>>
>>> coord = center_find(speed(:,:),slpsub)
>>> lat1 = coord[0]
>>> lon1 = coord[1]
>>>
>>> ;;;;;;;;;;;;;; Find all variables here and store into allvars ;;;;;;;
>>>
>>> wnout = wn01(latvals,lonvals,lat1,lon1,speed)
>>> var0 = wnout[0]
>>> var1 = wnout[1]
>>>
>>> ;;;;;;;;;;;;;;;;;;;;;; Write to a netcdf file ;;;;;;;;;;;;;;;;;;
>>>
>>> system("rm -f $f1_$f2.nc")
>>> ncdf = addfile("$f1_$f2.nc","c")
>>> ncdf->allvars = allvars
>>> ncdf->yymmdd = $f1
>>> ncdf->time = $f2
>>>
>>> -------------------------------------------------------------------
>>>
>>> *FUNCTION *
>>>
>>> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"
>>> load "/scratch/lustreD/s/sbhalach/DATA/func_center.ncl"
>>>
>>>
>>> undef("wn01")
>>>
>>> function wn01(latvals:float,lonvals:float,lat1:float,lon1:float,var:f
>>> loat)
>>> local R,d2r,r2d,toknots,pi,delr,Xi,Yi,xo,yo,nearxo,nearyo,ovar,var
>>> 01,var0,c1,b1,orad,otha,arr,a1,a2,a3,a4,a5,a6,a7,a8,a9,r,weights
>>>
>>> begin
>>>
>>> R = 6371
>>> d2r = atan(1.0)/45; Equivalent of pi/180 or 0.01745329
>>> r2d = 1.0/d2r
>>> toknots = 1.94384
>>> pi = 3.14159
>>> delr = 12
>>>
>>> Xi = new((/810/),float,1e+30)
>>> Yi = new((/801/),float,1e+30)
>>> ovar = new((/251,73/),float,1e+30)
>>> var01 = new((/251,73/),float,1e+30)
>>> var0 = new((/251/),float,1e+30)
>>> c1 = new((/251/),float,1e+30)
>>> b1 = new((/251/),float,1e+30)
>>> orad = ispan(0,1000,delr)
>>> otha = fspan(0,6.283185,73)
>>> arr = new((/3,3/),float,1e+30)
>>>
>>> Xi(:) = R *cos(lat1*d2r)*(lonvals(:)-lon1) * d2r
>>> Yi(:) = R *(latvals(:)-lat1) * d2r
>>>
>>> do radius=0,250,1
>>> do theta=0,72,1
>>>
>>> xo = (radius*delr)*cos((theta*5)*d2r) ; reference points
>>> yo = (radius*delr)*sin((theta*5)*d2r) ; reference points
>>>
>>> nearxo = ind_nearest_coord (xo, Xi(:), 0) ;Find the index of the
>>> bounds
>>> nearyo = ind_nearest_coord (yo, Yi(:), 0)
>>>
>>> if(nearxo .eq. 0 .or. nearxo .eq. 809 .or. nearyo .eq. 0 .or. nearyo
>>> .eq. 800) then
>>> ovar(radius,theta) = var(nearyo,nearxo)
>>>
>>> else
>>> a1 = var(nearyo+1,nearxo+1)
>>> a2 = var(nearyo+1,nearxo)
>>> a3 = var(nearyo-1,nearxo-1)
>>> a4 = var(nearyo,nearxo+1)
>>> a5 = var(nearyo,nearxo)
>>> a6 = var(nearyo,nearxo-1)
>>> a7 = var(nearyo-1,nearxo+1)
>>> a8 = var(nearyo-1,nearxo)
>>> a9 = var(nearyo-1,nearxo-1)
>>>
>>> arr = (/ (/a1,a2,a3/), (/a4,a5,a6/), (/a7,a8,a9/)/) ; Written as nD
>>> arrays for visual clarity of neighbors
>>>
>>> weights = (/ (/0.0625,0.0625,0.0625/), (/0.0625,0.5,0.0625/),
>>> (/0.0625,0.0625,0.0625/)/)
>>> ovar(radius,theta) = dim_avg_wgt(ndtooned(arr),ndtooned(weights),1)
>>>
>>>
>>> ; Give 50% weight to the nearest location and distribute the other 50%
>>> equally amongst the neighbours
>>> end if
>>>
>>> end do ; Loop over every radius and theta
>>> end do ; End of r-theta loop
>>>
>>> do r=0,250,1
>>> var0(r) = 1/(2*pi)*simpeq(ovar(r,:),5.0*d2r)
>>> ; Dimension (/251/)
>>> c1(r) = 1/(2*pi)*simpeq(ovar(r,:)*cos(otha),5.0*d2r)
>>> b1(r) = 1/(2*pi)*simpeq(ovar(r,:)*sin(otha),5.0*d2r)
>>> var01(r,:) = var0(r) + (c1(r)*cos(otha)) + (b1(r)*sin(otha)) ;
>>> Dimension (/251,73/)
>>> end do
>>> return([/var0,var01/])
>>>
>>> end
>>>
>>>
>>>
>>> On Oct 14, 2017, at 12:42 AM, Marston Johnston <shejo284 at gmail.com>
>>> wrote:
>>>
>>> There is an error in your code: var0 = new((/251/),float,1e+30
>>> As a preference, I always find it best to use the default FillValues
>>> when creating arrays. Read up on missing values/fillvalues on the NCL
>>> wedpage.
>>>
>>> There is nothing wrong with returning a list from a function, even if
>>> the dimensions are different. Why would the dimensions matter?
>>> This doesn’t seem to be your problem. You have not provided enough
>>> information about your code and variable information (printVarSumary) to
>>> give a definite answer.
>>> It seems you need to do some more debugging of your code yourself.
>>>
>>> When defining functions, it is good practice to set the define the
>>> intrinsic variables as “local” as well as using the “undef” function.
>>> Using the same name for the variables inside and outside the function,
>>> if you are indeed using a function that is properly designed, can mask a
>>> bug in your code.
>>>
>>> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>> Marston S. Ward, PhD
>>> Department of Earth Sciences
>>> University of Gothenburg, Sweden
>>> Email: marston.johnston at gu.se
>>> SkypeID: marston.johnston
>>> Phone: +46-31-7864901 <+46%2031%20786%2049%2001>
>>> Only the fruitful thing is true!
>>> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>>
>>>
>>> *From: *ncl-talk <ncl-talk-bounces at ucar.edu> on behalf of Prashanth
>>> Bhalachandran <prashanth.bhalachandran at gmail.com>
>>> *Date: *Saturday, 14 October 2017 at 03:57
>>> *To: *<ncl-talk at ucar.edu>
>>> *Subject: *Re: [ncl-talk] Function return
>>>
>>> Hello,
>>> I have a quick question regarding returning of arrays from functions.
>>>
>>> In my code, I have two arrays var0 and var01 that I want to return from
>>> my function. Their dimensionalities are as follows:
>>>
>>>
>>> var0 = new((/251/),float,1e+30
>>> var01 = new((/251,73/),float,1e+30)
>>>
>>>
>>> At present, I am trying to return this using the command :
>>>
>>> return([/var0,var01/]) ; Note that the dimensions of var0 and var1 are
>>> different.
>>>
>>>
>>> As a result, in my wrapper script, when I receive the variables, it is
>>> becoming a confusing task.
>>>
>>>
>>> wnout = wn01(latvals,lonvals,lat1,lon1,speed)
>>> var0 = wnout[0]
>>> var1 = wnout[1]
>>>
>>>
>>> The above return procedure is giving out an error since I don’t know
>>> how to define the dimensions of wnout. Is there any better way to return
>>> two arrays of varying dimensions in NCL?
>>>
>>>
>>> Thank you,
>>> Prashanth
>>> _______________________________________________ ncl-talk mailing list
>>> ncl-talk at ucar.edu List instructions, subscriber options, unsubscribe:
>>> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>>>
>>>
>>>
>>> _______________________________________________
>>> ncl-talk mailing list
>>> ncl-talk at ucar.edu
>>> List instructions, subscriber options, unsubscribe:
>>> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>>>
>>>
>>
>>
>
>
> _______________________________________________
> ncl-talk mailing list
> ncl-talk at ucar.edu
> List instructions, subscriber options, unsubscribe:
> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.ucar.edu/pipermail/ncl-talk/attachments/20171014/2acb0b50/attachment.html>
More information about the ncl-talk
mailing list