[ncl-talk] Replacement of data with a constant value

Dennis Shea shea at ucar.edu
Mon Jul 15 12:05:36 MDT 2019 

As noted in a previous ncl-talk question, the most important rule of data
processing is "look at your data".
This is user responsibility.

+++ ON THE HDF FILE
      *short *Optical_Depth_047_grid1km ( Orbits_grid1km, YDim_grid1km,
XDim_grid1km )
         coordinates :  GridLat_grid1km, GridLon_grid1km
         hdfeos_name :  Optical_Depth_047
         projection :   Sinusoidal

*        valid_range :  ( -100, 5000 )    ; these pertain to the "short"
numerical type         _FillValue :   -28672                ; type "short"*
         unit : none

*      add_offset :      0         scale_factor : 0.001*
         long_name :    AOD at 0.47 micron

+++ AFTER unpacking via *short2flt, the*

*V*ariable: x   <=== Optical_Depth_047_grid1km
Type:* float*
[SNIP]
  long_name : AOD at 0.47 micron
[snip]
  _FillValue : -28672              *<== these are now type float*

*  valid_range : ( -0.1,  5 )     <== these are now type float in the
unpacked range*

Some code to add to your script.

 f0   = *addfile*(diri+fili(0)+".he2", "r")   ;  .he2 causes NCL to add
lat/lon arrays
  x    = *short2flt*( f0->$vNam$   )   ; ( Orbits_grid1km, YDim_grid1km,
XDim_grid1km )

*printVarSummary*(x)
*printMinMax*(x,0)
print("=============================")
  nmsg = *num(ismissing*(x))
  ngood= *num*(*.not.ismissing*(x))
  npts = nmsg+ngood
  npc  = (ngood/*tofloat*(npts))*100
print("nmsg ="+nmsg)
print("ngood="+ngood)
print("npc (%)="+npc)
print("=============================")

; *****************************************************************
  nx   = num(x.ge. -0.1 .and. x.le.5.0)   ; values after unpacking
                                          ; within allowed range
print("nx="+nx+":  this should match ngood="+ngood) ; ie: there are no out
of range values
  X01  = where(x.ge. -0.1 .and. x.le.5.0, 1, 0)
printVarSummary(X01)
  n1n   = num(X01.eq.1)
  n1s   = sum(X01)
print("n1n="+n1n+"   n1s="+n1s)
print("=============================")

On Mon, Jul 15, 2019 at 10:27 AM Herb, Jason <jherb at albany.edu> wrote:

> Dennis,
>
>
> I have attempted to make the suggested changes and received even more
> errors despite creating an additional variable..... errors can be found
> below below. I have attached full code and the file that I am working with
> to get the plot.
>
>
>  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.
> (0)     nfil=1
> fatal:Number of dimensions on right hand side do not match number of
> dimension in left hand side
> fatal:["Execute.c":8640]:Execute: Error occurred at or near line 106 in
> file MCD19A2.Jason2.ncl
>
> fatal:syntax error: procedure bin_sum expects 7 arguments, got 8
> fatal:error at line 128 in file MCD19A2.Jason2.ncl
>
> fatal:Syntax Error in block, block not executed
> fatal:error at line 133 in file MCD19A2.Jason2.ncl
>
> (0)
> =====> Wall Clock Elapsed Time: Main Sum Loop: nlat=3600, mlon=7200: 0
> seconds <=====
>
> fatal:Variable (f) is undefined
> fatal:["Execute.c":8640]:Execute: Error occurred at or near line 151 in
> file MCD19A2.Jason2.ncl
>
> fatal:Variable (f) is undefined
> fatal:["Execute.c":8640]:Execute: Error occurred at or near line 157 in
> file MCD19A2.Jason2.ncl
>
> fatal:syntax error: procedure gsn_panel expects 4 arguments, got 3
> fatal:error at line 215 in file MCD19A2.Jason2.ncl
>
> fatal:Syntax Error in block, block not executed
> fatal:error at line 217 in file MCD19A2.Jason2.ncl
>
>
> ------------------------------
> *From:* Dennis Shea <shea at ucar.edu>
> *Sent:* Monday, July 15, 2019 11:18:35 AM
> *To:* Herb, Jason
> *Cc:* ncl-talk at ucar.edu
> *Subject:* Re: [ncl-talk] Replacement of data with a constant value
>
> *http://www.ncl.ucar.edu/Document/Functions/Built-in/where.shtml*
> <http://www.ncl.ucar.edu/Document/Functions/Built-in/where.shtml>
> *http://www.ncl.ucar.edu/Document/Functions/Built-in/num.shtml*
> <http://www.ncl.ucar.edu/Document/Functions/Built-in/num.shtml>
>
> I am not sure where you got the form you are using for '*where*'.
> In no example is there an 'x=1' style for any of the arguments.
>
> Also, given your description, I'm not sure that you want to use '*where'*
>
> x       = *short2flt*( f->$vNam$   )            ; ( Orbits_grid1km,
> YDim_grid1km, XDim_grid1km )
> nx     = *num*(x.gt.-100 .and. x.lt.5000)   ; #  of values bwtweem -100
> and 5000
> ===
>
> x01   = *where*(x.gt.-100 .and. x.lt.5000, 0, 1)                  ;
> create an array of 0 and 1
> n1     = *num*(x.eq.1)                              ; also: *sum*(x)
>
> On Mon, Jul 15, 2019 at 8:24 AM Herb, Jason via ncl-talk <
> ncl-talk at ucar.edu> wrote:
>
> Hello,
>
>
> I am working with the MCD19A2 data. In order to see the data extent for
> any given time period, 1 day, 1 month, 1 year, or any selected time period
> we need to assess.I have a binning code to add the points, however the
> points that are being added are the original AOD values in the hdf files.
> In order to do this I am attempting to replace all data points in the hdf
> file to " 1 " if there is data that is within the range flag of the data
> file. I have attempted to use the "where" function to make these
> replacements however I keep getting error bugs coming up. The portion of
> the script can be found below.
>
>
> Script error messages
>
> fatal:syntax error: line 120 in file MCD19A2.Jason1.ncl before or near =
>      x1 = where(x.gt.-100 .and. x.lt.5000, x =
> ---------------------------------------------^
>
> fatal:Syntax Error in block, block not executed
> fatal:error at line 136 in file MCD19A2.Jason1.ncl
>
> (0)
> =====> Wall Clock Elapsed Time: Main Sum Loop: nlat=3600, mlon=7200: 0
> seconds <=====
>
> fatal:Variable (f) is undefined
> fatal:["Execute.c":8640]:Execute: Error occurred at or near line 154 in
> file MCD19A2.Jason1.ncl
>
> fatal:Variable (f) is undefined
> fatal:["Execute.c":8640]:Execute: Error occurred at or near line 159 in
> file MCD19A2.Jason1.ncl
>
> warning:ContourPlotInitialize: no valid values in scalar field;
> ContourPlot not possible:[errno=1101]
> warning:ContourPlotInitialize: no valid values in scalar field;
> ContourPlot not possible:[errno=1101]
>
>
> Script coding
>  tStrt = systemfunc("date")         ; time the loop (wall clock)
>
>   do nf=0,nfil-1                     ; loop over all files
>      print(nf+"   "+fili(nf))
>      f       = addfile(diri+fili(nf)+".he2", "r")   ;  .he2 causes NCL to
> add lat/lon arrays
>                                      ; read data
>      lat2d   = f->GridLat_grid1km
>      lon2d   = f->GridLon_grid1km
>
>      x       = short2flt( f->$vNam$   )   ; ( Orbits_grid1km,
> YDim_grid1km, XDim_grid1km )
> ;*************** attmeping to change any AOD data other then N/A to 1 to
> count up
>      x1 = where(x.gt.-100 .and. x.lt.5000, x = 1)
>      delete(  x  )
>      x = x1
>
> Thank you for you time
>
> Jason
>
>
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