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20010705: GRD commands

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  • Subject: 20010705: GRD commands
  • Date: Thu, 05 Jul 2001 17:30:31 -0600
>From:  Don Murray <address@hidden>
>Organization:  Unidata/UCAR
>Keywords:  200107052225.f65MPi119715 McIDAS GRDCOPY

Don,e

>Is there a way to do a GRDCOPY on the ETA grids and specify only the 211
>grids (63 rows x 93 cols)?  I want to make a subset that I can play
>with here next week, once I don't have a network connection.  If not,
>I'll just ask for a smaller dataset.

There is not really a way to copy just the 211 grids, at least not easily.
One can specify the GPRO=LAMB keyword, but will get all of the other LAMBert
Conformal projections also.

I just did a quick GRDLIST of RTGRIDS/ETA from papagayo.unl.edu and
see that at least the first 100 grids are all 211 ones:

GRDLIST RTGRIDS/ETA FORM=ALL GPRO=LAMB NUM=100
Dataset position 6      Directory Title= ALL  00Z ETA 0  HR<=VT<=24 HR
PAR    LEVEL       DAY        TIME    SRC FHOUR     FDAY       FTIME  GRID  PRO
---- --------- ------------ -------- ---- ----- ------------ -------- ----- ----
W     100 MB   05 JUL 01186 00:00:00  ETA     0 05 JUL 01186 00:00:00     1 LAMB
Total pts=  6045 Num rows=  65  Num columns=  93    received:  2001186 020448Z
Vertical velocity
GRIB ID numbers: Geographic =211; PAR = 39; Model ID = 84; Level type =100
Units of gridded variable are PAPS Scale of variable is:   2
Lambert Conformal Tangent Cone Projection
Row num of pole= -113.34  Col num of pole=   53.00  Col spacing (m)= 81270.0
Standard Latitudes=   25.00     25.00   Standard Longitude=   95.00
PAR    LEVEL       DAY        TIME    SRC FHOUR     FDAY       FTIME  GRID  PRO
---- --------- ------------ -------- ---- ----- ------------ -------- ----- ----
W     200 MB   05 JUL 01186 00:00:00  ETA     0 05 JUL 01186 00:00:00     2 LAMB
Total pts=  6045 Num rows=  65  Num columns=  93    received:  2001186 020448Z
Vertical velocity
GRIB ID numbers: Geographic =211; PAR = 39; Model ID = 84; Level type =100
Units of gridded variable are PAPS Scale of variable is:   2
Lambert Conformal Tangent Cone Projection
Row num of pole= -113.34  Col num of pole=   53.00  Col spacing (m)= 81270.0
Standard Latitudes=   25.00     25.00   Standard Longitude=   95.00

 ...

PAR    LEVEL       DAY        TIME    SRC FHOUR     FDAY       FTIME  GRID  PRO
---- --------- ------------ -------- ---- ----- ------------ -------- ----- ----
T     850 MB   05 JUL 01186 00:00:00  ETA     0 05 JUL 01186 00:00:00    99 LAMB
Total pts=  6045 Num rows=  65  Num columns=  93    received:  2001186 020509Z
Temperature
GRIB ID numbers: Geographic =211; PAR = 11; Model ID = 84; Level type =100
Units of gridded variable are K    Scale of variable is:   2
Lambert Conformal Tangent Cone Projection
Row num of pole= -113.34  Col num of pole=   53.00  Col spacing (m)= 81270.0
Standard Latitudes=   25.00     25.00   Standard Longitude=   95.00
PAR    LEVEL       DAY        TIME    SRC FHOUR     FDAY       FTIME  GRID  PRO
---- --------- ------------ -------- ---- ----- ------------ -------- ----- ----
Z     900 MB   05 JUL 01186 00:00:00  ETA     0 05 JUL 01186 00:00:00   100 LAMB
Total pts=  6045 Num rows=  65  Num columns=  93    received:  2001186 020509Z
Geopotential height
GRIB ID numbers: Geographic =211; PAR =  7; Model ID = 84; Level type =100
Units of gridded variable are GPM  Scale of variable is:   2
Lambert Conformal Tangent Cone Projection
Row num of pole= -113.34  Col num of pole=   53.00  Col spacing (m)= 81270.0
Standard Latitudes=   25.00     25.00   Standard Longitude=   95.00
Number of grids listed = 100
GRDLIST - done

Since the long listing (FORM=ALL) from GRDLIST tells us what the grid
is, it would be possible to capture the geographic ID for each grid into
a file (DEV=T fname) and then parse the file to see which grid numbers
in the GRID file are the ones desired.  You could then do the GRDCOPY
explicitly specifying the grid number as in:

GRDCOPY RTGRIDS/ETA MYDATA/GRIDS.1234 GPRO=LAMB GRID=bgrid egrid

This is, of course, McIDAS ugliness, but it works.

Too bad you missed the 4th.  The BBQ at Tammy & Mike's was fun, AND we
could see the fireworks from Folsom from their back yard.

Tom

>From address@hidden Thu Jul  5 19:42:43 2001
>Subject: Re: 20010705: GRD commands

Hi Tom-

Thanks for the GRD feedback.  I was hoping that I could use the GEO=
keyword or something.  I'll just cut back on the grids I ask for.  

Don