GRDINFO
Lists,
modifies, or statistically analyzes grid point values.
Formats
GRDINFO sdataset EDIT ddataset [keywords]
GRDINFO sdataset HIST [keywords]
GRDINFO sdataset LIST [keywords]
GRDINFO sdataset STAT [keywords]
Parameters
sdataset |
source
ADDE dataset name and absolute position; specify one of the following
formats: |
|
|
group/descriptor.position
alias.position |
|
use
only positive integers or ALL (all positions) for position (no
default for group/descriptor or alias; default=ALL
for position) |
EDIT |
modifies
grid point values and copies the new grid to ddataset |
HIST |
displays
histogram for grid point values |
LIST |
lists
grid point values |
STAT |
displays
statistical analysis for grid point values; statistics include the minimum
and maximum values, mean, and standard deviation (default) |
ddataset |
destination
ADDE dataset name and absolute position; specify one of the following
formats: |
|
|
group/descriptor.position
alias.position |
|
use
only positive integers for position |
Search Keywords
DAY= |
d1
. . dn |
selects
grids with the specified days |
DRAnge= |
bday eday inc |
selects
grids in the range of days bday through eday, incremented
by inc days (no default for bday; eday default=bday; inc default=1) |
FDAy= |
selects
grids with the specified forecast day; a grid's forecast day is determined
by adding the forecast hour to the day and time; for example, a 12 UTC
grid from day 2000100 with a forecast hour of 72 has a forecast day of
2000103; you cannot use FDAY with the FHOUR or FRANGE keyword |
FHOur= |
h1
. . hn |
selects
grids with the specified forecast hours; you cannot use FHOUR with the
FRANGE, FDAY or FTIME keyword |
FRANGe= |
bhr ehr inc |
selects
grids in the range of forecast hours bhr through ehr, incremented
by inc hours; you cannot use FRANGE with the FHOUR, FDAY or
FTIME keyword (no default for bhr; ehr default=bhr; inc default=1) |
FTIme= |
selects
grids with the specified forecast time; a grid's forecast time is determined
by adding the forecast hour to the time; for example, a 12 UTC grid with
a forecast hour of 18 has a forecast time of 6 on the following day;
you cannot use FTIME with the FHOUR or FRANGE keyword |
GPRo= |
g1
. . gn |
selects
grids with the specified projection, for example, MERC, PS, LAMB, EQUI |
GRIB= |
geo par model level
selects
grids with the specified GRIB codes; the four values are the geographic,
parameter, model and level codes that can be listed with GRDLIST FORM=ALL;
values specified as an X (a placeholder) or not specified at all will
match any GRIB code |
GRId= |
bgrid egrid |
selects
grids bgrid through egrid in the grid file specified
in the dataset parameter; enter a grid number or LAST (last
grid) for bgrid and egrid; see the Remarks (no default
for bgrid; egrid default=bgrid) |
LEV= |
l1[u1]
. . ln[un] |
selects
grids with the specified levels and units, e.g., SFC, 850[MB], 5000[M];
units are optional but must be in square brackets if specified |
PARam= |
p1
. . pn |
selects
grids with the specified parameters, for example, T, Z, RH; do not use
with the DERIVE keyword; see the Remarks |
SRC= |
s1
. . sn |
selects
grids with the specified sources, for example, MDX, GFS, ETA |
TIMe= |
t1
. . tn |
selects
grids with the specified times |
TRAnge= |
btim etim inc |
selects
grids in the range of times btim through etim, incremented
by inc (no default for btim; etim default=btim; inc default=1,
meaning one hour) |
Derived Grid Keywords
DERive= |
selects
the component grids needed to derive a grid with the specified parameter,
for example, DST or VOR; the grid listed with the HIST, LIST, or STAT
parameters does not exist, but the components needed to derive such a
grid do; do not use with the PARAM keyword; see the Remarks |
MERidional= |
YES |
adds
a correction term to account for the convergence of longitude lines at
the poles |
|
NO |
does
not add a correction term; only valid with DERIVE=ABV, DSH, DST, DVG,
or VOR; see the Remarks (default) |
PLAnet= |
planet
for which derive calculations are done; valid options are MERCURY, VENUS,
EARTH, MARS, JUPITER, SATURN, NEPTUNE, URANUS (default=EARTH) |
Mathematical Operations Keywords
Gn= |
'clause1; clause2; .
.; clausen'
grids
to be used with the MATH keyword; separate select clauses with semicolons;
single quotes are mandatory; specify clause using the following
format:
valid
options for searchkeyword are DAY, FHOUR, GPRO, GRID, LEV, PARAM,
SRC, TIME; you can specify numbers between 1 and 99 in the keyword name
(G1, G2, . . , G99); see the Remarks |
INFo= |
'text' |
string
placed in the header of the copied grid when the MATH keyword is used;
maximum of 48 characters |
MATh= |
'expression' |
mathematical
operation to perform on the grids specified with the Gn keywords;
single quotes are mandatory; see the Remarks |
NEWpar= |
param punit level lunit src
header information for the grid copied with the MATH keyword; parameter
and level values, and associated units |
|
|
param |
grid
parameter; four characters maximum (default=MATH) |
|
|
punit |
units
of grid parameter; four characters maximum (default=NONE) |
|
|
level |
grid
level (default=from grid) |
|
|
lunit |
units
of grid level; two characters maximum (default=from grid) |
|
|
src |
grid
source; four characters maximum (default=from grid) |
Grid Point Selection Keywords
COL= |
bcol ecol |
range
of columns to list or edit; specify MAX for the last column in the grid
(default=1 MAX for the STAT and HIST options; default=1 bcol for
the LIST and EDIT options) |
LAT= |
lat1 lat2 |
range
of latitudes to list or edit; range must be south to north (default=grid
latitude extents) |
LON= |
lon1 lon2 |
range
of longitudes to list or edit; range must be east to west (default=grid
longitude extents) |
RANge= |
bval eval |
range
of grid point values to list or edit; bval can be MISS for missing
values (default=all values) |
|
MISS |
list
or edit grid points with missing values |
ROW= |
brow erow |
range
of rows to list or edit; specify MAX for the last row in the grid (default=1
MAX for the STAT and HIST options; default=1 brow for the LIST
and EDIT options) |
EDIT Option Keywords
DEL= |
YES |
delete
the destination grid file before copying the edited grid; see the Remarks |
|
NO |
do
not delete the destination grid file (default) |
DGRid= |
beginning
grid number in the destination grid file to place the edited grids; this
keyword may overwrite existing grids; see the Remarks (default=append
after the last grid in the grid file) |
MAXgrd= |
maximum
number of grids the newly created destination grid file can store; see
the Remarks (default=1000) |
TITLE= |
'text' |
title
of the newly created destination grid file; 32 characters maximum; see
the Remarks |
VALue= |
num |
value
to assign to grid points specified with the grid point selection keywords |
|
MISS |
assigns
a missing data value to the specified grid points |
Output Keywords
BINsize= |
increment,
or bin width, for the histogram; valid only with the HIST option (default=from sdataset) |
BYTecount= |
YES |
lists
the number of bytes received from the server |
|
NO |
does
not list the number of bytes (default) |
FORmat= |
output
format for grid point values; if multiple parameters are requested, FORMAT
cannot be specified; see the Remarks |
NUM= |
number
of grids matching the criteria defined with the search keywords to list
or edit; for example, if you specify NUM=50, the first 50 grids matching
the search keywords are used (default=1) |
|
ALL |
use
all grids matching the search keywords |
SUBsect= |
slat nlat elon wlon incrow inccol
geographic
region to subsect from the source grid, and row and column reduction
intervals to use within the subsect region, where: |
|
slat,
nlat |
southern
and northern latitudes of the subsect region |
|
elon,
wlon |
eastern
and western longitudes of the subsect region (slat, nlat, elon, wlon defaults=source
grid bounds) |
|
incrow, inccol |
row
and column reduction intervals; 1 means use every row/column of grid
points in the subsect region, 2 means use every other row/column, etc.;
when subsecting a conformal projection grid, the incrow and inccol values
must be the same (default=1 for both) |
|
Note:
If the source grid is a McIDAS grid, you can subsect it by row and column
instead of latitude and longitude. To do so, specify row and column numbers
instead of latitudes and longitudes in the first four parameters, and
specify ROWCOL as the seventh parameter. For example, SUBSECT=10 40 80
160 1 2 ROWCOL uses rows 10, 11, 12, ..., 40 and columns 80, 82, 84,
..., 160 for the subsect region. (If you don't include the ROWCOL at
the end, it will treat 10 and 40 as latitudes, and 80 and 160 as longitudes.) |
UNIt= |
units
to list for grid point values; not valid if multiple parameters are requested
with the PARAM keyword (default=from grid header) |
Remarks
Individual
grids are stored in grid files. Each dataset position points to a single grid
file. GRDINFO lists or edits individual grid point values in one or more grid
files in a dataset. Use the search keywords to limit grid selection.
Use the RANGE,
LAT and LON, and ROW and COL keywords to limit the selection of grid points.
Using a combination of these grid point selection keywords limits grid points
to those that meet all the specified criteria.
More than
one grid can be altered using the EDIT option; however, only one value can
be assigned to modify all the grids.
If you specify
DEL=YES or a position number of a nonexistent grid file in the ddataset parameter,
the edited grids are copied into a newly created grid file with the attributes
specified in keywords MAXGRD and TITLE.
Using the
DGRID keyword may result in grids being overwritten in the destination grid
file. For example, if the destination grid file has 50 grids (in grids 1 to
50) and you specify NUM=10 DGRID=25, the edited grids will overwrite grids
25 to 34 in the destination grid file.
The GRID
keyword copies grids from the grid file specified with the sdataset position number;
the default position value, ALL, is not valid. When using the GRID
keyword, do not specify additional search keywords, PARAM, LEV, DAY, etc.,
or NUM.
When using
the DERIVE keyword with the LIST, HIST, and STAT options, GRDINFO lists information
for a virtual grid: a grid that could be derived. The command searches for
grids with components needed to derive a grid with the specified parameter.
Only one derived parameter can be specified at a time, but you can request
multiple grids, by specifying multiple levels or times, for example. Use GRDCOPY
with the DERIVE keyword to create derived grids.
Use the FORMAT
keyword options below to format output based on FORTRAN designators for data
output:
| Designator |
Description |
| I |
integer |
| F |
floating
point |
| E |
exponential |
To specify
a parameter's output format, use a designator followed by a number. For example,
I4 specifies an integer of up to four digits; F10.1 specifies a floating point
decimal of up to 10 digits (including the decimal point) with one digit to
the right of the decimal; E10.3 specifies an exponential number of up to 10
characters (including the decimal point and the four-character exponential
flag) with three digits to the right of the decimal. Specify an X to use the
parameter's default format. If the specified integer or floating point format
is too small for the parameter's values, a series of asterisks (***) is displayed.
See Also
See the Remarks
and Examples in the GRDCOPY or GRDDISP command
for additional information on DERIVE, MERIDIONAL, and MATH keywords.
Examples
GRDINFO NGM/12
This entry
lists the statistics for the first grid in the first grid file in dataset NGM/12.
The statistics include the minimum and maximum values, mean, and standard deviation.
GRDINFO RT/GRID.10 HIST PARAM=T LEV=850 FHOUR=12
This entry
displays the histogram of the 12-hour forecast, 850 mb temperature grid in
position 10 of dataset RT/GRID.
GRDINFO GRIDS/ETA.1 DERIVE=SPD LEV=500 FHOUR=48
This entry
lists the statistics for a wind speed grid that could be derived from 500 mb,
48-hour forecast time component grids in position 1 of dataset GRIDS/ETA.
GRDINFO CASEA.21 LIST PARAM=T LEV=700 FHOUR=24 ROW=15 COL=30 40 UNIT=C
FORMAT=F5.1
This entry
lists the temperature values stored in columns 30 through 40 of row 15 of a
24-hour forecast, 700 mb temperature grid in position 21 of the dataset with
the alias name CASEA. The temperatures are listed in degrees Celsius. The temperature
output is formatted as real numbers containing up to five digits (including
the decimal point) with one digit to the right of the decimal point.
GRDINFO BLIZZARD/NGM.8000 EDIT BLIZZARD/EDIT.4003 VALUE=MISS LAT=40
45 LON=90 95 DERIVE=VOR LEV=500 FHOUR=48 DGRID=15
This entry
creates a derived grid of relative vorticity using the 48-hour forecast, 500
mb u- and v- wind component grids in position 8000 of the dataset BLIZZARD/NGM.
The new grid is placed in grid number 15 in position 4003 of the dataset BLIZZARD/EDIT,
overwriting all pre-existing data. The values of grid points between 40° and
45° latitude and between 90° and 95° longitude are changed to missing
data values (MISS).