grads [ - ] b|l|p [ -c 'command ]
Where:
-l
run
grads in landscape mode.
The orientation question is not asked.
-p
run
grads in portrait mode.
The orientation question is not asked.
-b
run
grads in batch mode. No
graphics output window is opened.
-c 'command'
execute the
supplied
'command'
as the first
GrADS command after GrADS is started. For
example:
grads
-c 'query'
execute the query command after GrADS is started.
grads
is an interactive desktop tool that is
currently in
use worldwide for the analysis and display of earth science
data.
GrADS implements a 4-Dimensional data model, where the dimensions are usually latitude, longitude, level and time. Each data set is located within this 4-Dimensional space by the use of a data descriptor file. Both gridded and station data may be described. Gridded data may be non-linearly spaced; Gaussian grids and variable resolution ocean model grids are directly supported. The internal data representa- tion in a file may be either binary or GRIB.
Operations may be performed on the data directly, and interactively, by entering FORTRAN-like expressions at the command line. A rich set of built-in functions are provided.
In addition, users may add their own functions as external routines written in any programming language. The expression syntax allows complex operations that range over very large amounts of data to be performed with simple expressions.
GrADS is freely distributed over the Internet.
GADDIR
points to the directory containing
the GrADS
package.
GASCRP
held
a list of directories
containing GrADS
utility scripts and user scripts.
GAUDFT
points to the user defined function
table. If
this variable is not set, the function table
will not be read.
PATH
the environment variable PATH must
be
expanded by GADDIR.
example% setenv GADDIR /ford1/local/lib/grads
example% setenv GASCRP $HOME/grads/scripts
example% setenv GAUDFT $HOME/grads/udf/table
example% setenv PATH $PATH":$GADDIR"
Bourne shell
example% GADDIR=/ford1/local/lib/grads; export
GADDIR
example% GASCRP=$HOME/grads/scripts; export GASCRP
example% GAUDFT=$HOME/grads/udf/table; export GAUDFT
example% PATH=$PATH:$GADDIR; export PATH
example% grads -pc 'open data.ctl'
start grads and open data descriptor file
data.ctl
.
example% grads -bpc 'run script.gs'
running grads in batch mode, executing the
GrADS script script.gs
in portrait
mode.