GrADS command quick list

GrADS command list :


A detail of GrADS commands can be found here :



$  grads     # start GraDS

ga->  ! ls  -ltr        # use ! to send command to shell.

ga->  open model.ctl    # open param description file

ga->  query file    # see what is in this file

ga->  d ps     # display

ga->  clear           clears the display
ga->  c

ga->  set lon -90     sets longitude to 90 degrees West
ga->  set lat 40      sets latitude to 40 degrees North
ga->  set lev 500     sets level to 500 mb
ga->  set t 1         sets time to first time step

ga->  set lon -180 0     X is now a varying dimension
ga->  set lat 0 90

Note: from now on, "ga->  " is omitted. 

c
set t 1 5

display (tsfc-273.16)*9/5+32

d sqrt(u*u+v*v)   # conversion

d mag(u,v)        # built-in function mag: magnitude of the wind

d ave(hgt,t=1,t=5)     # built-in function ave :

d hgt-ave(hgt,x=1,x=72)   # take means over longitude to remove the zonal mean:

d hgt(t=2) - hgt(t=1)     # perform time differencing


The complete specification of a variable name is:       name.file(dim +|-|= value, ...)

ga-> q   files                # check how many files are open.
File 1 : gfs.t12z.pgrb2.0p25.anl
  Descriptor: gfs.t12z.pgrb2.0p25.anl.ctl
  Binary: gfs.t12z.pgrb2.0p25.anl
File 2 : gfs.t12z.pgrb2.0p25.f000
  Descriptor: gfs.t12z.pgrb2.0p25.f000.ctl
  Binary: gfs.t12z.pgrb2.0p25.f000
ga-> set   dfile  1           # set default file to file 1.
Default file set to: gfs.t12z.pgrb2.0p25.anl
ga-> q    file           # check to see what is in file 1.

display hgt.2 - hgt.1

d hcurl(u,v)      # horizontal relative vorticity via finite differencing

d vint(ps,q,275)  # a mass weighted vertical integral

set cint 30     # contour interval
set ccolor 3    # contour color 
set csmooth on     # apply a cubic smoother

# gxout : graphics output
set gxout shaded     # alternate ways of displaying the data  .
set gxout contour
draw title 500mb Heights and Vorticity    # annotate title

set gxout vector    # view wind vector
d u;v