ave(expr, dim1, dim2 <,tinc> <,-b>)
Averages the result of
expr over the specified
dimension range. If the averaging dimension is time, an
optional time increment
tincr may be specified.
q attr <fnum>
This command returns all the attribute metadata associated
with file number
fnum in a formatted manner. If no value
fnum is given, then the attributes for the default file
are returned. The output of 'q attr' may be read by the user in the command
window, or parsed by a script for the purpose of capturing the metadata and
including it in the analysis or display. There are three categories of attributes:
(1) global, which means the attribute is relevant for all the data in the file,
(2) coordinate, which means the attribute describes one of the four dimensions
(lon, lat, lev, or time), or (3) variable, which means the attribute is assoicated
with a particular variable in the file. The formatting of the attribute listing
is as follows:
Input ASCII data
grads does not directly handle data in ASCII format -- there is no such thing as 'dtype ascii'. ASCII data must be converted to into one of the binary data formats that are handled by grads. There are many ways to do this with a variety of programming/scripting languages and tools. Below is a very simple example of how you could do it using a grads script.
Suppose you have an ascii file that contains a column of 100 numbers:
set arrowhead size
size is the size of the arrowhead. The default
0.05. If set to
0, no arrowhead is plotted.
If set to a negative value, the size of the arrowhead will be scaled to
the size of the arrow. The value specified will be the size when the arrow
is one inch in length.
grads allows you use a single data descriptor file to aggregate multiple data files and handle them as if they were one individual file. The individual data files must be identical in the X, Y, and Z dimensions and have the same list of variables. The time range of each individual file must be indicated it its filename. Beginning with version 2.0, data files may also be aggregated in the ensemble dimension.
This function takes an areal average over an X-Y region. The syntax is:
aave(expr, xdim1, xdim2, ydim1, ydim2)
expr- any valid grads expression
xdim1- starting X dimension expression
xdim2- ending X dimension expression
ydim1- starting Y dimension expression
ydim2- ending Y dimension expression