filename, which should be the name of a
grads data descriptor file, also called a control file.
The standard file extension for grads data descriptor files is
.ctl. Provided you adhere to this standard, there is no need to type the extension
.ctlwhen issuing the
You will need to open at least one data-descriptor file before you can enter other grads commands.
- You can open more than one data-descriptor file. Each file is numbered according to the order in which it was opened.
Both of these commands will have the same effect -- opening the grads
data descriptor file