`set x|y|z|t|e `

*val1 <val2>*

This sets one dimension of the dimension environment using grid
coordinates. You may use whatever coordinates are convenient to you.
Issuing `set lon`

is equivalent to issuing `set x`

,
both set the `x`

dimension. The difference is only the units
you wish to use when entering the command.

When you enter just one value, that dimension is said to be "fixed". When you enter two values, that dimension is said to be "varying". The combination of fixed and varying dimensions defines the dimension environment.

The 'set e' command is only available in GrADS version 2.0+, when the ensemble dimension was introduced.

An important note: When you enter dimensions in grid coordinates, they are always converted to world coordinates. This conversion requires some knowledge of what scaling is in use for grid to world conversions. The scaling that is used in all cases (except one) is the scaling of the DEFAULT FILE. The exception is when you supply a dimension expression within a variable specification.

If you are setting the T or E dimension using grid coordinates, the value given in

or
*val1*

may be the word "last" to set the dimension to the max value of that grid coordinate.
*val2*

`set t 1`

This sets time to the first time in the data set -- using
grid coordinates. T is now a fixed
dimension.

`set z 1 4`

This sets the vertical dimension to vary between the first and the fourth levels in the data set -- using
grid coordinates. Z is now a varying
dimension.

`set t 1 last`

This sets time to vary between the first and the last time in the data set -- using
grid coordinates. T is now a varying
dimension.

`set e last `

This sets the ensemble to the final member in the data set. E is now a fixed
dimension.