free grads

This script, is really more of a function, the best way to use this would be to copy the contents of this script into the bottom of the script you wish to use it in.  This function reads in temperature and moisture information and returns a good approximation of both potential and equivalent potential temperature.

This function asks for up to four inputs, though only temperature and moisture inputs are required.
It is capable of calculating  equivalent potential temperature given four different moisture input variables:

1. Relative Humidity (-rh)
2. Mixing Ratio (-r)
3. Vapor Pressure (-e)
4. Specific Humidity (-q)

The default is relative humidity.

set lat|lon|lev|time|ens

set lat|lon|lev|time|ens val1 <val2>

This set command sets one dimension of the dimension environment using world coordinates.

set x|y|z|t|e

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.