Widget:

• When a data FILE is opened, buttons appear at the bottom of the main widget and are labeled with the field names. This allows for any field to be selected by clicking with the left mouse button.

  Additional field buttons may be added to the IVE Main Window using the FIELD command. When a field is defined at the command line, that field is calculated and a button appears. The new field can subsequently be selected by merely clicking on the button.

• FIELD = field_name
• FIELD = expression, name

• field_name: valid choices for field_name are either the name of a field variable or a diagnostic variable that the user has made provision to calculate either at the command line or in CALC_FIELD which is a subroutine of the transform file.
• expression: a mathematical expression in terms of the existing field variables or diagnostic variables (see Diagnostic Computations Using the Command Line).
• name: the name of the new field variable defined by the expression

• FIELD=T
• FIELD=A*B/C, X
  produces a new field called "X" which represents the result of the expression A*B/C
• FIELD=VORT
  where "VORT" is a diagnostic variable which represents the vorticity field

• In the case of staggered grids such as U and P, one may use the expression (U@P), where the value of U is linearly interpolated to the P grid (See also Diagnostic Computations Using the Command Line). EXAMPLE: FIELD=(U@P)*(W@P), UW
• When a field from the data file is read in, it is read into memory and stays in memory until either a new data file is opened, or memory is freed using the FREE command.