doold, donew, docont
Clear one or more of the established, tentative and continuum models.
EXAMPLES
--------

0>clrmod
clrmod: Cleared the tentative model.
0>

0>clrmod true
clrmod: Cleared the established and tentative models.
0>

0>clrmod true,true,true
clrmod: Cleared the established, tentative and continuum models.
0>

PARAMETER
---------
doold   -  Default=false
           If specified as true, then the established model will be cleared.

donew   -  Default=true
           If this argument is omitted, or explicitly specified as
           true, then the tentative model will be cleared.

docont  -  Default=false
           If specified as true, then the continuum model will be cleared.

CONTEXT
-------
In difmap the term 'model' refers to a mixed list of delta, gaussian
and other simple components, which when superposed in the image plane,
form a facsimile of the source being mapped. This model is split into
three parts, an established model, a tentative model and a continuum
model. The function of the 'clrmod' command is to clear one or more of
these models.

When the 'clrmod' command is invoked with no arguments, it clears just
the tentative model. This is most useful to discard the latest results
of the 'clean' command, after cleaning too deeply.

When the 'clrmod' command is invoked as 'clrmod true', it deletes both
the established and tentative model, but leaves any existing continuum
model untouched. This is commonly invoked after the 'select' command
has been used to select a new data stream, when which the model for the
previous selection is a bad match to the new selection.

For more information about models type 'help models'.