Allow indicated parameters to vary. (See also freeze.)
XSPEC> thaw [<parameter range>...]
where <parameter range> =:: <parameter no.> or
<param no.>-<param no.>.
The indicated parameter, or range of parameters, will be marked as variable
by the fitting commands, by setting their associated <delta> to
greater than zero (see newpar command). (Note that parameters with
<delta> values equal to zero are not affected. The newpar command must be
used to change these.) By default, the range will be the last range input by
either a freeze or thaw command. See the freeze examples for an example
of the use of the thaw command.