The read-only variable GPVAL_ERRNO is set to a non-zero value if any gnuplot command terminates early due to an error. The most recent error message is stored in the string variable GPVAL_ERRMSG. Both GPVAL_ERRNO and GPVAL_ERRMSG can be cleared using the command reset errors.
Interactive terminals with mouse functionality maintain read-only variables
with the prefix "MOUSE_". See mouse variables (p. ) for details.
The fit mechanism uses several variables with names that begin "FIT_". It
is safest to avoid using such names. "FIT_LIMIT", however, is one that you
may wish to redefine. Under set fit errorvariables, the error for each
fitted parameter will be stored in a variable named like the parameter, but
with "_err" appended. See the documentation on fit (p. ) for details.
See user-defined variables (p. ), reset errors (p.
), mouse variables (p.
), and fit (p.
).