g = _g_instantiate (g,"VAR", Value, ...) - Substitute all values in g.cmds. For each occurence of "" in g.cmds{:}, a value is seeked either on the command line (preferentially) or in g.values.(VAR). If no value is found, an error occurs. Otherwise, the value is used to substitute "". Non-string values are converted to strings by sprintf ("%g",value). See also: g_new, g_set.