Obtains a scalar value from a parameter PAR_GET0x
There is a routine for each of the data types character, double precision, integer, logical, and real:
replace "x" in the routine name by C, D, I, K, L, or R respectively as appropriate. The VALUE
argument must have the corresponding data type.
Note that a scalar (zero-dimensional) parameter is different from a vector (one-dimensional) parameter containing a single value.