The exp2dp function returns the exponential function of a real floating-point argument a. The return value is the number 2 raised to the power a. If the magnitude of a is too large, the maximum double-precision floating-point number (1.797693e+308 = 2^1024) is returned.
Parameters:
[in]
a
= Input double
Returns:
Resultant double
Special Cases:
If | a | < 1.11e-16, then the return value is 1.0 for small arguments.
If a < -1022, then the return value is 0.0.
If a > +1024, then the return value is 1.797693e+308 = 2^1024 (maximum double-precision floating-point number).