.changePrecision: Change precision.
Description
This function converts double values to double values in a given
precision (only correctly working for cut a higher precision to a lower one;
e.g.  IEEE 754 double precision to IEEE 754 single precision)
Usage
.changePrecision(x, size)
Arguments
- x
- double, a vector of double values which should converted.
 
- size
- integer, how many bytes using for target precision
e.g. IEEE 754 single precision:- size=4,
IEEE 754 double precision:- size=8