Forum Discussion
What is the code for increasing calculation tolerance?
I am now implementing my program in Xpress Mosel IVE. I have a problem about calculation tolerance in Xpress. I calculate factorial of 20 (20!) by using "prod" function. But i found out that Xpress r...
The MAX_INT value of Mosel is 2 to the power of 31 (that is, roughly 2E9). If you need any larger values you should use real numbers, so for example for your case:
setparam("realfmt", "%.20g") ! Change display format to show up to 20 digits
forall(n in 10..20) writeln(n, "! = ", prod(i in 1..n) real(i))
Note that the correctness of the results will depend on what can be achieved / correctly represented in floating point arithmetic on your computer system (Mosel reals are double-precision floating point numbers).
Mosel tolerance settings do not have any impact on calculations (the parameter 'zerotol' is applied in comparisons between reals).