Martin Rohde wrote:
I have (simple) a question about using PPL 0.4:
I cannot find how to convert a coefficient (of a constraint or generator) to the normal integer type. In my code I do the following; c1 is a constraint which is defined earlier in the code. Now I try to convert a coefficient with
c1_int = mpz_get_si(c1.coefficient(Variable(0)))
but this doesn't work, probably because the coefficient is not of the regular gmp format (c1_int is a standard integer)
How can I convert coefficients to 'normal' integers (or double integers)?
Dear Martin,
if you want to go the safe way (something I would highly recommend), you should use a fragment like the following (perhaps incapsulating this functionality into a convenience function):
const Integer& c1_coeff_0 = c1.coefficient(Variable(0)); if (c1_coeff_0.fits_sint_p()) { long c1_int = c1_coeff_0.get_si(); // Use c1_int. } else { // c1_coeff_0 exceeds the range of signed integers. // Do something else. }
The chapter of GMP's manual "C++ Class Interface" will tell you more about the operations supported by mpz_class (which is the same as Parma_Polyhedra_Library::Integer).
By the way, thanks to your message we have discovered that the user's manual does not give any indication that Parma_Polyhedra_Library::Integer is the same as GMP's mpz_class. This will be fixed in future releases. Thanks!
Roberto