[Ipopt] IDX_STY and NEW_X in the Fortran sample (fwd)

Daniel Feenberg feenberg at nber.org
Wed Nov 14 12:56:35 EST 2018

I am using ipopt with gcc Fortran under Linux and have two questions.

1) What does IDX_STY do? The sample fortran program sets it to 1,
but I can't find any indication of what this means.

2) I am unsure of how to handle NEW_X. Can I just add:

    IF(NEW_X.EQ.1) return

at the start of EV_G,EV_JACG,EV_F and EV_GRAD_F, after the
declarations and before any computations? Is the constant
1 or 0? When I print NEW_X, it always seems to be zero.

Daniel Feenberg

More information about the Ipopt mailing list