I'm attempting to use IVOAM, a variable Adams Method, for a three dimensional 2nd order differential equation. I'm running IMSL Fortran Library ver. 7.0.0. on a MacBook Pro running Mac OS X ver. 10.9.1 using Absoft's Pro Fortran 2014.

The call statement I'm using in my program was fashioned after the example shown in the IMSL Math Library pdf file, pages 1112 to 1117:

call IVOAM( ido, forces, t, tstop, xstate, hidrvs, neqs, korder, eqnerr, hinc, hdec, hmin, hmax )

The error message I get from IVOAM is

*** TERMINAL ERROR 17 from d_ivoam. The step length, H =

*** 2.225073858507203-308, is so small that when Tn + H is formed,

*** the result will be the same as Tn, where Tn is the base value

*** of the independent variable. If this problem is not due to a

*** nonintegrable singularity, it can probably be corrected by

*** translating t so that it is closer to 0. Reducing the error

*** tolerance for the equations through argument EQNERR may also

*** help with this problem.[/INDENT]

The parameter ido is set to one (1) before the first call to IVOAM. I get this error message regardless of the values for eqnerr. The magnitude of the step length leads me to believe that I must be missing an argument for the step length. However, the documentation for IVOAM shows no such parameter.

Please advise.

Orbital Mechanic.