Fortran FUNCTION attribute conflicts with SUBROUTINE attribute

[Vrbic]

Hello, I'm trying to use Runge Kutta with adaptive stepsize from numerical recipes(page 742, https://websites.pmc.ucsc.edu/~fnimmo/eart290c_17/NumericalRecipesinF77.pdf ). I rewrote code but I have got failure messages both in an attachment. If I cut this subroutine everything is fine also this failure are independent on a definition of function 'derivs' which is causing the problem in calling.
Thank you for any advice.

 

[DrClaude]

Your first image is too small to read. Looking at the second one, in rkck the declaration

double precision, external :: derivs

would be valid for a function, not a subroutine. it should be simply

external :: derivs

 

[Vrbic]

Your first image is too small to read. Looking at the second one, in rkck the declaration

double precision, external :: derivs

would be valid for a function, not a subroutine. it should be simply

external :: derivs

Good to know,
Thank you! SOLVED