[Flopi]

Dear all,
I have an issue with my code, and I can't seem to find a way around. I am trying to calculated explicitly a volScalarField as the logarithm of another field:

volScalarField a
(
IOobject
(
"a",
runTime.timeName(),
mesh,
IOobject::MUST_READ,
IOobject::AUTO_WRITE
),
mesh
);

volScalarField b
(
IOobject
(
"b",
runTime.timeName(),
mesh,
IOobject::MUST_READ,
IOobject::AUTO_WRITE
),
mesh
);

a = log(b);

The code compiles properly, but when I try to use the value of a, in another explicit equation:


c = a;

then the program fails and 'generates stack trace...'.
I guess it's because there is a problem of variable type, but when I try a ForAll loop to give each cell the value, I got a problem with incompatible type during compilation.

So basically my question is: how to easily take the logarithm of a volScalarField such that the result is a volScalarField whose values are the log of the previous field ?

Thank you for your help !

[Santiago]

... or maybe its because b is not positive?

[Flopi]

There are indeed some zero values in b (nothing negative though).



As I tried to make the calculation with a ForAll loop and failed because of some type mismatch, I decided to remove the -inf values after the a = log(b) calculation by looping on a and removing the -inf values using an auxilliary Field (calculated somewhere else on my model) which knows where the zero values of b were (not sure if that's clear).


It seemed to work as when I print the new cleaned a, I don't have any -inf values in the list (nor the boundary conditions). But I guess something must have remained and makes the calculation fail ?