Help in Translating mathematical equation into "matlab function" block in simulink

Dear all,

I am new to matlab simulink and encoutnered a problem while trying to model a fuel cell stack. I have an equation to be input into the "matlab function" block and would like some advice/assistance from the experts here.

equation: V = E° + (3RT/4F) ln (P2/P1) – (i + in)*r – A ln((i + in)/ io) + B ln (1 – (i + in)/ il)

The variables are R, T, i and P2. THese values together with P1 (value 1) are mux as input to the "matlab function" block. The constants are: E°=1V, F=96487, in=2mAcm-2, r=0.03 ohm.cm2, io=0.067 mAcm-2, A=0.06V, B=0.05V and il=900 mAcm-2.

The output of this "matlab function" block is single output to a sink.

Any advice/help rendered will be greatly appreciated. Thank you.

[K E]

What error are you getting?