How can I get rid of monotonically increasing error in MATLAB?

I am using a look up table in my model and calibration i need for this table is decreasing. I have to implement this calibration for my function to work but when I try to run the model I am getting the monotonically increasing error. How can I get rid of this?

[Walter Roberson]

Is that for Simulink? If not then which function is being used?

Answer 1

[Walter Roberson]

If V is monotonically decreasing, and x is to be looked up in it, then instead look up -1*x in -1*V