Originally Posted by

**notPrime** Thanks a lot. I have another question (Sorry, I literally started using Matlab last week). I have two m files fitness and DoIt. In DoIt, I have:

...Some code

fitness(gene2,gene3,gene4,gene5,gene6,actualYValue s,measureOfFit1)

In fitness, I have:

%This function measures the fitness of our chromosome by comparing the predict values to the

%actual values. The measure of fit is the square of the pearson correlation coefficient.

function[measure] = fitness(x1, x2, x3, x4, x5,yValues,**fitnessValue**)

%Here we form the matrix and carry out the linear regression calculations

firstColumn=ones(29,1);

theMatrix = [firstColumn, x1, x2, x3, x4, x5];

c=inv(transpose(theMatrix)*theMatrix)*transpose(th eMatrix);

%Now we will multiply the transpose of the c matrix by the the transpose of theMatrix to

%calculate our predicted y values. Using linear regression.

finalMatrix = transpose(transpose(c)*transpose(theMatrix));

predictedYValues = finalMatrix*yValues;

measure = linreg(predictedYValues, yValues);

**fitnessValue**=measure;

I'm trying to get the fitness function to reflect the changes in the fitnessValue done in the fitness function back to the DoIt function. How would I do this? Is there anything like the ampersand in C?