function A(meanValue) = HW3Part3Function
A(meanValue) = mean((A(1:2:end,:),2))
When you define your function, the function declaration line should include the names of the variables into which the input arguments will be stored and the names of the variables to be returned to the caller. It cannot contain expressions like A(meanvalue).
When you call your function, specify the exact values on which you want your function to operate. The call can contain expressions.
This is an incorrect way to define the addme function:
This is a correct way to define the addme function:
and these are correct ways to call the addme function.
theOutput(17) = addme(2, 3)
theOutput(2) = addme(pi^2, sind(45))
In addition, nowhere in your code prior to using the A and meanValue variables do you use them, so even if you corrected the function declaration line your function still would not work.
I second Cris LaPierre's suggestion that you go through the MATLAB Onramp as I believe it will teach you how to write functions in MATLAB.