matlab code to solve absolute error

I tried to solve the summation of absolute error by entering the following code in Matlab program. However, it display an error. So, is there anyone who can help me to edit or correct this one, sending other support link or code.

Function S=sum(a)
Xi=[Xi,....Xn]'
Yi=[Yi,...Yn]'
f(x)= ao+a1x
S=0
For i=1:n
  S=S+abs(f(Xi)-Yi)
  end
  S

Thanks in advance.

[John Gebre]

Hi there, I am looking your support on the above posted Matlab code.

Answer 1

[Image Analyst]

Tons of problems with this. Misspelling of function as "Function" (MATLAB is case sensitive). Improper assignment of Xi and Yi (recursive, and no value had been set for Xn. Equation for f(x) is wrong in multiple ways. Used built in function, sum(), for the name of your own custom function. In the for loop, the sum doesn't match what you've asked in your prior two questions on the same formula. Misspelled "for" as "For". No indexing of Xi and Yi in the loop (like, it's not Xi(i) and Yi(i)). And so on. Why don't you just look at my answer to your two prior postings of this question - this one just made it worse.