Computing values from a subsection of a data file

Greetings all,

    As I brush the rust off of MATLAB gradually ;) I'm trying to compute values from a particular data file for a simulation I am doing. The problem is, the results aren't quite right, except for the first value.

   So my code is:

    z1 = data(1:10,2);
    Rz1 = 1/(sqrt(4*z1.^2 + 1))

   Now, data(1:10,2) is from my data file where elements 1 through 10 in column 2 are all zero, and according to the equation I stated at Rz1, all the results should be one (so in essence a row of 10 ones). But I get 1 0 0 0 0 0 0 0 0 0 0 as my output, which is not correct.

    Can someone point out my mistake? I figure I'll ask this now since my computation gets more complex from here on out, so I want to get it right.

   Thanks!
    Jesse

Answer 1

[Fangjun Jiang]

Very close. Just missed one dot.

%z1 = data(1:10,2);
z1=zeros(10,1);
Rz1 = 1./(sqrt(4*z1.^2 + 1))

[Jesse]

Ahh time to pop the champagne! Thanks Fangjun!