Organizing output in MATLAB


by Providence88
Tags: matlab, organizing, output
Providence88
Providence88 is offline
#1
Sep30-09, 04:44 PM
P: 7
So I have this code:

function ApproxSinDeriv(x,n)
h=.5;
for i = 0:n
    h;
    approx = (1/(2*h))*(sin(x+h)-sin(x-h));
    error = abs(approx-cos(x));
    h = h/2;
    A=[i,h,approx,error]
end
Basically, it's a three-point formula for approximating a derivative, where the variables n = the number of iterations, x = the input value for the sin function, i = iteration number, approx=the approximation of the derivative, and error = the difference between the actual derivative and the approximation.

I put A equal to a matrix of these values, but the output comes out in 30 clunky, individual, one-row matrices.

How would I go about putting this data in an array? That is, one nice clean matrix with 30 rows and 4 columns [i,h,approx,error]?

Thanks!

-Eric.
Phys.Org News Partner Science news on Phys.org
Cougars' diverse diet helped them survive the Pleistocene mass extinction
Cyber risks can cause disruption on scale of 2008 crisis, study says
Mantis shrimp stronger than airplanes
trambolin
trambolin is offline
#2
Oct1-09, 04:24 AM
P: 341
function [A] = ApproxSinDeriv(x,n)
A = zeros(n+1,4)
h=.5;
for i = 0:n
    approx = (1/(2*h))*(sin(x+h)-sin(x-h));
    error = abs(approx-cos(x));
    h = h/2;
    A(i+1,:)=[i,h,approx,error];
end
Providence88
Providence88 is offline
#3
Oct1-09, 12:18 PM
P: 7
Thank you! That worked great!


Register to reply

Related Discussions
(MATLAB) Ignoring output arguments Math & Science Software 6
Matrix Output (Matlab) Math & Science Software 1
Self-organizing quantum universe explained in July SciAm feature Beyond the Standard Model 47
Java project output problem. Can't output objects from a method. Engineering, Comp Sci, & Technology Homework 0
Self organizing systems : Conway's The Game of Life General Discussion 36