Math Forum / Math Software / MATLAB / July 2008

As I'm continuing to learn Matlab and testing different
matrix manipulations, I came up with an algorithm to do a
specific matrix "reshape" I needed.
Let's say the initial s matrix is:

Below is my experiment - I actually expected the opposite!

Elapsed time is 0.003197 seconds.

   I have a matrix with 25 columns ans 486 rows. I want
the mean of all columns. I want to sum all values of the
first row, second row....486 row. The final result I want a
matrix with 1 column and 486 rows, the matrix are the mean

Hello,
How do I store data after the users press the "Push Button"?
Basically what I'm doing is, the users will be asked to
click on the "Play" button for the audio, then they will be

I would like to create a matrix where one row is a shifted
version of the previous one, like this:
M=[0 1 0 1 0;0 0 1 0 1;0 0 0 1 0; 0 0 0 0 1;0 0 0 0 0]
The second row is the first row shifted to the right and

I have an original predictor matrix X0 with
size(X0) = [ m n0]
I'd like to perform the
linear-coefficient/quadratic-variable regression

I am using the push button to recieve data(each time you
push it pull in data) but there is an issue... if you click
it really fast more than once the data seems to "back up"
and might plot twice in one spot.  I plan on taking 36 data

I am buying either the ATI 4870 or Nvidia 280 GTX. For 3D
animations, movie creations, etc under Matlab and Virtual
Reality toolbox, which video card gives the best
performance? Some softwares recommend using Nvidia cards

Hi! I'm attempting to animate a line of variable height
scrolling across my gui Axes, built using GUIDE. Right
now, for starters, I'm just trying to get a single line of
constant height to scroll across the screen, using the

I'm not sure which is the most efficient way and 'fastest'
that would deal with these issues.
Say you have:
M= a matrix of 5x3 =[x, y, z];

I am trying to create a matrix [MxN] for principle component analysis.
My problem is that my waveforms do not all have the same vector length
N, there is a difference of 15 to 100 data points. I am unsure what
type of algorithm to use, or how in general to adjust the waveforms to

I have very large tridiagonal positive matrices (dim > 10000)
for which I need to find all eigenvalues. Matlab eig/eigs
routines are desperately slow and memory consuming. Did
anybody solve a similar problem?

suppose i have a binary image(i.e), a circle.
where the solid shape is 1, others as 0.
I have found its boundaries
Is there a function in Matlab to find the coordinates of

I have 3D array 109x91x91 and I want to multiply
submatrices (109x91) of it with other matrices, along the
third dimension. This I can do easily but I cannot figure
out how I can keep the 3D structure of the array at the end.

I followed a couple of webinars on deploying matlab
applications and I'm particularly interested in displaying a
matlab plot in a webpage in a .NET framework (unfortunately
the only feature missing in my matlab installation is the