Matlab

Timing of the inversion of a sparse matrix
Dear all, I need the inverse of a sparse 5544X5544 matrix, where I tried some different options in MATLAB but the results are so different which raised my attention, especially the one on inv. I used cholesky, lu decompositions and direct inv in MATLAB, here is the code to test the inversion timing clc, ... 23 Apr 2010 17:33

mxArray serialization
I'm using Matlab API in C++. I open a mat file (using matOpen function), and I read the first (and only variable) in it to an mxArray pointer (mxArray*). I'd like to copy the memory representation of this mxArray in order to reuse it later on, without the overhead of opening the matfile again. ======================... 3 May 2010 05:30

combine two matrices
Hi there, I want to combine two variables. The variables are: data <53x2 double> textdata <71x10 cell> The first cell (1,1) of data had to be placed in row 7 and column 11 of textdata. Anyone an idea? Muchos gracias! ... 23 Apr 2010 17:33

Problem whit function polybool
Hi everybody, I am new in this forum and i have a problem whit the function polybool. I must use this function in an algoritm for the tracking of a target in a cellular network, but i have a problem. When i use this function, also white example code in the help: theta = linspace(0, 2*pi, 100); x1 = cos(th... 23 Apr 2010 17:33

making a linear filter mask and apply to an image
any help please ... 23 Apr 2010 17:33

Quantifying noise
Greetings, After making an image noisy but taking the fft and sweeping a gaussian distribution through it . What is the best to to find out the percent noise in the image. Ie: if sigma=X( width of the gaussian).... %noisy=Y Thanks in advance for your help. ... 23 Apr 2010 17:33

find roots of a spline
"John D'Errico" <woodchips(a)rochester.rr.com> wrote in message <hqpirp$11p$1(a)fred.mathworks.com>... Rather than using roots, use the explicit formula for the roots of a cubic polynomial, given the coefficients. This can be done in a fully vectorized form, so all the intervals can be processed at once. ... 23 Apr 2010 17:34

Interpretation within FOR loop
"Ali Y." a hint: - look at your data... i2=2; b(i2-1):b(i2+1) % ans = Empty matrix: 1-by-0 us Hi us, thanks for your reply, but it doesn't work, i have already tried it before like YI=interp((a(i2-1):0.1:a(i2+1)),(b(i2-1):-0.1:b(i2+1)),XI); well, Y... 23 Apr 2010 17:33

CanOpen and xPC target
Hi all, I am trying to create a xPC Target model that comunicates via CanOpen with 4 drives. I should be able to receive information that is stored in the drive and also transmit torque reference values. I already read everything about SDOs and PDOs in several manuals, but unfortunately I didn't found anything abou... 23 Apr 2010 17:33

Map or Region
Hello I am pretty new to this field. I would like to emulate a map/region for calculating radio transmitters coverage area. I am not sure how it is the best way to implement this area. Could I try to define as an X,Y array or using some map related object that matlab offers? Best Regards Alex. ... 23 Apr 2010 17:33