Matlab

Parallel matrix multiplication w/ fminunc - not working?
Hi, Maybe a MATLAb tech can help out. I noticed the following problem when using the function fminunc. After each iteration, the fminunc function updates the approximate Hessian matrix by doing a series of matrix multiplications, the most computationally demanding of which would be a multiplication of the form H2 =... 12 Feb 2010 16:50

Matlab Image Acquisition Problem
Hi all, I am trying to acquire images from a usb frame grabber (Sensoray 2255). The device driver is compatible with Directx 9.0c and I was able to use AMCAP as well as VLC player to capture from all 4 channels of the frame grabber. However, no detectable devices show up when I try to query it from Matlab using imaq... 19 Feb 2010 07:37

Abort problem on Mac (Matlab 2009b, 64 bit edition)
Several users have asked how one can abort a Matlab execution on the Mac, short of killing the Matlab application. I could not make it work using the Gui, but Ctrl-c works if you run Matlab in the terminal. That's ok for me, maybe it'll help others too with the same problem. To start a terminal session, just open your ... 12 Feb 2010 16:50

image matrix
Hi everyone, Is there ant command in MATLAB to select a matrix of pixels from a whole image. For example, i want only the first 3*3 pixels, then the next 3*3 and so on. Is there a way I can do it? Thanx in advance. ... 12 Feb 2010 17:57

Extract the portion from image
Hi... I want to extract some specific portion from the image. I tried but unable to do. Can any one help me. Here is my code; %% Blobs analysis [Ilabel num] = bwlabel(Image); Iprops = regionprops(Ilabel); Ibox = [Iprops.BoundingBox]; Ibox = reshape(Ibox,[4, num]); %% Plot the Object Location hol... 13 Feb 2010 03:52

Minimizing an Integral function
I am trying to follow this thread here: http://mathworks.com/matlabcentral/newsreader/view_thread/86473 I have tried both the techniques outlined there to run that example (on MATLAB 7.6.0 R2008a) but whatever I try, I keep getting this error: [x,fval] = fminbnd(@tcf, -100, 100, [], a, b); ??? Undefined func... 15 Feb 2010 03:15

Input a few vectors in order to generate a "Vector Field"
I am trying to use a few vectors (between 2 and 36) to generate an estimate of the entire vector field in 2D. That is I have the vector magnitude, direction & origin of several vectors and I would like to generate the entire 2D vector field. Any examples or ideas on how to get this done? ... 19 Feb 2010 17:44

Input a few vectors in order to generate a "Vector Field"
I am trying to use a few vectors (between 2 and 36) to generate an estimate of the entire vector field in 2D. That is I have the vector magnitude, direction & origin of several vectors and I would like to generate the entire 2D vector field. Any examples or ideas on how to get this done? ... 12 Feb 2010 14:35

Division of positive integers
Hello, I have two variables i and j and they are always positive. j is equal to the result of the division of any positive number with i. Example: i=15, for a random number 42 j=42/i =2.8 however I want j to be equal to 2. So, for every division of i with a random positive number, I want j to take the value of... 12 Feb 2010 14:35

wavelet packet decomposition..
but i need this packet decomposition, which should give us a transformed signal... its here http://en.wikipedia.org/wiki/Wavelet_packet_decomposition as i've seen your earlier comments, you can figure it out. ... 19 Feb 2010 21:05