Matlab

mmreader large videos
Hi! I have big video files and load the frames via the mmreader function. The problem is, if I want to load frame number 5000 of the video (frame=read(readerObj,5000)), this takes over one minute. If I want to load the first frame of the video its very fast. How can I get access to frames at the end of the video wit... 24 Jul 2010 06:56

PCA...guys urgent help
Hey guys hi to all...I need urgent help here...I have two inputs x and y please tell me 1) How to generate a feature vector at first? what is the command in matlab? 2) How to show the direction of the principal component? Plot a line between origin and the principal eigen vector. 3) How to draw projections of the p... 23 Jul 2010 10:16

Vectorization help
I have translated a program from Fortran to MATLAB with the aim of speeding it up using vectorization, but I'm needing a little help to get it running smoothly. It runs OK with scalars, but there are a few issues with vectorization. First, this code snippet works, but is there a way of doing it without the loop? ... 23 Jul 2010 04:51

ginput, MatLAB GUI
When I select points in an image, I would like to drag the image and select the points, but if I drag the image, I couldn't continue with ginput I need a solution for that for example say I would like to select 10 points by using ginput. after selecting 5 points I would like to drag the image and then would like ... 23 Jul 2010 04:51

Find position of number in matrix
Given a matrix m, where m=ones(y,x). let us have a random integer, w, be generated from the interval 1 to y*x ¿How can i determine the [col row] position the element m(w)? ... 24 Jul 2010 14:29

cell array
Hi I have a cell array which contains TL4{:} ans = minimum and maximum node voltages at dc solution ans = 0.0000000e+00 7.6815589e-08 ans = 0.0000000e+00 6.5246487e-15 ans = 0.0000000e+00 1.8003592e-14 ans = 0.0000000e+00 1.8323368e-06 ans = 0.0000... 23 Jul 2010 03:47

Facial Expression Recognition using Back propagation neural network
We are asked to do a facial expression recognition system that uses back propagation neural network. I am not really familiar with neural networks and how could i use matlab to implement facial expression recognition. Does anyone have a source code for back propagation?? and also, how would i be able to apply it on... 24 Jul 2010 06:56

How to perform Maximization under non-linear constraints
Hi, I have been working on a problem for sometime now and not been successful. I need to maximize a particular function under some non-linear constraints. I am using fmincon for this purpose. The procedure followed is as below, and have the file names same as what I have been using. Script (*.m)-> 1. OPTIMIZE: ... 23 Jul 2010 00:34

Removing high frequency after FFT
X=fft(X) (so i have frequency from 0:N-1) How can i remove high frequency from the spectrum ! Assuming X is a row vector of 512 samples.. which mean I have 256 negative samples and 256 positive samples.. What should i do to make it band limited to say suppose 20% of samples......How can i remove the columns from ... 23 Jul 2010 00:34

Simulink Model & parameters
Dear all, I'm trying to pass parameters to a standalone file created by rtwbuild. The problem is: Most of the blocks that I used in my model come from Simulink's library (Bernoulli Binary Generator, AWGN channel, etc...) and in these blocks the parameters were not declared tunable. Due to this, they can not app... 22 Jul 2010 23:28