Matlab

Using FFTW in mex file
Hi ! In using mex file i am a novice ! So here is a question I have a mex file which uses FFTW ..FFTW is installed on my server in /user/local/lib and /usr/local/include .. so my file is example.c which has function which uses this libray ! so wont simple so mex example.c should make gcc compiler to work ! or... 29 Jul 2010 08:34

noise regions in an image
i am working on LSB based image stegnography but i want insert my data in image where noise is more or there are more color variations in that region can any1 help me in that ... 16 Jul 2010 02:19

diff and gradient function, derivative of a vector
Hi, I am given a vector say A= [.....................] that describe a function say f(x). Now, I have to calculate the derivetive d(A)/d(x). x = 1: N and is equally spaced with any equal width (0.1 or 0.5 or 1 or anything). I was using both diff (A) gradient (A) however, the derivative value I get using di... 16 Jul 2010 12:06

reassigning values of elements in matrix
I need to re-assign the elements in a matrix to another set of values. The simplest, say, is to assign by order stats. For example, if I have a = [ 1 3 4 6 3 1 4 ]; By order stats, I only have 4 unique elements 1 3 4 6. I would like to re-number the elements to 1 2 3 4. Currently I am using unique: ... 16 Jul 2010 01:15

Symbols for x and y labels
Hi, I would like to name the x and y labels using the differential symbol, for example, x2dot ( read as x double dot), i.e double differential of x. Also, I would like to print differential equation on a plot using 'text' function. Any help would be greatly appreciated. Thanks, Sami ... 16 Jul 2010 11:00

S-Function
Dear Sir or Madam, I am trying to run a Simulink file with an S-Function. The Simulink file is supposed to read/capture data from some EEG channels, to do some calculations on the data (independent component analysis) and output the result. All these calculation is going to be on-line or in real-time. I have to... 16 Jul 2010 00:09

avifile getframe screensaver problems
Hi, I'm running MATLAB R2009a on 64-bit Windows. I'm trying to create an AVI file from some grayscale images, which I've displayed with imshow() and then have added a few white symbols with plot(). As far as I know, the only codecs I have available are 'RLE', 'MSVC' and 'IYUV'. I have been able to create a movie ... 16 Jul 2010 20:57

lsqnonlin
Hi, Can anyone explain what the termination flags 2 and 3 mean in the function lsqnonlin? Is there a place where to get more details about this routine? Matlab only says that the "Change in the residual smaller than the specified tolerance" . Is it good or bad? Thanks ... 16 Jul 2010 08:47

How to select and sum elements in an array fast?
I have two vectors -- one contains the values, and the other is the corresponding index. For example A = [0.1 0.3 0.2 0.5 .... ] B = [1 3 4 2 1 ] The have the same length. I need to select the elements in A with the same index in B, and sum them. For each index in B, the numbers of the corresponding eleme... 16 Jul 2010 00:09

Simscape power converter model
Hello, I am trying to build a power converter model in simscape. When running the simulation, I receive this error message: "Number of variables exceeds number of equations. Check for missing reference node." I know that there is a problem with the solver configuration, but have no idea how to go about solving the p... 19 Jul 2010 10:12