Matlab

How can i crop a circle from an image?
Hello everyone, I checked the imcrop function and its quite straight forward to use for shapes such as rectangle.. My question is suppose I have an image, a particular centre and radius iand would like to crop this circle from the image. Any sugestions please... I checked the thread http://www.mathworks.c... 21 Feb 2010 07:04

2D gaussian fit of image
"Steffen " <rileksn(a)gmail.com> wrote in message <fqj32l$m4n$1(a)fred.mathworks.com>... HI there, I?d like to fit a gaussian to a bead image representing the PSF of my microscope. The ultimate goal is to define the 'exact' position of the peak in x and y. I need to fit a gaussian to the image rather tha... 14 Feb 2010 18:30

cholesky decomposition avoiding square root
matlab function chol( ) does Cholesky decomposition of the form: LL* An alternative for of Cholesky decomposition is LDL' (http:// en.wikipedia.org/wiki/Cholesky_decomposition) Does anyone know if matlab has a built-in routine for the later form? ... 15 Feb 2010 06:30

differentiating a piecewise function
Hi all, I have been using Mathematica for a while and I just started using Matlab. Needless to say the transition is quite painful. I need to differentiate a piecewise function (which I have created using piecewise.m), but I cannot be able to do it. So how can one differentiate a simple function like y = sin(x) f... 14 Feb 2010 17:23

plotYY - the most annoying command in the world
Hi, Hopefully someone can help me here because i'm lost for fixing this. I'm trying to plot two time series at shared x-values but with different scales on the y-axis. I extract both time series from a financial time series object since plotyy doesn't like this construct. My problem is that I can't get the date... 24 Feb 2010 16:33

Applying a function to a matrix
Hey everybody, The problem I have has us create a 500ft by 500ft are in 5ft by 5ft squares, making a matrix that is 101 by 101. They also give a point in the square and we have to find the radius from every point in the area. The point being 250.5, 250.5. So I was having trouble with finding the radius at every poin... 14 Feb 2010 16:16

Help! meshc(x,y,z,v) plot is ignoring the "v" vector
Hey everyone. I was hoping you could help me with getting the contour lines in a simple "v" vector to plot. Below is the code I'm using. Instead of following the level set values in v, meshc just throws it out and plots the default level sets. Also, the function is not plotted above these default contour lines. What is... 14 Feb 2010 15:09

please what is the name of this method
"Bruno Luong" <b.luong(a)fogale.findmycountry> wrote in message <gkqro5$7qn$1(a)fred.mathworks.com>... n=100; l=1:n; isprime=true(1,n); isprime(1)=false; p=2; isprime(2*p:p:end)=false; p=3; while p^2<=n while ~isprime(p) && p^2<=n p=p+1; end if ~isprime(p) b... 14 Feb 2010 15:09

please help just to verify
% sum[(-1)^i* factorial(M-1,i)* sum ( prod(k-m) )] % i=0->M-1 j=0toM-1,j<>i k=0toM-1,k<>j % sum [of sum of (prod)] % for fixed M; m varies from 0 to M-1; % example M=5 % i=0; k=0,1,2,3,4; m=1 % (-1)^i*bin(4,i)*sum( j=0 (0-m)(1-m)... 14 Feb 2010 15:09

meshc(x,y,z,v) plot is ignoring the "v" vector
Hey everyone. I'm having some trouble with getting the contour lines in a simple "v" vector to plot. Below is the code I'm using. Instead of following the values in v, meshc just throws it out and plots the default points. Also, the function is not plotted above these default contour lines. What is incorrect? [... 14 Feb 2010 14:01