Math Forum / Math Software / MATLAB

I'm curious what the exact difference between QuadProg and FMINCON are when both are  using an Active-Set algorithm?
From my tests, i find quadprog runs faster and tends to be more accurate with care taken to make sure tolerances are the same (etc).
Cheers, Lyle

I have two vectors like this:
lon = [-125.2 -124.3 -85.6]
lat = [6 10.2  50.4]
I need to convert these to cartesian coordinates. Any suggestions?

i'm a beginner in matlab.I need to create distribution function of a meixner distribution:
function y=meixner(x,a,b,d,m)
x=x(:);
n=length(x);

The story below happens on Earth surface.
There is an arc of a great circle (AB), the two endpoints of which are placed at (latA,lonA) and (latB, lonB). Beside, there is a quadrangle. The latitude and longitude of the four vertices (V1,V2,V3,V4) of the quadrangle are also known. ...

I have an image and I only want the black pixels. In the end, I need a binary image with all the black pixels in white and everything else black. What I've been doing is something like image_new = image < 40, but this is not very robust. I want my code to work on any image I load ...

I have a question about matrix manipulation, I am not very familiar with matlab code and I am trying to expand a matrix by repeating the numbers.
Here is the example.
I have a 4 by 4 matrix as follow:
0 5 2 3

I want to constrain the crossCorr function to return parameters/solutions between 0-1, because a priori I do not expect any negative relationships.
Is there an easy way to do this that I am overlooking, thanks.

I'm very new (like a few days) to MatLab, so please bear with me.  I want to use AccumArray to aggregate some data.  Suppose I have a 30x1 data source which is effectively grouped 1, 2,...,10, 1, 2,..., 10, 1, 2,...,10.  I can then use something like
indices = repmat([[1:10]', ...

I'm stuck with the following problem:
I have a large matrix R, say of size 2000 by 500, and a threshold value k. For each row, I seek the numbers of elements that are below k. Hence, the output would be a 2000 by 1 vector.
So far, I've used "Q  = SUM( R < k , 2 )", which proved to ...

the only way i can think is:
'sum(find(a==B))==0'
but i guess there should be a simple command,
isn't there?

Hello, recently I began to use r2009a in XP sp2 ...
When I try to run the script directly from the editor, a window asking to change current directory or add path appear. No matter which option I take, an error message appear. Any one could tellme what happen? and how to resolve ...

Good evening, everyone.
I am using Matlab/Simulink R2009a.
I am trying to use simulink to simulate the PMSM to act as a generator and connected to the resistors.
The figures of the connection and the results are shown as this link below:

I have this problem: I have 27 figures and I need to print
them to .pdf file, 9 figures on 3 pages. I know, how to
print on one page with command "print", but I can't find,
how to print on more pages. Can anyone help me?

I have the following situation:
- read an image (0..255 range); cast it to double precision;
- compute its gradient (dIdx and dIdy, which obviously will contain both positive and negative entries)
- try to add noise to the derivatives using imnoise function;

I came across the "brain teaser" of finding the best approximation of pi by dividing one 9-digit number by another 9-digit number.  Both numbers contain 1 through 9 once.
I found a very close approximation by hand (728691345 / 231948765 = 3.141604763) but I want to know if there ...