Math Forum / Math Software / MATLAB / July 2008

Can anyone suggest a better way to do the following?  I
want a pixel list (x,y), not linear indices, of a region in
an image specified by a bounding box ... Below is a for-
loop sort of brute force approach, but I get the impression

many languages has functions to determine wich is the type
of a given object. For instance, in Python I have `type`

<type 'list'>

I am trying to solve a parabolic PDE with a variable
cofficient.
This is the form of my PDE:
(du/dt)=A(t,x)*(d^2 u/ dx^2)+ b*(du/dx)+c*u

There used to be a function called mmcxy that returned the
x-y coordinates of a mouse.  Is there a new function that
does the same thing or do I have to write one on my own?
Thank you

Is there a way to save a cell array to a text file?

I am new in Matlab figures.
I would like to plot gray-scale 3D graph by using the  
following  commands:
 deltax=20/150;

Say pieces on a board, make each piece a pair with another piece.
like...

I use 'mxCopyPtrToCharacter' to copy a string (5
characters) from Matlab to Fortran, but it can only copy
the first character of the string. Could anyone give some
suggestion?

I want to create a matrix of dimensions m x n with m = 2000
and n = 4000. How can i do it without having to write whole
of it manually. Please help me out with this.

I am writing a script that needs to know if the current
user has permission to write to a particular directory.
I am using "fileattrib" to determine owner, group, world
permissions for the directory, but I am stuck on

I am sure this must be a simple thing, but it is doing my
head in!!! imag and real don't work for me see below:

??? Subscript indices must either be real positive integers

I have a matrix of size [1,16,50] and want to find the
positions of the non-zero and zero elements within.
I have been using find but this only either gives linear
indices or row and column indices. I want it to include page

I am trying to use the deploy tool to create a stand alone
application.  I follow the steps i have seen on the matlab
tutorials.  I see in one of the tutorials the instructor
can click on the EXE file after matlab Builds the project.  

Hello, I am using a function that returns a struct array.  But I have no idea how to get at what is inside.  Here is what matlab tells me if I type the variable name, and do a "whos" on it:
-----------------------------------------------------
EDU>> OPTS
OPTS =

Hello, I'm trying to implement a customized Power Spectral
Density (PSD) function in a Simulink model. Is there any
way to do it? Thank you.