Math Forum / Math Software / MATLAB / July 2008

Whenever I open Matlab (2008a) I get a message in the
window that says:
" Warning: Executing startup failed in matlabrc.
This indicates a potentially serious problem in your MATLAB

I am new to matlab and I am using simpower to workout a
simple electrical circuit.  I have created a new file and
in which I have used electrical source:voltage source and
a scope from simulink.

I have a Simulink model and needs to solve a cubic equation
(Val der Waals equation solving for number of moles), take
one of the roots and feed it to the next simulink block.  
So far the cubic function yields one real and two imaginary

Hello again guys,
Anyone knows how to create and update a matrix or vector
using GUI ??
Thanks, looking foward for answers...

Could you guys help me to figure out how can I plot (in GUI)
some data points inserted in a edit box (or table) after
confirm by pushing a button??
I wanna build a GUI that I can insert data point and confirm

Where can one find the limitations of the student version
of Matlab?  Are there memory limits in the student version
of matlab R2007a, on the Mac?
Please just reply here, or remove 2 of the 5's (only use

To begin, I fear that my question shows a complete lack of
understanding of the mathematics behind the problem, but I
guess that is why I am witting to this forum.  
I am attempting to solve for the fields inside periodic

I have a known function F(x,y), I know that the equation
F(x,y)=0 determines a closed curve in x-y plane. How do I
plot it in Matlab?
For instance, F(x,y)=x^2+y^2-4. How to plot curve x^2+y^2=4

i am trying to generate an arbitrary number of random variables on
some specified interlave [a,b]
where a = 1e-5 and b = 1e-1
the suggested method from matlab:

Ok, I give up...
I can't even begin to list all the dozens of things I've
tried to make this work, but this problem is fighting back
like I killed its pet hamster.

I am using Matlab's simulated annealing functionality
(simulannealbnd) to optimize a custom function, with the
objective of locating the 'variable' or 'parameter' (vector)
that results in the function value minima.  

I have a signal x=(t>=-1)-(t>=1) which is rect(t) signal. I
tried to use:
X=fft(x);
plot(w,X)

Hi, I have these two vectors: lat (of size 31x1) and lon
(of size 53x1). I also have the data (of size 53x31).
I need to do some interpolation of this data for this I do
the following:

function y=Sample(subjectName)
white= [255 255 255];
mainBGC= white;
whichScreen= 0;  

I have another problem about read data using mexfunction. I have data as
part_coords.in file and I need to read these data using f90 mexfunction. How
should I do?
My data have 4 columns and user-defined row. I already did like this