Matlab Forum RSS Feed

Equation with 3 unknowns. how do i find the maximum solution?

Wed, 08 Feb 2012 16:39:24 -0800

Hello,

Im stuck in matlab, i have an equation with 3 unknowns. how can i get the maximum answer possible? Is there a way with a 3D graph??

Equation:

F = ( sqrt((b^2 + c^2) -(2b c cos(y))) x M ) / (b c sin(y))

I have M as an answer in terms of y. its <1 x 111 double >

I have the following limits: 0<b<6 , 0<c<6 and 0<y<110

I am looking to get the maximum F, any help is appreciated thanks!

How to find a complex root from the determinate of a matrix? [URGENT]

Tue, 07 Feb 2012 06:34:04 -0800

Hi everyone,

Im having a trouble that can be described into two steps:

1)Im having a square complex matrix with unknown x.

2)I need to find x such that the determine of the matrix is zero.

Im trying to separate the solution into real and imag part and solve:

Function detM = detMcal(x,a,delta,L)

complexX = complex(x(1:2:end), x(2:2:end));

complexY = det(Matrix(x,a,delta,L))

detM = [real(complexY); imag(complexY)];

end

*and*

x = fsolve(@(x) detMcal(x,a,delta,L),[1,1]);

solution = complex(x(1:2:end), x(2:2:end))

But the program is not working. Is my code wrong or are there any better

method?

Many Thanks.

How to find a complex root from the determinate of a matrix? [URGENT]

Tue, 07 Feb 2012 06:32:06 -0800

Matlab Parallel Programming help needed!!!

Sun, 05 Feb 2012 14:48:34 -0800

Hi, I am a noob in matlab anf I am trying to parallelize loading of an array file.

So suppose the array size is X by Y. I would like to load this file to "n" matlab workers giving X/n by Y to 1st worker and X/n by Y to another and so on.... Does anyone know how can I achieve that since the file is too large and load of that file in a distributed way can save me loads of time.

So I am trying something like this for my application:

1. Start n worker nodes
2. load X/n by Y data on each worker node
3. Output = function (X/n, Y)
4. Final Output = Gather (Output)
5. Stop all worker nodes.

Do let me know if you can help me in any possible way.

Thanks

Very urgent please help

Sun, 05 Feb 2012 00:43:25 -0800

Hi Everybody,
I am now facing problems with solving integration by matlab. these equations are given below-

X(t)=integration((Vx(t)+Vy(t))/2*cos(theta)dt)

where Vx,Vy and theta are functions of time(t).
the limit is to to t1.

I am having problem with that i can not define Vx,Vy and theta as a function of t, so that i can integrate this whole equation with time derivative.

please help !!!!!

ssor

Fri, 03 Feb 2012 10:08:06 -0800

can someone help me code ssor in matlab please

ssor

Fri, 03 Feb 2012 10:06:13 -0800

can someone help me code ssor in matlab please

help with vectors

Wed, 01 Feb 2012 17:25:49 -0800

Hello all. I am trying to write a function to determine if a number is prime without using a for loop. More specifically, the function needs to be "vectorized". I am able to write a function to determine if any number is prime using a for loop, but I am unable to figure out how to write a function that will determine if a number is prime by using a function without a for loop.

Any help would be greatly appreciated.

Here is what I have tried, but I cannot get my output to tell me anything (i.e. it does not return any 1s or 0s):

function [noloop]=isPrime_noloop(n)
n = ones(1,40000000);
j = 2;
while(j<(40000000/2))
n((j*2):j:end) = 0;
j = j+1;
while(n(j)==0) % find next prime
j = j+1; end
end

Help on a Matlab/Structural problem

Wed, 01 Feb 2012 16:38:14 -0800

Can anyone do this for me with Matlab? I have no clue how to go about it. The directions are on the attachment. Its really confusing me and I'm not the best with Matlab in general.

thanks a lot!

Attachment: CE305.jpg (704646 bytes | downloaded 8 times)

HELP! How to do this Function

Wed, 01 Feb 2012 12:42:13 -0800

Guys
Please Help me i really noob in matlab
even i can do this simple thing

I have to plot this function

x=t*exp(-2*t)

from t = 0 till 10

the first thing i do is i give the t value using this command

t=0:0.01:10;

then i give matlab the x function

x=t*exp(-2*t)

matlab give me this feedback

Error using *
Inner matrix dimensions must agree.

then i realize when i give t a value matlab recognize it as matrix
that means exp(-2*t) also a matrix

so i can't times the matrix with unfit dimensions

then my question how is the proper way to resolve this function in matlab

please i really need your help

thank you

HELP! How to do this Function

Wed, 01 Feb 2012 12:38:42 -0800

Machine vision toolbox compatibility

Wed, 01 Feb 2012 04:47:14 -0800

Hey,

wondering if anyone can tell me if the machine vision toolbox is compatible with Matlab version 2007b as when i try to execute after download errors continue to pop up looking for 'rtbstartup'?? really appreciate if anyone has any info on this!!!

Machine vision toolbox compatibility

Wed, 01 Feb 2012 04:45:23 -0800

How to plot this function ?

Tue, 31 Jan 2012 10:27:56 -0800

My function is;

y(x,s)= 1-(cos[(s-1)arctan(x)]*gamma(s-1))/(1+x^2)^(s-1)/2

varible x will have range from 0 to 10. At one time the s value will be constant e.g. s = 3 but I want to change s for different values( is there any commands in matlab that will allow me to do this ?). I tried many time but can't get it.

How to plot this function ?

Tue, 31 Jan 2012 10:26:05 -0800

2D plot of a function - URGENT !!

Tue, 31 Jan 2012 10:09:08 -0800

2D plot of a function - URGENT !!

Tue, 31 Jan 2012 10:07:17 -0800

MatLab for DAQ

Mon, 30 Jan 2012 13:16:32 -0800

I am trying to use a NI-6025 controller for various testing applications at my company. Below is the code that I am trying to use for data acquisition:

ai = analoginput('nidaq','Dev1');
addchannel(ai,0);
ai;
start(ai)
wait(ai,2)
data = getdata(ai);
plot(data)

When I get to the 'start' command, however, I receive an error:

??? The hardware you are trying to use is already
reserved, either by another
object in this MATLAB session, or possibly by another
application. To unreserve
the device if held by this session of MATLAB or another
MATLAB session, delete
the object that may have it reserved, or run daqreset.
As a last resort, use
National Instrument's Measurement & Automation Explorer
to reset the device.

Error in ==> daqdevice.start at 62
start( daqgetfield(obj,'uddobject') );

I've restarted my computer to verify that nothing else could possibly be referencing the controller, and I've also verified on the Measurement and Automation Explorer that the device is free. Does anyone have any suggestions as how I could receive data from my controller? Your help is appreciated.

-Austin

MatLab for DAQ

Mon, 30 Jan 2012 13:14:42 -0800

How to show the picture in GUI

Sat, 28 Jan 2012 09:57:49 -0800

i have problem to convert the coding m.file to m.file for GUI.i cannot understand how to manage my coding in m.file without GUI to m.file in GUI. How can i view the image that i find from my file to axes that i already create to place that picture.

How to show the picture in GUI

Sat, 28 Jan 2012 09:38:14 -0800

ANN

Thu, 26 Jan 2012 06:07:26 -0800

Hi
I have been trained a neural network in Matlab.
it is training well and when I give inputs it answers well.
But when i manually solve it i can't reach the answer.
this is formula:"a1 = tansig(IW{1,1}*p1+b1)
a2 = purelin(a1*LW{2,1}+b2)"
p1 is input.
a1 is output of first layer(hidden layer) and a2 is second(output layer) one's output
b1 is bias of first layer and b2 is bias of second layer.

ANN

Thu, 26 Jan 2012 05:01:06 -0800

Hi
I have been trained a neural network in Matlab.
it is training well and when I give inputs it answers well.
But when i manually solve it i can't reach the answer.
this is formula:"a1 = tansig(IW{1,1}*p1+b1)a2 = purelin(a1*LW{2,1}+b2)"
p1 is input.
a1 is output of first layer(hidden layer) and a2 is second(output layer) one's output.
b1 is bias of first layer and b2 is bias of second layer.
a2 is output.

ANN (artificial neural network) help needed

Thu, 26 Jan 2012 04:57:39 -0800

Hi
I have been trained a neural network in Matlab.
it is training well and when I give inputs it answers well.
But when i manually solve it i can't reach the answer.
this is formula:"a1 = tansig(IW{1,1}*p1+b1)a2 = purelin(a1*LW{2,1}+b2)"
p1 is input.
a1 is output of first layer(hidden layer) and a2 is second(output layer) one's output.
b1 is bias of first layer and b2 is bias of second layer.
a2 is output.

ANN (artificial neural network) help needed

Thu, 26 Jan 2012 04:49:29 -0800

Hi
I have been trained a neural network in Matlab.
it is training well and when I give inputs it answers well.
But when i manually solve it i can't reach the answer.
this is formula:"a1 = tansig(IW{1,1}*p1+b1)
a2 = purelin(a1*LW{2,1}+b2)"
p1 is input.
a1 is output of first layer(hidden layer) and a2 is second(output layer) one's output.
b1 is bias of first layer and b2 is bias of second layer.