**matrix in a matrix**hallo there.
I want to put a matrix that is 128X128 in a matrix that is 512X512 ( ones(512) ).
what I want to do is to have the white image and above to put the second image ( a letter, A for example).
I cant multiply cause they dont have the same dimensions.
any ideas??
thanks in advance
"th " <THOMITSU@YAHOO.COM> wrote in message <hsjabs$bbc$1@fred.mathworks.com>...
> hallo there.
>
> I want to put a matrix that is 128X128 in a matrix that is 512X512 ( ones(512) ).
>
> what I want to do is to have the white image and above ...

**Matrix in a matrix?**Hi to all,
I've encountered a problem using Matlab. As I'm not very familiar
with matlab, there are functions which I have not used before.
What I would like to know, if there is a way to express a matrix
within a matrix. For example,
R= [ r1 r2 r3 ... rn]
where rn=[xn yn tn]
and xn, yn, tn are column of numbers.
I used the following code below to express the numbers in rn as
coloumns for easy referencing.
xn=r(:,1); %represents the columns in the matrix
yn=r(:,2);
tn=r(:,3);
My objective is to be able to retrieve information in the matrix
easily and compare their values. Meani...

**matrix in matrix (?)**Hi, I need help!
I want to construct a matrix 10x10 where every element is a matrix
?x2.
After, I need to extract the ?x2 matrix by the 10x10.
how to make that?
mirus wrote:
> Hi, I need help!
>
> I want to construct a matrix 10x10 where every element is a matrix
> ?x2.
>
> After, I need to extract the ?x2 matrix by the 10x10.
>
> how to make that?
have a look at cell arrays. they provide the possibility to store
arbitrary data in an array like fashion.
michael
Michael Wild wrote:
> mirus wrote:
>> Hi, I need help!
>>
>> I want to constru...

**Matrix of matrix**Hi everbody.
First of all, I apologize for my English, so please be indulgent with me if my sentences are not grammatically correct.
I have some trouble with MATLAB.
I have some data in txt files that I catch like that :
MFS93A1 = textread('Z:/Fichiers/MFS93.A1.txt','','headerlines',1);
MFS93B1 = textread('Z:/Fichiers/MFS93.B1.txt','','headerlines',1);
MFM77A1 = textread('Z:/Fichiers/MFM77.A1.txt','','headerlines',1);
MFM77C1 = textread('Z:/Fichiers/MFM77.C1.txt','','headerlines',1);
Then, in or...

**Matrix Exponential**Does IDL have, or has anyone written, a matrix exponential function
similar to the matlab expm()
http://www.mathworks.com/access/helpdesk/help/techdoc/index.html?/access/helpdesk/help/techdoc/ref/expm.html
On Thu, 5 Nov 2009 12:20:47 -0800 (PST), Dave L <dave.lenar@gmail.com>
wrote:
>Does IDL have, or has anyone written, a matrix exponential function
>similar to the matlab expm()
> http://www.mathworks.com/access/helpdesk/help/techdoc/index.html?/access/helpdesk/help/techdoc/ref/expm.html
It seems you can do this by calculating eigenvectors and eigenvalues.
Look in the help ...

**Request Fortran code for Matrix exponential for a real matrix, with accuracy estimate**Hello,
I was looking for an open source Fortran code to compute Matrix
exponential for a real matrix, with accuracy estimate, something like
http://www.slicot.org/shared/doc/MB05OD.html. I tried to search Scilab
but was not successful.
Thanks for any hint.
Zhu
On 11/12/2011 2:41 PM, Zhu Wang wrote:
> Hello,
>
> I was looking for an open source Fortran code to compute Matrix
> exponential for a real matrix, with accuracy estimate, something like
> http://www.slicot.org/shared/doc/MB05OD.html. I tried to search Scilab
> but was not successful.
>
> Thanks for any hint....

**Exponential Matrix integration**Let B be a nonsingular nxn matrix. I want to integrate the function:
f(t) from 0 to T, where f(t)=exp(Bt)*exp(Bt)'. Can somebody help me?
Thanks.
is t symbolic, or numerical?
numnerical integration?
Cheers...
In article <jlhee8z4ftbh@legacy>,
juliocacho@hotmail.com (Julio) writes:
>Let B be a nonsingular nxn matrix. I want to integrate the function:
>f(t) from 0 to T, where f(t)=exp(Bt)*exp(Bt)'. Can somebody help me?
>Thanks.
>
If B is diagonalizable then
B=T*\Lambda*inv(T) with \Lambda the diagonal matrix of the eigenvalues
and
exp(Bt) = T*d...

**MATRIX LOGARITHM (and EXPONENTIAL)**Just a quick question. Does IDL have a similar command to the popular
MATLAB logm and expm so that I can take the matrix logarithm (and
exponential)? I understand that ALOG and EXP will not function in this
sense.
Thank you,
teddy
On Jan 27, 7:41=A0pm, teddyallen <teddyal...@yahoo.com> wrote:
> Just a quick question. Does IDL have a similar command to the popular
> MATLAB logm and expm so that I can take the matrix logarithm (and
> exponential)? I understand that ALOG and EXP will not function in this
> sense.
Can you explain what matrix log and exp are?
On Ja...

**Fast Matrix Exponential**Hi All,
I was wondering if anyone out there knows a fast alternative to the matrix exponential function expm. Perhaps there is a mex file out there somewhere? The matrix I am considering does not have any special form, except that all its entries are real numbers. I have considered the expokit package, but was wondering if there is anything faster out there.
Thank you very much,
--Raul Gonzalez
"Raul " <ragonzal@alum.mit.edu> wrote in message <hrmaop$at$1@fred.mathworks.com>...
> Hi All,
>
> I was wondering if anyone out there knows a fast alternat...

**Symbolic matrix exponentiation**Hello,
I am attempting to calculate the general form of an equation using symbolic math in the example below. This example, as shown, runs quickly and the result has already been very useful to me.
I am hoping to extend this example to the generalized case. If I allow one more parameter to be free, for example by removing a = 1, then calculating the expm never finishes. The problem goes from being solved in a few seconds to not completing within days.
Ideally I would like to allow all parameters to be free, including a, c, d, and f. Is there a trick that will make this exponentiat...

**Matrix exponentiation in FORTRAN**Hi,
I hope I've come to the right place - please redirect me if there's a
more appropriate forum to be asking these questions.
I am trying to figure out how to compute the exponential of a matrix
in FORTRAN - something similar to expm used in MATLAB, and MatrixExp
in Mathematica. I've gone through LAPACK's online documentation but
couldn't find an answer. Is there some way of getting this done? I'd
appreciate your kind help with this.
Maayan.
Hi,
As if by magic, Maayan appeared !
> Hi,
>
> I hope I've come to the right place - please redirect me if...

**exponential of matrix in fortran90**hi,
I'm looking for a subroutine for fortran90 that could compute
exponential of a matrix?
Is there any subroutine?
I read "Nineteen Dubious Ways to Compute the Exponential of a
Matrix",but I don't know which way is better?
could you help me?
thanks,
Elaheh
In article <d8a80ca7-eb2d-4d5c-9c8f-70964ede639d@h11g2000yqb.googlegroups.com>,
<elaheh.adibi@gmail.com> wrote:
>hi,
>I'm looking for a subroutine for fortran90 that could compute
>exponential of a matrix?
>Is there any subroutine?
>I read "Nineteen Dubious Ways to Compute the Exp...

**Matrix Exponential in Labview**Anybody know how to compute a 'Matrix Exponential' in labview? Either
in the base package or an add-on toolkit. For a an explanation of the
matrix exponential, see:
http://zone.ni.com/devzone/conceptd.nsf/webmain/0CF7E24984DA7D9586256D720054FC07?opendocument
Which the only reference I can find on the web site.
Thanks, Ian Wall
I quickly looked at the document and I do not think you compute the
matrix exponential.
It appears to be an identity. It just says that a matrix to some
power can be expressed as an infinite sum. You can use the two
interchangably in your calculations. For ...

**matrix exponential expm**Hello.
I'm using expm function to solve differential systems of equations for some simulations. It worked fine before for an another program. Now I have the problem that the result matrix contains NaN coefficients or huge coefficients. My guess is that the input matrix isn't well scaled (some coefficients are big others close to zero). But what could I do with that? My idea is to change the units of physical parameters but I just wonder if there is some method provided by Matlab to deal with such problem.
Please help If you can.
Alexandru
"alexandru cornogolub" &...

**insert a matrix into matrix**hello, new to all this so excuse my ignorance
lets say i have
x = 1 2 3 4
which i convert to column vector
x=
1
2
3
4
now i have a, created from the lengh of x in this case 4, and any
value, lets say 4, so
a=
0 0 0 0
0 0 0 0
0 0 0 0
0 0 0 0
now i want to insert x into a 4 times, so that
a=
1 1 1 1
2 2 2 2
3 3 3 3
4 4 4 4
but i want to do this without a loop
i can replace it with numbers
using
a(,:i)=x
where i = 1 to 4 in this case, but i have to use a loop for that,
did i explain that ok, can anyone help?
cheeseboy
On Fri, 19 Nov 2004 20:47:25 -0500, cheeseboy wrote:
> hello...

**Copy from matrix to matrix...How?**Dear friends,
if the matrix U1 equal to:
U1=[1,1,1,1;
0,0,0,0;
0,0,0,0
]
and the second matrix U2 equal to:
U2=[0,0,0,0;
2,2,2,2;
0,0,0,0
]
how can I creat the third matrix whic is equal to:
U3=[1,1,1,1;
2,2,2,2;
0,0,0,0
]
Please could you change on my code to be right?
This is the code:
for j=1:10
for i=1:12
U1(i,j)=U2(i,j);
end
end
waiting for your solution.......Thanks
You can just write:
U3=U1+U2
alfann <alfann.net@hotmail.com> wrote in message <2072829264.305125.126762...

**Exponential of a matrix indexed by a parameter**I have a matrix which is indexed by a parameter, something like:
2-x 3
4 1+x
where x is a vector; so there is one matrix corresponding to each
value of x. I want to take the matrix exponential of this. Is there a
way to do it without using a "for" loop over all the values of x?
Thanks,
Mauro
Mauro <msmscarlatti@googlemail.com> wrote in message <d1f6d508-89a6-4742-83fe-9a68d7ebe393@e5g2000yqn.googlegroups.com>...
> I have a matrix which is indexed by a parameter, something like:
>
> 2-x 3
> 4 1+x
>
> where x is a...

**Matrix filtering by other matrix**Hi all,
I have two vectors, one with data, and one with 0 /1 values that says which items on the first vector are valid. I need to create a third vector that is built only from the valid items on the first vector. Is there a single command that does that (it's easy to do it iteratively, but I guess that the performance are bad doing it like that)
thanks
Yoav
"Yoav Rubin" <yoavrubin@hotmail.com> wrote in message <gri62q$hhd$1@fred.mathworks.com>...
> Hi all,
>
> I have two vectors, one with data, and one with 0 /1 values that says which items on the fi...

**Matrix Exponential m-file**Hello. I am trying to compare the performance of the matlab matrix
exponential (expm) command to a custom method, but I can't get apples
to apples since expm is a build-in command and runs much faster. Is
their any way to get a m-file for the expm command.
I know I could make one from consulting the literature, but would
really like to make a quick comparison if I can find an
implementation that uses a non-compiled function.
Regards,
Tim
try expmdemo1
---Bob.
"Tim Booher" <timothy.booher@afit.edu> wrote in message
news:ef24d4a.-1@webx.raydaftYaTP...
> Hello. I am ...

**Matrix in a Matrix #2**Say for instance: A = [1 2; 3 4; 5 6];
B = [2 1; 3 2; 6 5];
Is there anyway that I can say:
C(1,1) = A;
C(2,1) = B;
etc.
Or is it possible to store a matrix as a single element of another?
Thanks.
"Dan" <danrajjj007@hotmail.com> wrote in message
news:eed05cf.-1@webx.raydaftYaTP...
> Say for instance: A = [1 2; 3 4; 5 6];
> B = [2 1; 3 2; 6 5];
>
> Is there anyway that I can say:
>
> C(1,1) = A;
> C(2,1) = B;
> etc.
>
> Or is it possible to store a matrix as a single element of another?
>
> Thanks.
Ken Davis just answered th...

**Integrating matrix exponential function**Hi all,
I have H = H0 + H1*cos(2*pi*Freq*t) with Hermitian matrices
H0 and H1 (size between 3 and 160), and I need to integrate
the function expm(-2i*pi*H(t)*t) over one period [0,1/Freq[.
My implementation sums over ~500 knots using the function
below. Although it is the bottleneck in my overall code, I can't
see a way to make it faster or more accurate with fewer knots.
Does anybody have an idea how to speed it up? Is there a possible
algorithmic improvement?
Thanks, sTefan
%--------------------------------------------------------
function U = oneperiod(H0,H1,Freq,nInt...

**indexing a matrix with a matrix**I'm trying to work out the syntax for indexing a 2D matrix with a
matrix of coordinates.
I know how to do the 1D version. If I have a 1D vector 'A' and a
vector 'B' that contains index values; then I can do A(B) and it gives
a vector the same length as 'B' with the values of 'A' that correspond
to the indexes in 'B'.
I can't seem to work out the 2D version. 'A' is now a 2D matrix. 'B'
is now a matrix with 2 columns - 1st column is x values, second column
is y values. So each row uniquely indexes a value in 'A'. But how do...

**Comparing matrix to matrix**Hi all experienced matlab user,
Here is my problem:
I want to make it faster, so I don't want to use any for loop..(Since I want to compete with CPlex..I hope it is feasible :( )
Description:
Input:
A =[1 6 3; 2 4 6;4 5 3];
B = [1 3 5;2 7 4];
Output:
[1 6 3; 4 5 3; 1 3 5]
(Order is not important)
**My goal is merging A and B and eliminate the non-dominated vector**
i.e. A(2,:) and B(2,:)
(The elements of [1 3 5] are all smaller than [2 4 6], so [2 4 6] is dominated by [1 3 5], similar to [2 7 4], which is dominated by [1 6 3])
Here is my current MATLAB Code:
...

**matrix of matrix #2**i have many matrixs to dispose on diagonal of a new matrix.
X Y Z matrix N*M
A=X
Y
Z
can you help me please?
thanks in any way
Bye
Imma
imma wrote:
>
>
> i have many matrixs to dispose on diagonal of a new matrix.
> X Y Z matrix N*M
> A=X
> Y
> Z
> can you help me please?
> thanks in any way
> Bye
> Imma
Can you give a small example?
At least, take a look at <diag> or <blkdiag>
hth
Jos
...