**how to calculate WARPING MATRIX from HOMOGRAPHY MATRIX**hi all,
my problem is: I have the HOMOGRAPHY MATRIX (size 3*3) already, and I want to calculate the WARPING MATRIX H (size N*N for N=total pixel number of superresolution image):
[LR]=DBH.[HR]+noise,
where:
[LR] size M*1, [HR] size N*1: all pixels of the images.
Anyone suggest me a solution please, this is urgent..
Thank you very much!!
...

**to find cofactor matrix of a 3x3 matrix**pls help me to find the cofactor matrix of each element in a 3x3 matrix
rony <rdmathew@gmail.com> wrote in message
<1191839021.515718.75940@o3g2000hsb.googlegroups.com>...
> pls help me to find the cofactor matrix of each element
in a 3x3 matrix
>
http://www.mathwords.com/a/adjoint.htm
rony <rdmathew@gmail.com> wrote in message
<1191839021.515718.75940@o3g2000hsb.googlegroups.com>...
> pls help me to find the cofactor matrix of each element in a 3x3 matrix
>
Not very MATLABy code and no guarantees:
function cof=cof3x3(m)
% function cof=cof3x3(m)...

**sample signal arrays into a matrix and calculate covariance matrix**i want to gather signals from different channels and put these into a
matrix which will be updated at every time step. then this matrix
should be normalized and the covariance matrix should be calculated.
then i want to calculate the eigenvalues of this latter matrix and
display them. this last part(normalize,covariance and eigenvalue) can
be done either at every time step or after a specific time interval.(i
prefer time interval because i don't need that dense information). my
main problem is to update the signal matrix. i tried to use "insert
into array" but as the matrix shoul...

**Sparse Matrix Calculation exceed full matrix times**Hi,
I've been using a solar radiation model for a while, and I'm
just looking into the possibilities of using sparse matrices
generated using quadtrees to optimise the model.
I did some quadtree decomposition on a digital elevation
model (converting the DEM to an intensity image) and the
used elevation values (plus slope, aspect etc) averaged from
the respective blocks as input to the radiation model.
now as the number of elements, e.g. the size of the matrices
is supposed to be much smaller, i was expecting the
calculation with sparse matrices to be much faster, but the
opposite is th...

**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 calculation**Folks
Just wondering if there is any libraries/routines that
can find eigenvalues and eigenvectors.
thanks for info
Hossain
Google LAPACK or BLAS or Numerical Recipe.
See, for example:
http://www.netlib.org/eispack/index.html
Skip
On Wed, 07 Dec 2005 03:55:20 GMT, Masrur Hossain <masrur@linuxbox.net> wrote:
-|Folks
-| Just wondering if there is any libraries/routines that
-|can find eigenvalues and eigenvectors.
-|
-|thanks for info
-|
-|Hossain
Herman D. Knoble <SkipKnobleLESS@SPAMpsu.DOT.edu> wrote:
> http://www.netlib.org/eispack/index.html
Very ...

**matrix calculation**Dear All,
I would appreciate any help with the following problem. I have a
vector "a" as follows:
1
2
3
4
5
;
and would like to obtain a matrix where:
-on diagonal I have ai^2 if i=j
-on off-diagonal I have either: ai*aj if 1<=abs(i-j)<=10 or: 0
So the matrix looks more or less like that:
1*1 1*2 1*3........0 0 0
2*1 2*2 2*3.. ......0 0 0
3*1 3*2 3*3..................
................. .11*11 11*12
0 0 0 .... ....12*11 12*12
Thank you!
Paul
Paul,
DATA MAT(DROP=i j);
ARRAY A [12] ;
DO i=1 TO 12;
DO j=1 TO 12;
A(j)=i*j;
IF ABS(j-i)>10 THEN A(j)=0;
END;
OU...

**Cofactor Matrix**Hello,
I am having a problem with the Cofactor matrix:
http://en.wikipedia.org/wiki/Minor_%28linear_algebra%29
My problem is that I have the cofactor matrix and I need to find the
original matrix. How can I do this?
My cofactor matrix is:
Cofactor of A = [-1 1 2; -2 1 4; 2 -1 -3]
Det(A) = |A| = 1
How can I calculate the original matrix A?
Thanks,
Miguel
On Dec 6, 12:58 am, shapper <mdmo...@gmail.com> wrote:
> Hello,
>
> I am having a problem with the Cofactor matrix:http://en.wikipedia.org/wiki/Minor_%28linear_algebra%29
>
> My problem is that I have the cofactor ma...

**How to calculate the derivative of matrix w.r.t another matrix?**Dear All
I have a problem of calculating the derivative of dxm matrix A with respect
to another dxm matrix B,
where A= [a1 a2 ... am] and B =[b1 b2 ... bm] with
ai and bj are vectors.
Actually the matrix A itself is the first order derivative
of a scalar J with respect to B, i.e., A = dJ/dB,
where a1 = dJ/db1, a2 = dJ/db1, and so on.
Now dA/dB is the second order derivative
dA/dB = dJ^2/(dBdB')
= [dJ/db1 dJ/db1 ... dJ/dbm]/d[b1 b2 ... bm].
So anybody have some idea on how to derive the formulation
of dA/dB?
Thanks for your point on this problem.
Fred
...

**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...

**How to calculate the derivative of matrix w.r.t another matrix?**Dear All
I have a problem of calculating the derivative of dxm matrix A with respect
to another dxm matrix B,
where A= [a1 a2 ... am] and B =[b1 b2 ... bm] with
ai and bj are vectors.
Actually the matrix A itself is the first order derivative
of a scalar J with respect to B, i.e., A = dJ/dB,
where a1 = dJ/db1, a2 = dJ/db1, and so on.
Now dA/dB is the second order derivative
dA/dB = dJ^2/(dBdB')
= [dJ/db1 dJ/db1 ... dJ/dbm]/d[b1 b2 ... bm].
So anybody have some idea on how to derive the formulation
of dA/dB?
Thanks for your point on this problem.
Fred
...

**matrix calculation**hi,
i have two matrix A and B of the same size m*n*5. Now i need to
perform a calculation:
C(i,j,k) = A(i,j,k)/(A(i,j,:)*B(i,j,:))
so the matrix C will be of the same dimension m*n.
Instead of looping around for i = 1:m, for j = 1:n, for k = 1:5, is
there any other better way of doing this?
>
> C(i,j,k) = A(i,j,k)/(A(i,j,:)*B(i,j,:))
>
Did you mean A(i,j,:) * B(i,j,:) = sum_k A(i,j,k) * B(i,j,k) ?
In this case, you can do something like :
D = sum( A .* B , 3 ) ; % size(D) = m*n
C = A ./ D(:,:,ones(5,1)) ;
thanks,
by A(i,j,:) * B(i,j,:) i mean the dot product..
Erica
Gou...

**matrix calculations**can anyone give me any advice on how I should go about my problem
which is as follows:
I have two arrays - each holding the X an Y co-ordinate of the centre
of an object. I am trying to find the distance between each pair of
co-ordinates to other pairs of co-ordinates and then store the
distance in a matrix, for example, my two arrays are:
xCentres = [10.3529 20.6522 30.4717 32.5500 31.0000...]
yCentres = [33.7843 33.2319 235.6038 216.4375 138.6316...]
e.g. object 1 has X co-ordinate:10.3529, y coordinate:33.7843.
I want to calculate the distance between each object and store in a
matrix a...

**matrix for calculation**function [kr1, ka1, K1rot] = calculateKrKa(Fa, Z, Alpha, Di, Pi, Do, Po, N, d, dm)
Fan = Fa .* 9.80665 / 1000;
Alpharad = Alpha.* pi / 180;
w = Z .^ (2/3) .* Fan .^ (1/3);
z = Di * Pi ^ (1/3) + Do * Po ^ (1/3);
x = cos(Alpharad)^2;
t = sin(Alpharad)^2;
q = sin(Alpharad)^(1/3);
kr1 = (0.538*10) .* w .* x ./ z ./ q;
ka1 = (1.075*10) .* w .* t ./ z ./ q;
%K1rotational calculation
kz = ka1/(2*N);
kr = kr1/N;
r = dm/2;
K1rot = N*((r^2)*kz + (d^2)*kr);
Alpha is a 1x10 array. Fa is also a 1 x 10 array. how can i get this to work?
"relgn ng" <dream_w...

**Minor of a Matrix**I am a newbie to Matlab. I want to create a function that will take
a user inputted matrix and i, j values and ouput the minor of that
element.
On 2006-04-10 19:06 Taylor said the following:
> I am a newbie to Matlab. I want to create a function that will take
> a user inputted matrix and i, j values and ouput the minor of that
> element.
I=B4m not sure I follow you, but start by looking at
help function %and
help min
If that doesn=B4t help, please give a more detailed question.
HTH
PB
"Taylor" <tblake3@fau.edu> wrote in message
news:ef3060d.-1@webx.raydaftYaTP...

**Matrix calculations**Hi,
I would like to summarize a columns of a matrix by using:
x=0
for k=MyMatrix,x=x+k,end
MyMatrix is a onedimensional matrix. Unfortunately I don't get the sum
of the matrix, but x is a copy of MyMatrix. What am I doing wrong??
Another question is:
consider A=[1 2] and B = [5 6]
[3 4] [7 8]
I would like to multiply B with the bottom row of A to get:
C = [3*5 4*6] = [15 24]
[3*7 4*8] = [21 32]
How to do this as effcient as possible, does anybody know??
Kind regards, Darius Blaszijk
...

**How calculate the integral of the matrix**Hi all
I want calulate this:
Qc = [Tc*(integral((exp(A11*t))*B1*B1'*exp(A1')]^-1
A11 is matrix (3*3)
B1 is the vecteur (3)
please help me
...

**how to calculate matrix with out for loop**I = [ 1 1 1; 0 1 1; 0 0 0];
[m n] = size(I);
h = zeros(9, 1);
for i=1:m
for j=1:n
Z=I(i,j);
h(Z+1)=h(Z+1)+1;
end
end
above same code but should i use without for loop or use one for loop
please tell me suitable answer anybody
On Oct 13, 2:55=A0pm, "Jamal Mohamed" <in.ja...@yahoo.com> wrote:
> I =3D [ 1 1 1; 0 1 1; 0 0 0];
> [m n] =3D size(I);
> h =3D zeros(9, 1);
>
> for i=3D1:m
> =A0 =A0 for j=3D1:n
> =A0 =A0 =A0 =A0 Z=3DI(i,j);
> =A0 =A0 =A0 =A0 h(Z+1)=3Dh(Z+1)+1;
> =A0 =A0 end
> end
>
> above same code but s...

**calculating on matrix indices**Hello,
In my attempt to learn python, migrating from matlab, I have the following problem.
Here is what I want to do, (with the wrong syntax):
from numpy import *
t=arange(0,20,.1)
x=zeros(len(t),'f')
idx=(t>5)
tau=5
x[idx]=exp(-t[idx]/tau) # <---this line is wrong (gives a TypeError)
#------------------
what is the best way to replace the wrong line with something that works: replace all
of the values of x at the indices idx with exp(-t/tau) for values of t at indices idx?
I do this all the time in matlab scripts, but I don't know that the pythonic
preferred metho...

**calculating mean of matrixes**Hello everyone,
I have three matrixes 349x277, I would like to calculate the elementwise mean of those three matrixes.
So if I had:
A=
3 3 1
4 1 4
B =
1 2 4
2 3 1
I would want:
mean=
2 2.5 2.5
3 2 2.5
Sorry for asking something that basic, but I can figure out how to tell matlab to take the average elementwise...
Any help is greatly appreciated
Sandra
"Sandra" wrote in message <iv7k5m$2en$1@newscl01ah.mathworks.com>...
> Hello everyone,
>
> I have three matrixes 349x277, I would like to cal...

**calculating each element of matrix**Hi all
I am a highschool student studying matlab
What i want is to prgramming C matrix
if
matrix A (nx2), matrix B (nx2)
C(1,:)=A(1,:)-B(1,:)
C(2,:)=A(2,:)-B(1,:)
C(3,:)=A(3,:)-B(1,:)
C(4,:)=A(4,:)-B(1,:)
:
:
C(n,:)=A(n,:)-B(1,:)
C(n+1,:)=A(n,:)-B(2,:)
C(n+2,:)=A(n,:)-B(2,:)
C(n+3,:)=A(n,:)-B(2,:)
C(N+4,:)=A(n,:)-B(2,:)
:
:
C(n*n,:)=A(n,:)-B(n,:)
I ve tried like
I=1;
J=1;
K=1;
C(I,:) = A(J,:)-B(K,:);
for J = J+1
K = K+1
I = I+1
end
But failed, I hope some of you might help me
n = size(A,1);...

**Matrix calculation problem**Hello,
I have the following equation
[f]=[A]*[T]
SIZE(A)=[150 149]
SIZE(f)=[150 1]
SIZE(t)=[149 1]
A,f known and T unknown, and I want to determine T. Have you got any idea how to do it in a nice way?
inv(A) is not possible because A is not square matrix.
Thanks.
"John M" <ioannis.mitsos@gmail.com> wrote in message
news:ib1c8k$rp1$1@fred.mathworks.com...
> Hello,
>
> I have the following equation
>
> [f]=[A]*[T]
>
> SIZE(A)=[150 149]
> SIZE(f)=[150 1]
>
> SIZE(t)=[149 1]
>
>
>
> A,f known...