**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 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
...

**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
...

**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 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...

**Calculating determinant of a matrix**Hi guys,
I have to write my own function that can calculate the determinant of a matrix.
It is my first time that I want to write a function in Matlab, would you please help me in this matter?
Kind Regards,
Fariba
> Hi guys,
>
> I have to write my own function that can calculate
> the determinant of a matrix.
> It is my first time that I want to write a function
> in Matlab, would you please help me in this matter?
>
> Kind Regards,
> Fariba
Use the same strategy as already built-in in MATLAB
(LU-factorization of the matrix A):
http://www.m...

**How to calculate Hessian Matrix**Hi,
Does anyone know where there is any function/subroutine can compute
the Hessian Matrix of a multivariable function? Thanks a lot!
John
On 5 ao=FBt, 04:45, John <john131...@yahoo.com> wrote:
> Hi,
>
> Does anyone know where there is any function/subroutine can compute
> the Hessian Matrix of a multivariable function? Thanks a lot!
>
> John
First of all, your are not posting in the right group.
It is very easy to compute an Hessian matrix using numerical
derivatives. The only problem is the cost especially if the multi
variable function is itself a "vector...

**Re: matrix calculation?**Hi Feixia,
You don't need matrix calculation, you need PROC MEANS, which does the calculation for you based on records with data. Your A variable must be the CLASS or BY variable. You can save your aggregated data per person (A) with OUT= in a dataset for further use; define the statistics you want to have output. See your docs.
Regards - Jim.
--
.. . . . . . . . . . . . . . . .
Jim Groeneveld, MSc.
Biostatistician
Science Team
Vitatron B.V.
Meander 1051
6825 MJ Arnhem
Tel: +31/0 26 376 7365
Fax: +31/0 26 376 7305
Jim.Groeneveld@Vitatron.com
www.vitatron.com
My statisti...

**problem with calculation of a matrix**Dear SAS users,
I would appreciate any help with the following problem. I have a
vector of numbers as follows:
1
2
3
4
5
;
and would like to obtain a matrix where:
-on diagonal I have: ai^2 if i=j
-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
Can anyone help me with some code? I am new to IML and would
appreciate some guidance. Thank you!
Paul
On Jun 13, 12:17 pm, PBilin <pbi......

**symbolic matrix calculation**Hello,
I am trying to find the characteristic polynomial of a Jacobian matrix
J, where J is a Jacobian of a symbolic 10x20 matrix A(x1,...,x10).
J=jacobian(A,[x1 x2 x3 x4 x5 x6 x7 x8 x9 x10]);
pJ=poly(J);
The program is halted because it requires too much memory space. Do
you have a good idea to implement this with small memory size?
regards,
JS
...

**calculating an inverse matrix**So far I know the method of Gauss-Jordan(with pivot to reduce
instability), but are there other(better) methods to calculate an
inverse matrix?
Hi Michael,
e.g. look up "PseudoInverse". This methods uses singular value
decomposition and can even with badly conditioned matices.
hope this helps, Daniel
michael.goossens@gmail.com wrote:
> So far I know the method of Gauss-Jordan(with pivot to reduce
> instability), but are there other(better) methods to calculate an
> inverse matrix?
>
"michael.goossens@gmail.com" <...