Hello,
I have a three dimensional FDTD code. The problem I have for simulation is one dimensional. How can I use this 3D FDTD code for the 1D problem. The 1D problem is like this: in one-dimension half of the problem space is filled with a dielectric medium and the other half is free-space. A...
Hello,
I have written 3D FDTD code with Mur ABC which gives correct results for time domain data.
Now I want to compute the resonance frequency of a rectangular cavity using this 3D FDTD code.
I donot know how I will do that.
Would someone please advise me the steps I need to follow now to...
Thank you so much for all the answers and the questions.
All these gave me the answer and the explanation that I was looking for.
Thanks a lot to everyone.
Hello,
In Fortran 90, will the performance (in terms of computational efficiency) of the following two be the same. If not, which one will be faster. Please advise with the reasoning:
(i)
do i = imin,imax
do j = jmin,jmax
do k = kmin,kmax
Several statements (rigorous...
Hello,
I have about 8000 files in a directory all having names like
file000001.txt
file000002.txt
file000003.txt
file000004.txt
----------
----------
file007999.txt
file008000.txt
Now I need to do 2 things:
1. I found out that I donot actually need the data from the files whose...
Hi,
I need to modify a shell script and add the following into it:
location: 200 200 1
location: 200 200 2
location: 200 200 3
---------
---------
---------
location: 200 200 449
location: 200 200 500
I thought using some awk command one could produce the series...
In mathematica FullSimplify[expression] is valid but is FullSimplify[expression=0] a valid expression or will it work as we expect (like what you explained). I tried but it didnot give any improvement... it simply showed the expression on left and zero on the right of the equal. Is there any...
If I want to simplify an extremely large algebraic expression which equals zero to a simple neat equation -- how do I do that in Mathematica (or symbolic package of Matlab). Giving you an example of the equation below:
(c1 (-1 + E^(I dx kx)) (-1 + v4))...
Hello,
My work is on numerical techniques which require to solve sparse matrices etc. All my work is in fortran and I have almost no skill in Matlab.But I have just realized that Matlab can do some computations quite easily with its built-in functions and I want to take advantage of this. I...
Hi DaleSpam,
Thanks a lot for replying.
G is symbolic, algebraic and complex. It was obtained from some symbolic computation in Mathematica (at one stage to get G it involves matrix inversion ). Each column of 18x18 matrix G has roughly 9 zeroes, 1 one and rest of the elements (around 8 / 9 on...
Hi,
I need to get a simplified equation by setting the determinant of the following expression to zero:
exp(j.omega.dt). [I] - [G]
Here, I is an 18x18 identity matrix and G is an 18x18 matrix that I got by doing some symbolic computation in Mathematica (in fact G is huge).
Can anyone...
Hi,
I have a 24000x24000 sparse matrix. I want to extract 4 blocks out of it;
(0,0) to (6000,6000)
(6001,6001) to (12000,12000)
(12001,12001) to (18000,18000)
(18001,18001) to (24000,24000)
By use of those my aim is to make a block diagonal matrix using matlab command 'blkdiag' .
Can...
That was extremely helpful. Thank you.
As my file has 24000 data I could never see that '1.0 e -008 *' part on the top.
I made my file shorter and found it there.
Now after using 'format long eng' command before everything I got the data in Matlab that looks like in the file. Thank you so...
Hi,
Thank you. Using %e I did not get any different outcome.
Suggested by someone I have used 'format long' command before those commands mentioned in my original post. This gave following improvement but still couldnot read data perfectly.
Some of the data from my data file are like...
Hi,
I have a formatted data file (obtained from fortran) which has 1 column and 24000 rows. The values are like
-0.8736252526127E-9
-0.1928287267367E-11
0.28373737626278E-12
etc etc.
I have tried to read these data in matlab using the following command :
fid=fopen('filename')...
Hello.
Can anyone help me in producing a Matlab code that will read a sparse matrix and then calculate the eigenvalues of it, show the sparsity pattern of it etc. I have the the sparse matrix data in compressed sparse row (CSR), compressed sparse column (CSC) formats and also in Co-ordinate...