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location Zurich, Switzerland
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visits member for 2 years, 6 months
seen May 19 at 12:01

Aug
20
comment Sierpinski carpet with GraphData
thank you all very much!!!
Aug
19
asked Sierpinski carpet with GraphData
Aug
19
comment Generating a Sierpinski carpet
Now, the carpet is drawn...and it would be also good for us (mathematicians, or physicists) to obtain the corresponding adj.matrix. However, this can be possible if one makes the program think that the drawn object is a graph. Is there any intelligent way to do this? Sorry, if I am posting too stupid comment...Thank you very much in advance!
Dec
3
comment Plotting Error Bars on a Log Scale
this doesn't work either...does one have to install anything in addition? I get this message: Needs::nocont: Context ErrorBarLogPlots` was not created when Needs was evaluated. >>
Nov
30
awarded  Commentator
Nov
30
comment Plotting Error Bars on a Log Scale
Strange...Once I write: Needs["ErrorBarLogPlots.m´"], I get the following error: Needs::cxt: Invalid context specified at position 1 in Needs[ErrorBarLogPlots.m\.b4]. A context must consist of valid symbol names separated by and ending with `. >> ... Am I doing something wrong?
Oct
9
comment Make a density list plot/histogram from large, pre-binned data set?
Do you really need a density plot? Cannot you just use a ListContourPlot[]? IMHO, this looks much clearer and you can really see the pattern. What is more, you can also output a color-bar and use many more other features...
Oct
5
comment How to Delete Elements from List1 appearing in List2?
Thanks a lot, this works for any nested list! :) Great solution!
Oct
4
comment Counting negative values in list
Thanks! I was trying out something similar by putting imaginary parts into a separate list and then checking the length of it...
Sep
19
comment Counting negative values in list
Looks like this is a very nice approach. However, this doesn't work if one wants to count complex numbers in a list. I also tried the straight away form (where ev is the list of numbers): count[]; For[u = 1, u <= 6, u++, If[Abs[Im[ev[[u]]] > 10^-10], count++]; ]; But no results...Maybe somebody has already done something like that?
Aug
9
comment Orthonormalization of non-hermitian matrix eigenvectors
@F'x there can be a perturbed Hamiltonian which is not anymore Hermitian.
Aug
9
comment Orthonormalization of non-hermitian matrix eigenvectors
hm...I am currently working with 49*49 non-Hermitian matrix, and I desperately try to orthogonalize the left and right eigenstates with the given above advices. I often get computation errors and have no idea how to handle it. I have also tried the Lapack routine (in Python), but it has not output me all the imagionary parts of the eigenvectors. And I cannot check this analytically. Maybe, somebody had the same problem and can give me a nice suggestion? Look forward...
Jun
5
awarded  Nice Question
Jun
5
comment How do I keep the right ordering of eigenvalues using Eigensystem?
I always use two different commands Eigenvalues[Matrix] and Eigenvectors[Matrix], so that Eigenvalues[Matrix][[i]] corresponds to Eigenvectors[Matrix][[i]]. It is a bit easier for me to work with two different lists.
Jun
5
awarded  Supporter
Jun
4
awarded  Student
Jun
4
awarded  Teacher
Jun
4
answered When to use built-in Graph/GraphPlot vs. Combinatorica
Jun
4
comment Using Gather to rearrange my data
thank you very much for helping me! I used the approach of the first and the second suggestions, since it is mostly related to my research (graph theory), but I am sure that Gather can be a very good alternative.
May
24
asked Using Gather to rearrange my data