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bio website quantum.at
location Vienna, Austria
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visits member for 2 years, 2 months
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PhD student in Theoretical Physics

Research interests include Quantum Optomechanics and Quantum Optics


Jul
29
revised Assigning row of values to a lower triangular matrix
added 220 characters in body
Jul
29
revised Assigning row of values to a lower triangular matrix
added 26 characters in body
Jul
29
comment Assigning row of values to a lower triangular matrix
I like yours the best btw, especially the NestList ones
Jul
29
comment Assigning row of values to a lower triangular matrix
@Mr.Wizard I thought about adding your suggestion but Artes has it in his answer, so I guess it's not necessary...
Jul
29
revised Assigning row of values to a lower triangular matrix
added 114 characters in body
Jul
29
comment Assigning row of values to a lower triangular matrix
@Mr.Wizard Now that I reread the question I think you are right
Jul
29
answered Assigning row of values to a lower triangular matrix
Jul
29
comment Why does Mathematica fail to series expand this simple expression?
@partial81 ad 1) Use Help>Give Feedback, ad 2) Often there will be one or two minor updates (eg. 8.0.1) which fix some bugs.
Jul
27
comment Generating a “best fit” curve to a set of noisy data corresponding to a moving object
Extending @ThiesHeidecke comment: The choice of the best algorithm depends on the model you use to describe the movement of whatever it is you're tracking. The Kalman filter is the optimal estimator (in a mean-square-error sense) for Gaussian (and therefore linear) systems, although they can be extended to (approximately) deal with nonlinear systems (eg. extended KF). I don't know much about particle filters but from what I understand they are not subject to these restrictions.
Jul
26
comment Is it possible to separately call the default value of a variable which isn't at the end of the sequence?
@Nasser Sure they could, but I don't think the solution would fit the OP's expectation.
Jul
26
comment Is it possible to separately call the default value of a variable which isn't at the end of the sequence?
@Nasser Well isn't that what options are?
Jul
25
comment Simple rule appears not to work
Yes, because rules apply to the FullForm of an expression. If the FullForm does not match then nothing will be replaced. The pattern you use for the replacement is pretty complicated so it is not very surprising that it only matches in a few special cases. Rewrite your rule such that the left hand side is simpler and try again.
Jul
23
comment Isolate a specific contour without Contour Shading
In that case I think one could use p/.Tooltip[_, Except[label]] :> Sequence[] to delete the unwanted lines...
Jul
23
comment Isolate a specific contour without Contour Shading
There is just one thing to do... select the lines corresponding to one value only. But that should be possible by the tooltips. Or maybe even a better way?
Jul
23
comment Solve equation containing conditions (If expressions)
Why don't you just integrate the PiecewiseExpand//Simplify solution in your answer? It was your idea anyway. And I think you can get rid of the obsolete part of the answer, nobody will mind.
Jul
23
comment Solve equation containing conditions (If expressions)
Yes, in version 9 AAA // PiecewiseExpand // Simplify yields dc == -0.00005 || dc >= 2.49955 and AAA // Rationalize // PiecewiseExpand // Simplify gives 1 + 20000 dc == 0 || 20000 dc >= 49991.
Jul
23
comment Solve equation containing conditions (If expressions)
Nice, it's quite amazing that this works. Just an aside: You don't even need the Reduce, a simple AAA // PiecewiseExpand // Simplify does the job (even without the warning).
Jul
21
answered Automatically generated summation region
Jul
21
comment Automatically generated summation region
You could use something like Sum[1,Evaluate[Sequence@@{{i,1,2},{j,1,2}}]]
Jul
21
comment Matrices and polynomials: MMA 8 vs. 9?
@nardol5 I just want to point out that MatrixFunction shows the same behaviour as MatrixPower if asked to compute T^0 (where T is not positive definite), which caused your code to fail in the first place! Try MatrixFunction[#^0 &,T].