Thies Heidecke
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 Apr 12 comment How to numerically solve this non-standard Green's function using mathematica? You can use DiracDelta[] in the expression. This however, is only handled correctly by DSolve, which is limited to analytically solvable differential equations. Possibly related question with good hints by Leonid Shifrin how to tackle this kind of problem: mathematica.stackexchange.com/questions/61176/… Apr 12 awarded Scholar Apr 12 accepted Difference between two usages of TransformedDistribution Apr 8 comment Difference between two usages of TransformedDistribution oh, i see, thanks for the explanation! If you put this as an answer i would accept it! Thanks! Apr 8 awarded Student Apr 8 asked Difference between two usages of TransformedDistribution Feb 8 comment Identity Matrix in symbolic Tensor Product For me, (IdentityMatrix[3] + (TensorProduct[a2, b1]).(TensorProduct[a1, a2])) works fine (running Mathematica 10.3/Windows), giving: {{1 + a2 \[TensorProduct] b1 . a1 \[TensorProduct] a2, a2 \[TensorProduct] b1 . a1 \[TensorProduct] a2, a2 \[TensorProduct] b1 . a1 \[TensorProduct] a2}, {a2 \[TensorProduct] b1 . a1 \[TensorProduct] a2, 1 + a2 \[TensorProduct] b1 . a1 \[TensorProduct] a2, a2 \[TensorProduct] b1 . a1 \[TensorProduct] a2}, {a2 \[TensorProduct] b1 . a1 \[TensorProduct] a2, a2 \[TensorProduct] b1 . a1 \[TensorProduct] a2, 1 + a2 \[TensorProduct] b1 . a1 \[TensorProduct] a2}} Feb 4 comment Product of two Meijer's Function What are the domains of $\alpha$ and $\beta$? Are there any restrictions on their values? Feb 1 comment How to get the frequency information of an mp3 audio? If you know for sure that there is only a single (possibly amplitude and frequency modulated) sine oscillator active (e.g. $f(t)=a(t)sin(\omega(t)),\omega(t)=\omega_0 + \int_0^t 2\pi f(s) ds$), then you can see your waveform as the real part of a complex (as in complex numbers) oscillator. You can then use a Hilbert transform (see here) to get the corresponding imaginary part of that oscillator and use this to reconstruct $a(t)$ and $f(t)$ (which is just $\frac{d\omega(t)}{dt}$). Jan 17 awarded Yearling Nov 26 comment Eliminating instabilities in a transient finite element solution at a discontinuity near t = 0 @user21 Thanks for clarifying! Nov 26 comment Eliminating instabilities in a transient finite element solution at a discontinuity near t = 0 You can always try increasing the number of points in the spatial discretization with the "MinPoints" option or try a lower "DifferenceOrder" to decrease overshooting. Method Of Lines has some details. Nov 16 comment find the maximum number of not intersecting circles inside an ellipse You're welcome! If i find the time, i'll try to implement an example for the Metropolis approach. Nov 16 revised find the maximum number of not intersecting circles inside an ellipse added 71 characters in body Nov 16 answered find the maximum number of not intersecting circles inside an ellipse Nov 16 comment Detecting an ellipse in a glaucoma photo Is your question more about how to automatically find the ellipse pattern in an image? or about fitting an ellipse at a starting point in an image? or more about calculating the size of the ellipse? Please provide a minimal example. Nov 8 awarded Nice Answer Nov 2 revised solve ODE with divergencies fixed code typo Oct 31 awarded Good Answer May 16 awarded Enlightened