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| Dear Wolfram Community: I am facing the problem of computing the gradient and divergence of a general tensor field. In particular, expressions like the following ones (in Mathematica symbolic notation). Grad[TensorProduct[A[t,X],... |
| Dear people and Wolfram Team: I was searching for geostatistical tools on the Resources page, and unfortunately I cannot find a basic function called the Variogram. What I found was a related (but a bit more complicated) function called... |
| Dear Gianluca Gorni: Thank you for your answer. I was thinking the same thing (about the meaninglessness of the divergence of a scalar), but it should be a solution, as thermal stresses exist in the real-world (they can even break railways and... |
| Dear Wolfram Moderation Team: Good morning, I am very thankfully surprised to you for selecting my post for the "Staff Picks" column! I took me a lot of time to do this, and after many trial-and-error attemps, I arrived at the form posted... |
| Dear professor Gianluca Gorni: Thank you very much for your help, now my problem is almost solved! I slightly modified the code received to allow for the following options: 1) non-numeric scalar symbols like "s0" or "s1[t,x]": ... |
| Done, thank you for the clue. |
| Here are the specifics: 1) Yes, all the X[i] should follow the same distribution, as the problem is related to the equiprobable sampling of a (very) big population of solid particles. 2) The list of operations I would wish to do is the... |
| Effectively the binomial theorem will hold IFF (big IFF) I succeed in putting the expression in a form compatible with it. The problems are: 1) The authors make a change of variable from **N** to **s = 1/n N**, where "1/n" is the same... |
| Dear users Tim Laska and Kuba Podkalicki: Thank you for your answers. Now, a few comments: 1) Tim Laska suggestion works very fine for rescaling transformations, but I'm not sure if it is enough for "mixed variables" transformations like: ... |
| The meaning of terms in the code (I have put a "->" in the legend where I have subtitututed a greek or script letter with a latin one) is this: 1. epsilon -> "e" (void fraction, unitless) 2. Kappa -> "Kd" (mass transfer coefficient, assumed... |