18
votes
5answers
1k views

Insphere for Irregular Tetrahedron

I am looking for existing Mathematica code to compute the unique sphere inscribed inside an irregular tetrahedron. I can write it myself, but I would love to find that someone already performed this ...
17
votes
0answers
301 views

RegionPlot returning a number

Bug introduced in 10.0 and persisting through 10.4 or later I had updated my mathematica to version 10 few days ago. And I had been shocked by the following fact: ...
16
votes
2answers
271 views

A bug in Commonest in version 10

Bug introduced in 10.0.0 and fixed in 10.0.2 m_goldberg demonstrated that in Mathematica 10 Commonest does not behave as the documentation indicates that it will....
15
votes
3answers
324 views

Why does Mathematica simplify $x/x\to1$?

If I enter x/x, I get 1. Such behavior leads to this: Simplify[D[Sqrt[x^2], x, x]] 0 ...
15
votes
1answer
448 views

Why do Arrowheads interfere with ImagePadding?

Bug still present in version 10 under Windows. In a recent posting, Belisarius solved a problem related to the display of arrows on the x and y axes by setting ...
15
votes
3answers
947 views

How to remove accents from text?

I would like to know how I can remove accents from a string. For example, how can I transform "string test áéíóú" into ...
15
votes
1answer
460 views

Strange behaviour of Reduce for Mod[x,1]

For every integer $x$ the equation Mod[x, 1] == 0 holds. While Simplify[Mod[x, 1] == 0, Element[x,Integers]] gives ...
14
votes
2answers
377 views

FindInstance returns Indeterminate in version 9, but not in 8

Bug introduced in 9.0 and fixed in 10.0.0 Here is a trivial system of equations in three unknowns for which FindInstance obtains a solution: ...
14
votes
3answers
776 views

How do I “start a reference system”?

When I attempt to insert a citation or specify a database to use as a bibliography, I get a message that I need to "start" the "reference system" "manually": I have no idea what a references system ...
14
votes
3answers
650 views

How would I return a random Mathematica command?

I'm doing some metaprogramming. How would I make a Mathematica function that returns a random Mathematica command? Is there a list of command names that I could use ...
14
votes
2answers
463 views

Why do NumberForm and Round apparently use different tie-breaking methods?

When rounding numbers (for example, rounding a real number to the nearest integer), the "round to nearest" rule is usually used. For example, 1.4 is rounded down to 1 and 1.6 is rounded up to 2. ...
13
votes
2answers
575 views

How to embed an image into a string?

Note: The bug described in the post is in Mathematica 9, and has been fixed in 10.0. The documentation for String contains the following statements: Strings ...
13
votes
1answer
828 views

Problems with “Test Connectivity” and the Pacletserver

I know there has been a similar questions to this already but the solution did not work for me so here again: I have internet connection and I can execute such commands like: ...
13
votes
5answers
826 views

Does $x>0$ imply that $x\in\mathbb{R}$?

Let’s assume I input Assuming[x > 0, expression] Is it assumed by Mathematica that $x$ is a real number? Or that the real part of $x$ is positive? Something ...
13
votes
4answers
2k views

How do I find the degree of a multivariable polynomial automatically?

I have a very simple question which appears not to have already been answered on this forum. Is there built-in functionality that returns the degree of a multivariable polynomial? For example if the ...
13
votes
1answer
541 views

Evaluation indicator for a notebook

I have a GUI with a number of TabView and other Manipulate controls. Sometimes clicking from one tab view to the other can take ...
13
votes
1answer
336 views

ToNumberField won't recognize Root as an explicit algebraic number

Bug fixed in 10.0.0 In Mathematica 9.0.1, it appears that ToNumberField will not always recognize a Root object as an ...
12
votes
5answers
343 views

Make a ragged list rectangular by trimming instead of padding

I have a ragged list ragged = {{a,b,c,d,e},{x,y,z}} that I would like to trim (on the right) to be rectangular. The desired result is ...
12
votes
2answers
284 views

Evaluate selection in new window or new notebook?

Sometimes when you have long code you need to check some part of this code. the way I am using currently is to selected the part that I want and then copy it to new notebook and then evaluate it ...
12
votes
2answers
1k views

Why is ListDensityPlot unable to plot datasets with extreme ranges

Consider the following dataset: data = Flatten[ Table[{x 10^-9, y 10^-9, x^2 + y^2},{x, -100, 100, 10}, {y, -100,100, 10}] , 1]; If I try to ...
12
votes
0answers
207 views

Possible bug with FourierTransform linearity

Each component is easily transformed but the sum is not: FourierTransform[f''[x], x, k] FourierTransform[f'[x], x, k] ...
12
votes
2answers
831 views

Why can't I change the value of MaxRecursion in NIntegrate when integrating BesselJ?

Bug introduced in 8.0.4 or earlier and persists through 10.4. I am trying to evaluate this integral numerically $$ \int_0^{\infty } J_0(q R) \tanh(q) \, \mathrm{d}q $$ for large values of $R$. ...
12
votes
1answer
138 views

Strange result of Reduce and ForAll

In the question Can Mathematica tell me if a polynomial has all real roots?, quite a few of interesting answers were given. I wanted to add another one, using quantors, and observed some strange ...
11
votes
2answers
325 views

Return partial result when MemoryConstrained aborts NDSolve

I use NDSolve to solve a large set (~400) of coupled ODEs. Sometimes, the memory (~4GB) gets filled up, and my computer becomes impossible to work with, because it ...
11
votes
2answers
565 views

How can I highlight a moving bar in an animation of a bar chart?

I wrote the following code, but I don't know how to highlight the moving bar. ...
11
votes
2answers
394 views

Memory leak in FE?

A very abridged example of what was originally a major leak ...
11
votes
3answers
524 views

How to debug the C code for LibraryLink?

Recently, I use the C to rewrite a Mathematica function NonzeroBasis[], please see here for fully descriptions. Here, ...
11
votes
6answers
2k views

Conditional options in Plot

I was hoping to incorporate an If function into a Plot option, as in ...
11
votes
2answers
459 views

How to deduce a generator formula for a polynomial sequence?

Consider a polynomial sequence $\{p_n\}$ generated by some (simple) rule: $$ \begin{array}{l} p_1(x)=x \\ p_2(x)=2 x-x^2 \\ p_3(x)= x^3-3 x^2+3 x \\ p_4(x)=-x^4+4 x^3-6 x^2+4 x \\ p_5(x)= x^5-5 x^4+...
11
votes
1answer
451 views

Predictive interface eats my Esc key

After updating to version 9, I found the predict interface very helpful except there is a small problem always annoying me: Consider this: I have a list ...
11
votes
2answers
2k views

Estimating the full width half maximum of a peak

I have a dataset of which I'm attempting to determine the full width at half maximum. A picture of the data is given below, and the dataset itself can be found here (pastebin). Now, this set has a ...
11
votes
2answers
1k views

Find Determinant/or Row Reduce parameter dependent matrix

I'm trying to find the determinant of a band diagonal matrix that has a parameter, $\kappa$, in some of the entries. Some entries are just numerical ones, others ($\kappa$ X number), while others are ...
10
votes
4answers
4k views

Plot columns of table if some condition is fulfilled

I have a table with data, for example MT = {{1, 80.3, 1, 4, 68}, {2, 80.5, 1, 5.5, 102}, {3, 80.0, 0, 4.2, 78}, {4, 80.4, 0, 3, 17}, {5, 80.2, 1, 5, 180}}; ...
10
votes
1answer
502 views

Modelling the effect of a structure on a “tsunami” (hyperbolic wave equation)

So, the hyperbolic wave equation can be quite easily solved in Mathematica like this: ...
10
votes
2answers
6k views

How do you put conditions on indices in a sum?

I'm relatively inexperienced with mathematica, so I apologize if this is a trivial question. I want to take a double sum over a function $f(i,j)$ of two indices, of the form $$ \sum_{i = -\infty}^\...
10
votes
1answer
108 views

Evaluation leak from Dynamic in Button's action

a = 1; Button["Print", a++] Button["Print", Dynamic[a++]] Button["Print", Dynamic[a++];] Button["Print", {Dynamic[a++]}] Dynamic @ a The second ...
10
votes
2answers
3k views

problem with coloring spherical harmonics

I want to color a spherical harmonics. So I write as follows. ...
10
votes
4answers
461 views

Finding a point from a set of contours such that it is nearest to a given point

I have several contour lines and one point. How can I find a point in one of those contour lines which is nearest to the given point? ...
10
votes
1answer
374 views

How can I change the style of every newly opened notebook?

I'd like to make Mathematica open a new notebook using the Natural Color template (under the Creative category) by default. Is that possible? If so, how?
10
votes
6answers
679 views

Flatten nested lists

I have a list as follows lis= {a, {{{b}, {c,d,e}}, {{f}, {g,h,i}}}} which I would like to flatten to ...
10
votes
1answer
5k views

Complex number operations: telling Mathematica variables are real

I want to do Conjugate[a + b*I], but when I do that, the solution is Conjugate[a] - I*Conjugate[b]; when for me, a and b are ...
10
votes
2answers
535 views

Why does ListPlot ignore some global options?

Bug introduced in 7.0.1 or earlier and fixed in 8.0.1' Why does the following plot no use the global PlotMarkers option? ...
10
votes
1answer
265 views

How to pass composite function list to SortBy?

In order to sort alphanumeric-as-string data of the form {"T3", "T14", "T1", "E2"}, so that "T14" comes after ...
9
votes
1answer
287 views

How do I determine astronomical transit times?

Mathematica, through the "legacy" Scientific Astronomer package, used to have the ability to easily determine accurate transit times of astronomical objects simply, with ...
9
votes
1answer
144 views

Is it possible to use the global definition of a symbol as part of its new local definition set in a Block?

Consider the following expression: Block[{Print = CopyToClipboard}, doSomething[]] Now all calls to Print from ...
9
votes
1answer
357 views

Front end crash on Export in 10.2 on OS X

Bug introduced in 10.2.0 and fixed in 10.3.0 Appears to be specific to OS X Mathematica 10.2 is reliably crashing for me when trying to export a pdf that has text with ligatures. For example: <...
9
votes
2answers
383 views

Define Log so that negative reals evaluate on lower edge of branch

I need to get Mathematica to evaluate the logarithm of a negative real number using the lower branch instead of the upper branch, so that while ...
9
votes
2answers
203 views

Substituting confidential tagged cells by a “content removed” cell

When producing a notebook with both code and text, I often end up with pieces of code, or even entire chapters, that I don't want to be shown on the final output. I generally hide or close them by ...
9
votes
3answers
2k views

Why don't * and ^ work as I expected on matrices?

For example, this input... {{1, 2}, {3, 4}}*{{1, 2}, {3, 4}} produces this output... {{1, 4}, {9, 16}} and this input... <...

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