3
votes
3answers
165 views

Inefficient NIntegrate and Which

In version 10 a simple numerical integraton of piecewise function is highly inefficient: ...
1
vote
2answers
216 views

Problems finding intersection points between line and generic function

I'm trying to find Intersection points between a line, which is given by 2 points, and a generic function (I want it to be able to handle polynomial functions, circles/ovals, lines and all ...
0
votes
0answers
34 views

How to change number form of Plot Legend in ListContourPlot? [on hold]

I am creating a ListContourPlot from some very large values. I would like these numbers to be written out in scientific notation (8x10^8, etc.) I've tried the following code: ...
1
vote
2answers
94 views

How to write a loop

I try to create a table which will describe traffic paths at a crossroads. Instead of using copy-paste repeatedly, I would like to write a loop. For example: ...
3
votes
0answers
49 views

How to produce timely spoken text?

On my system (Mac OSX 10.10.4) the following code produces only the first utterance. The second one is produce when the user interacts in some way with the front end (mouseover, mouseclick). How can I ...
18
votes
1answer
178 views

Systemic bugs in GraphPlot and related functions such as TreePlot and TreeForm

Bug introduced in 7.0.1 or earlier and persisting through 10.2.0 I believe I have come across a rather curious bug in TreeForm: ...
0
votes
0answers
8 views

Don't understand about how to solve the first equation with Gauss Elimination [migrated]

Please take a look at the picture. My quesion is: How to solve the first equation with Gauss Elimination that is displayed in the picture. I don't understand HOW.
4
votes
2answers
46 views

Inputting values into the variables without having to input the matrix all over again

I'm practicing using LU decomposition on Mathematica. I am able to find the L & U matrices, specifically the variables. However, i find it tedious having to input the newly found values and form ...
4
votes
3answers
280 views

Implementing Picard's Iteration for solving ODEs

Picard's Iteration is a way of solving the IVP $$y'(x)=f(x,y(x)), \quad y(x_0)=y_0 $$ It consists of defining the following sequence of functions recursively: $$y_0(x):=y_0 \\ ...
2
votes
1answer
121 views

Equation involving hypergeometric functions

I want to solve this equation but nor NSolve nor Solve are able to do this. ...
6
votes
2answers
249 views
6
votes
0answers
36 views

Override a PlotTheme element at the Options level?

Plot properties defined in a Theme override (supersede) properties defined on Options. This can be undesirable in a case such as: ...
0
votes
0answers
4 views

How to solve a equation task [migrated]

I have found a equation task that is: y=0,5x+2,5 y=3x-1 The answer and its process is: ...
1
vote
0answers
44 views

How to segment letters and text blobs?

This new article from Google research describes how their Translate app preprocesses an image on a phone before applying convnets: It needs to weed out background objects like trees or cars, and ...
7
votes
0answers
89 views

How to make a Nebulabrot?

A Nebulabrot is a generalization of the Buddhabrot, a fractal rendering technique related to the Mandelbrot set that sort of looks like a meditating buddha. The Buddhabrot rendering technique was ...
14
votes
1answer
265 views

What Method options does FindInstance accept?

While answering Trouble getting FindInstance to return multiple results for certain constraints it became clear that for this problem FindInstance would be better ...
0
votes
1answer
109 views

How may I avoid ParametricPlot3D clipping? [duplicate]

What I am doing: ParametricPlot3D[{Cos[z/2]^6 * Cos[t],Cos[z/2]^6 * Sin[t], z}, {t,-Pi, Pi},{z,-Pi,Pi}] What I get: What I want: what I get, but without the ...
3
votes
2answers
72 views

Find sub-sets of vanishing additions or subtractions from a list?

Let's say I have a list L containing n numerical numbers. Now I want to find all sub-sets of ...
0
votes
0answers
22 views

Vector field plot not appearing in VectorPlot3D

I am having trouble in plotting the vector fields - Bfield and Avector - with the VectorPlot3D function. Here is the code used to Compute Bfield and Avector: ...
0
votes
1answer
66 views

How to disqualify a rule [on hold]

Executing this line Assuming[x < 0, x -> 10] Expected output: False Say x -> 10 is a root of a polynomial ...
12
votes
1answer
206 views

How to monitor the progress of training a classifier?

I've had p = Predict[x -> y] running for hours and I have now idea if I should kill it or not. I'm looking for some rough bounds for an estimate of how long ...
1
vote
2answers
42 views

How to define a function `deriv[f[x]]` such that its output is an unevaluated expression `fx=D[f[x],x]`?

I want to define a function deriv[f_[x_]] such that when I run deriv[f[x]], the output is an unevaluated expression ...
1
vote
2answers
43 views

What can I use as an equivalent of python zip in mathematica inside of Sum[]? [on hold]

I want to take two lists of the same length: widths and weights, and sum a function (of 3 variables) over a single index using the elements from both lists that have that index. Then I want to plot ...
16
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 ...
1
vote
2answers
37 views

Error Resulting from Placing a Dynamic Variable inside of Table

I want to create a list of values, True or False, and to update those values with a ...
2
votes
0answers
61 views

What am I missing in this highly oscillatory integral?

I want to numerically integrate this equation (in python without calling Mathematica): $\int_0^\infty {\rm d}k f(k) J_v(r k) J_n(s k)$ where $f(k)$ is a non-smooth function, $J_v$ are the Bessel ...
0
votes
1answer
57 views

Count participation of variable list

I have the directed edges of a graph given by a list of variable (vertex) pairs. ...
3
votes
0answers
53 views

Where's the service status page for Programming Cloud?

I've searched wolframcloud.com and found none. It would be good to know, because I am getting a range of apparently random failures from "Tag List ... is Protected" to "possible crash" (!) to "Cloud ...
0
votes
0answers
30 views

Interpolating function for data with five independent variables [on hold]

I have to optimize the risk reward of a financial structured product depending on several variables: the tenor (between 12 and 36 months), the type (american, european), the Knock In (KI) ...
8
votes
0answers
193 views

FindRoot kills kernel

Bug introduced in 7.0 or earlier and fixed in 10.1.0. I'm having problems with FindRoot killing the kernel. In my real application, I want to ...
16
votes
0answers
2k views

How to visualize Riemann surfaces?

In WolframAlpha we can easily visualize Riemann surfaces of arbitrary functions, can we plot the Riemann surface of an arbitrary function using Mathematica and ...
4
votes
0answers
69 views

Extraneous reaped data with NDSolve and WhenEvent

Bug introduced in 9.0 or earlier and fixed in 10.1 In exploring What is the range of values $x$ for which $f(x)$ is higher than $k$ over a given domain?, I came across the following strange ...
8
votes
1answer
93 views

Iterator variable not blocked in ParametricPlot

Bug introduced in 10.0 and persisting through 10.2 or later It appears that perhaps the iterator variable r is not Block-ed ...
11
votes
1answer
167 views

Using Simplify on a consistent system returns False

Bug introduced in 8.0 and persisting through 10.2 or later It's late, but am I missing something here? Why should two independent equations, which together are consistent, ...
11
votes
0answers
203 views

Bug in plotting function using FindMinimum?

Bug introduced in 10.0 and persisting through 10.2 or later While working on an answer to RegionPlot from NDSolve, I came across this strange behavior of ...
4
votes
1answer
106 views

LogLogPlot plugs in zero

Bug introduced in 10.0 and fixed in 10.0.2 In testing the answers to Plot result of non analytical-integral in V10.0.1, I came across this behavior of ...
3
votes
0answers
33 views

Tracking features where ImageFeatureTrack finds none?

How is it possible to track common features in the following sequence of images (e.g. holes or corner points along the top margin), ? I have had no luck with ...
23
votes
1answer
2k views

Upgrade to Windows 10

Can users of Mathematica on Windows 7 or Windows 8/8.1 upgrade their computers to Windows 10 – a process that began today? Does Mathematica work? Are all the settings, licenses, access to files and ...
32
votes
2answers
762 views

String-manipulation bugs in v10.1

Fixed as of 2015-04-06 via paclet update. The new version 10.1 has introduced some strange (possibly buggy) behaviour compared to v10.0: ...
2
votes
0answers
31 views

Fishing for monomials in a nested or partially factored polynomial stream

I have a problem where I'd like to be able to take a multivariate polynomial whose variables are nonscalar and is not written explicitly as a sum of it's nonzero monomial terms and determine which ...
2
votes
0answers
283 views

Crank-Nicolson scheme for the Schrödinger equation

I am trying to solve the 1-D Schrödinger equation with the Crank-Nicholson method. I use the atomic units: time < 10^-14 => 413 a.u.t. length 30 * 10^-9 m => 567 Bohr radii ...
2
votes
1answer
45 views

How to extract part of association?

Considering an association: asc = <|"a"->1, "b"->2, "c"-><|"e"->3, "c"->4|>, "d"->5, "e"->6, "f"-><|"g"->7|>|> How ...
5
votes
3answers
151 views

List all “duplicate” elements in Tally

Tally[list,test] can use a custom function test to judge if elements are equal. But the output will only give the first element ...
5
votes
0answers
42 views

A book or tutorial/guide for “Systems Interfaces & Deployment”

I'm looking for a complete guide (call it a book, tutorial, guide or whatever) about some programming topics which are not enough covered by Mathematica Documentation Center, in my opinion. Topics ...
0
votes
1answer
58 views

Plot a circle and create a 3-D revolution plot out of it

If I have the equation (x-2)^2 + (y-2)^2 == 1 I can use a ContourPlot, however am having trouble changing the axes origin. I ...
1
vote
1answer
67 views

Pulling out a prefactor from a dot product

I have three complicated vectors u, v and w as well as three simple prefactors ...

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