7
votes
1answer
145 views

Why is RegionMeasure so slow when calculating intersection area of a 2D and a 3D object?

If you think this description is too long, you can read the problem directly I know normally when one wants to calculate an region, this guide is useful. However, when it comes to calculating an ...
3
votes
1answer
56 views

Remove cases where region specified incorrrectly

I am using MeshPrimitives to get a list of 3D components of a Mesh Region. Within that list, I normally get some incorrectly specified regions, such as ...
8
votes
2answers
173 views

Mesh Problems with MatrixPlot

I've come across some weird behavior in 10.1 when trying to use Mesh with MatrixPlot. In the example below, when specifying Mesh, I only get one line along the X axis at 100 instead of lines at {100, ...
0
votes
1answer
62 views

Plotting with 2 variables and given list of f(u,v) values [closed]

Lets say I have a function y with 2 variables u and v : $f(u,v)=y=u+4v$ I want to plot y in 2-D. My first axis is u and my second is v. How do I plot this, if I have a list of values for my y? I ...
1
vote
2answers
173 views

Combining data sets by adding y values [duplicate]

Suppose I have the following list of data {{1,2},{1,5},{6,1},{1,3},{2,1},{2,2},{2,3},{5,4},{5,2}} This is similar to my actual data in that each x value has ...
3
votes
2answers
106 views

Add Results of ParallelMap in Parallel

I'm new to coding in parallel, but I really could use it. I need a command to call a function on each element in a huge list, and then add them all up. Currently I use something like this: ...
2
votes
3answers
131 views

Positions of elements in a list [duplicate]

I have two lists: list = {1, 2, 3, 4, 5} slist = {3, 5} I want to find the positions of the elements in slist in list. I tried it like this and I dont understand ...
2
votes
0answers
164 views

Can't get map of Italy from Geographics [closed]

On Mathematica 10.1 Desktop version, I'm trying: GeoGraphics[Polygon[Entity["Country", "Italy"]]] but it doesn't get the Italy location and throws this error: ...
10
votes
1answer
303 views

Dirichlet coefficients as limits: wrong

Perhaps I should have included the word "bug" in my question. Here we go There is a bug in this Limit Limit[3^s (-1 - 2^-s + Zeta[s]), s -> ∞] (* 0 *) which ...
2
votes
3answers
289 views

Solve a transcendental equation in Mathemathica

I believe it is called a "transcendental equation", and I would like to find the best possible sollution. I tried to use Solve: ...
1
vote
0answers
66 views

Getting an approximate analytical form for eigenvalues of a matrix

I have a 20x20 matrix: ...
3
votes
1answer
193 views

Finding closest point to implicitly defined curve

I'm facing the following problem: Given an implicit curve given by $f(x,y)=0$ and an initial guess $(x_0,y_0)$ which is hopefully close to the curve, I want to find the point $(x,y)$ on the curve ...
1
vote
0answers
94 views

What is the font that is most similar to latex fonts? [duplicate]

I am producing mathematica graphs so I hope the axis font can be as similar to latex fonts as possible. This is because I need to put them in a latex document. $\LaTeX$ and Mathematica What is ...
0
votes
1answer
101 views

second order nonlinear ode

I need to solve the following equation for $u_n(t)$: $u''=\frac{u'^2}{2u}+\frac{3u^3}{2}+4tu^2+2\left(t^2+\frac{n}{2}+(2p+1)\frac{1+3(-1)^n}{4}\right)u-\frac{n+(2p+1)(1-(-1)^n)}{4u}$ where $p$ is a ...
7
votes
1answer
144 views

How to debug this failing pattern-matching expression?

NB: this question is primarily about troubleshooting and debugging, and only secondarily about pattern-matching. IOW, I'm far less interested in getting an explanation for the situation described ...
5
votes
1answer
128 views

RegionIntersection fails for some values with polygons

Bug introduced in 10.1 and fixed in 10.3.0 I want to find the intersection (region) of 2 polygons. I use RegionInstersection but it only works for some sizes, ...
3
votes
1answer
155 views

Adding FrameLabels but without showing a Frame using GraphicsRow

I'm trying to create a set of plots that share similar axes (axes in the general sense, I'm actually using Frame). I'd like to have the text describing the axes plotted to the left of the first plot ...
2
votes
1answer
167 views

Drawing lines automatically between two different plots

I try to create a special plot where several lines have to be generated automatically between two plots at very precise coordinate. My goal is to make something exactlly like But I want to do it for ...
2
votes
0answers
90 views
5
votes
0answers
94 views

Is there a problem with some of the curated Star Data?

I'm not really sure if I'm doing something wrong, or if there's a problem with some of the Mathematica curated data on stars. My problem is this: I'm trying to find the location (latitude and ...
2
votes
1answer
91 views

Nonlinear abscissa in TimelinePlot

I would like to produce a TimelinePlot in which the scale of the abscissa varies nonlinearly (compressing old dates and expanding recent dates). Others have ...
2
votes
2answers
97 views

Union sorting after ignoring some digits

I have a list with its bellow elements: {-0.7071067811865476, -0.7071067811865475, 0.7071067811865475, 0.7071067811865476} If I use ...
17
votes
2answers
799 views

Export Plot3D in Mathematica 10.1 is Rasterized by default

When I use Export to export Plot3D to PDF format, I get different behaviour in Mathematica 10.1 compared to 10.0. In particular, ...
0
votes
1answer
57 views

Mapping Linear Model Fit Over An Arbitrary Number of sets

I have multiple sets of data, and I want to apply Linear Model Fit sequentially to each set of data. For example, below tstlst contains 3 data sets. Right now I ...
5
votes
2answers
309 views

FEM giving “ … is not a polynomial error”

Executing the program below I get the ... is not a polynomial error message. I don't have an idea why I am getting this -- any suggestions? ...
3
votes
2answers
153 views

Image smoothing with own smoothing function

I have thousands images similar to the following one: This image was produced with the following color table: ...
2
votes
1answer
106 views

Using Epilog to increase text size [closed]

I have a plot with labels positioned using the epilog function for convenience. I would like to increase the size of axes labels within the epilog function but I haven't managed to figure out a way to ...
1
vote
0answers
50 views

Partial Derivative of f with respect to x1 [duplicate]

How can I calculate the partial derivative of a series like e.g. $$ a = \sum _{i=1}^n \left(2 x_i^2+z\right) $$ with respect to $x_{1}, x_{2},... x_{n}$ using Wolfram Mathematica? I tried it with: ...
0
votes
1answer
88 views

Complex contour plot of a function of three complex variables [closed]

eqn[x1_, y1_, x2_, y2_, a1_, a2_] := ((a1 + I a2) - (x2 + I y2))/(((x1 + I y1)(x2+ I y2)) - (a1 + I a2)) How can I plot the ...
4
votes
1answer
167 views

What is the difference between Update, Run Package, Save and Install for packages?

I am building a package, using Mathematica 10.0.2.0. I notice in the displayed window for the package there are buttons labeled Update and Run Package; on the File menu, there is an item for Save; ...
2
votes
0answers
85 views

MatrixRank of a large but sparse matrix

I want to find the rank of a very sparse, quite rectangular matrix mat, but I'm running out of RAM (I have 16 GB) if I try to use ...
6
votes
3answers
170 views

Easy way to bind rect to geometrical 2D line?

I got stuck with the following problem. For some calculation and visualization purposes I need to draw different shapes (like rectangle) with proper slope on custom line. The trivial example: ...
0
votes
0answers
40 views

3D interpolation [duplicate]

I have four column data with first 3 column denoting x,y,z and fourth column energy. x variable is actually angle. Now I want to interpolate over all three indepdent variable (x,y.z) with ...
9
votes
0answers
96 views

Strange result of DeleteCases in an association

The function DeleteCases can be used for associations, also with level specification. Here is an example where some values are associations: ...
6
votes
3answers
200 views

LogPlot does not show all points

LogPlot ignores points which are going to "too high" values: ...
7
votes
2answers
239 views

Connect to USB Serial Converter

(I'm using Windows 7 & Mathematica 10) I have a sensor with RS232 serial interface. The sensor came with a RS232-to-USB converter and corresponding driver & software for data transportation. ...
7
votes
3answers
493 views

How to put an imported image in a Disk?

The image below contains various ( lightblue filled ) circles ( made with the Disk function ), I want to fill them with an external image ( for example of a face ) such that each circle contains the ...
2
votes
2answers
383 views

How to do make Plot automatically figure out a domain interval?

When you tell Wolfram|Alpha to plot something, it automatically figures out a reasonable domain to plot it over. When I try something like Plot x^2 + y^2 = 1000 ...
3
votes
2answers
203 views

Manipulate a 2D point controlled simultaneously by Locator and its coordinates

I'm trying to have a point in the plane which can be manipulated both using Locator as well as inserting its $x$ and $y$ coordinates. My attempts at doing this are: ...
-1
votes
1answer
193 views

Solve a differential equation using the power series method

I used the power series method to solve the differential equation y’’+y=0 with y[0]=0 and y’[0]=1 using the following code. In this code “y” is considered as “y = Sum[c[i] x^i, {i, 0, n}] + O[x]^(n + ...
0
votes
1answer
118 views

How to enter piecewise functions into Mathematica [closed]

I'm trying to enter a piecewise function (named eq30) into Mathematica. However, it seems not to work. The expression I entered is ...
3
votes
2answers
139 views

How do I make a Graphics3D Object act as a Button?

The original idea is from: http://demonstrations.wolfram.com/ClickACountry/ What I'm trying to do is to create a series of Graphics3D objects and let them control the display of corresponding ...
7
votes
1answer
76 views

Is $ModuleNumber working properly on my machine?

In the documentation ref/$ModuleNumber, I read: Every Wolfram System session starts with $ModuleNumber set to 1. Yet, when I quit Mathematica 10.1 (OS X 10.10.4), restart it, open a new notebook ...
1
vote
3answers
393 views

Random non-overlapping disks in a square

I've found a nice code snippet by @belisarius from this question, that I'll reproduce here for reference: ...
2
votes
0answers
121 views

Performing a convolution for smoothing a function

I want to smooth a one-dimensional oscillating function by convolving it with another function that I'll call the screening function. This screening function should have a trapezoidal form and go to ...
0
votes
0answers
67 views

Linking to C++ files [duplicate]

I have written mathematica file that does manipulations on a certain set of points. I would like to access code that someone else has written for a least square fit in C++. How do I access this C++ ...
2
votes
1answer
633 views

Solving a transcendental equation

I want to solve the a transcendental equation, e.g. NSolve[-(1-x)*Log[1-x] - x*Log[x] == 0.5, x] Mathematica is not able to solve, wheres WolframAlpha -- is able ...
2
votes
1answer
117 views

How do I extract units from an expression

I need to take the units off of this expression: (5 Coulomb)/(6 Second) In order to do some unit simplification. Is there any way to do this? I have tried Case, but could not get it to work ...
4
votes
1answer
79 views

Set control A to a specific value if control B is ever changed?

I've had trouble with this and issues similar to this in the past, where I need to track when a controlled variable is changed. Basically I have two Sliders (call ...
2
votes
1answer
87 views

Converting a quantity to a decimal form [closed]

I have a function giving me this: (5 Coulomb)/(6 Second) as output. I want this in decimal form and would like to have the variables taken off the end for unit ...

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