# All Questions

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 ...
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 ...
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, ...
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 ...
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 ...
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: ...
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 ...
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: ...
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 ...
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: ...
66 views

### Getting an approximate analytical form for eigenvalues of a matrix

I have a 20x20 matrix: ...
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 ...
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 ...
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 ...
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 ...
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, ...
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 ...
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 ...
90 views

...
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 ...
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 ...
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 ...
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, ...
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 ...
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? ...
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: ...
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 ...
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: ...
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 ...
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; ...
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 ...
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: ...
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 ...
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: ...
200 views

### LogPlot does not show all points

LogPlot ignores points which are going to "too high" values: ...
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. ...
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 ...
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 ...
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: ...
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 + ...
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 ...
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 ...
76 views

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: ...
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 ...
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++ ...
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 ...
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 ...