# All Questions

0answers
82 views

### Is there a notebook to create entries for OEIS?

Is there a notebook to create entries for OEIS? I seem to recall something like this a few years ago, but I haven't been able to find one. It might be from MathWorld. Any suggestions? Edit If I had ...
1answer
82 views

### Hiding a Manipulate slider

I want to generate a different random initial condition for rule 110 using a Button for Manipulate, not a slider. How can I make the slider invisible here? I tried specifying ...
2answers
116 views

### How to efficiently get a list like this?

I want a function myfun that generates list like this ...
2answers
410 views

### Maximize[Cos[x - 1], x] is not evaluated

No explanation needed: Maximize[Cos[x + 1], x] Maximize[Cos[x - 1], x] producing ...
1answer
75 views

### Possible to dynamically redraw single plot of multiple shown together?

I am attempting to create a tool to visualize gradient, eigenvector, and eigenvalue information for a 2D surface. I want to show a contour plot of an inputted function and overlay the gradient and ...
2answers
228 views

### Polynomial expansion of operator

I am new to Mathematica, I am trying to generate the polynomial function of a operator. So for example, the operator $L$ is $\frac{\partial f}{\partial x}+\frac{\partial f}{\partial y}$, and I want ...
2answers
81 views

### CurrentImage returns almost fully black image

On Mathematica 9.0.1.0, Windows 7 SP1 Calling CurrentImage[] returns a black image, with a few non-black pixels near the top of the image, which may be some kind ...
2answers
90 views

### Strange behavior with Show command

I enter this: ...
1answer
122 views

### Is the divergence between Round and setting an explicit precision intentional or a bug?

Introductory remark: I take it (from Mathematica's online documentation), that Precision is effectively the number of significant digits, as seen by the system. ...
1answer
63 views

### LineScaledCoordinate problem for exact coordinates

Edit: Confirmed bug. CASE:2326540. Still the case in V 10.3. Solution: Wait and use N meanwhile. I've faced this problem ...
2answers
538 views

### Using map projections with astronomical data

I noticed that all important "Geoprojections" are available in projections for a spherical reference models: GeoProjectionData function; 1 - I am trying using the sinusoidal projection for ...
1answer
149 views

### ControlType -> None Vs. Module inside Manipulate (i.e. making everything local)

I'm building a program on another one made available in the Wolfram Demonstration Project. I've noticed that in the original code (working flawlessly) many variables were made local inside the ...
5answers
789 views

### Animate point going around a triangle

How can I animate a point moving on a triangle's sides? I can generate a triangle and point, but I have no idea how to define point movement. I'm guessing that I have to use $\sin$ and $\cos$ in ...
1answer
59 views

### How do I plot 3 (x,y,value) on a Histogram3D[] function?

I have been trying to plot data using the Histogram3D function but I've had no luck, in excel I have x, y and a value I want to plot for each pair, do I have to save this as a data file first? I have ...
0answers
131 views

### Proving large inequality in 6 variables

I have arrived at a very large inequality in 6 variables that I would like to prove is true. The command I have tried is the following: ...
1answer
103 views

### Preventing complex term in a differential equation solution

I am solving the initial value problem: $$y'=\frac{t+1}{t(t+4)},\quad y(-1)=0$$ I believe the correct answer is $$y=\frac14\left[\ln(-t)+3\ln(4+t)-3\ln 3\right]$$ with an interval of existence ...
2answers
200 views

### Import table from txt file with specific rows

I have a .txt file written as 1 2 3 4 5 6 7 8 9 10 11 12 I would like to import it as three matrices according to the rows. I used b = Import["d:\am.txt", {"Table", Range[1, 2]}] Seems it ...
2answers
168 views

### How can I get all solutions of a system of equations with Reduce?

The post What is the difference between Reduce and Solve? discusses the difference between Reduce and Solve. Now, with the ...
2answers
260 views

### Unable to fit function convolved with NIntegrate with FindFit even with NumericQ

I am attempting to fit to the convolution of a simple function with a Gaussian. (I realize this could be done with Convolve also, but I thought I could make it go faster this way). I am able to ...
2answers
185 views

### Probability of multivariate normal being positive on each coordinate

How can I find the probability that each coordinate of a specified multivariate normal distribution is positive? I tried the following, which I believed should work ...
1answer
359 views

### Boundary sphere partial differential equation

I am trying to solve partial differential equation in spherical coordinates $(\theta,\phi)$,but I don't know how to properly include boundary conditions of $\theta$. For $\phi$ it is periodic, but ...
1answer
264 views

### Is there any strategy to have a compiled version of FindFit or NonlinearModelFit?

Disclaimer: This is not a precise question with a definite answer. I know that neither FindFit nor NonlinearModelFit is in the ...
1answer
39 views

### Graphics3D loses interactivity in Dialog window

Is there a way to keep Graphics3D objects manipulable when they are embedded in a Dialog window (CreateDialog,...
1answer
236 views

### Fick's Law over Implicit Regions

I'm trying to solve 2D Fick's law of diffusion from the boundaries of a triangle (future shapes will include more complex implicit regions). I'm able to model diffusion without time in complex ...
1answer
251 views

### $3\times 3 = 6 + \bar{3}$ in Mathematica?

Can Mathematica handle this type of algebra, which is used very frequently in e.g. particle/nuclear physics? That is, I want to decompose a product of representations (in $SU(N)$ say) into irreducible ...
6answers
405 views

### For a given expression: if it appears, remove it, but if it is absent, add it

While reformatting Szabolcs's code from (42660) I noticed this interesting operation: ...
0answers
75 views

### Good sources of programming exercises for learning Mathematica programming? [duplicate]

I'm learning Mathematica programming. I wonder if there are any good sources of programming exercises particularly suitable for practicing Mathematica programming.
1answer
74 views

### What is the command for the shortcut _? [duplicate]

I was trying to look up what _? does but I couldn't find anything in the documentation and it's hard to look up symbolic strings because most search engines use these symbols internally.
1answer
114 views

### Using colorData and BarLegend in ListPlot

I read lot of questions about this issue, mainly: the stack code So,I tried create a list plot with bar legend , using the following code: ...
1answer
53 views

### Why returning False? [closed]

Can anyone explain the false? I'm trying to grab co-efficient in front of X^2 I think. I say I think as I'm following my tutors example using his screenshot the only difference between his question ...
1answer
182 views

### linear combination of successive elements in a list

Say I have a list $E$ and want to build a list $F$ with the entries $F_j=E_j-2E_{j-1}+E_{j-2}$. I know that this happens to be achievable by iterating the function ...
1answer
177 views

### Image3D with values outside of the range [0,1]

I am writing some functions in Mathematica for representing MRI anatomical image volumes. The natural way to represent such a volume seems to be as an Image3D form. However, I've noticed an ...
0answers
61 views

### SumConvergence fails in version 10

SumConvergence[(-1)^(n + 1) ((Cos[n^2] + Sin[n + 2])/7^n), n] Mathematica fails to provide a result (true/false) but wolfram alpha works. What should I do ? It ...
0answers
160 views

### Rendering a 3D volume with Image3D

I have 2D JPEG images, of 1024 x 1024 pixels, corresponding to a 500 x 500 square micron section. These images are taken from slices of tissue, each slice seperated by 10 microns. I've been trying to ...
2answers
159 views

### Showing an output without square brackets

Suppose that an output is which could be obtained from, for example, D[f[x, y, z], x] / D[h[x, y, z], x] I'm looking for a way to show it without the square ...
3answers
143 views

### Get the complement date range

Suppose that I have a date range list drlist = {{"2015-01-01", "2015-01-05"}, {"2015-01-07", "2015-01-07"}, {"2015-01-12", "2015-01-23"}} ...
1answer
212 views

### Definitions are not distributed to parallel kernels

Bug introduced in 10.0 and fixed in 10.0.2. I have a small package with utilities, which looks like that: ...
2answers
144 views

### Compress uses too much memory and sometimes crashes the Kernel

Using Compress is a good idea to save memory when working with large expressions. The problem is that Compressing large ...
1answer
146 views

### Replacement of terms/Pattern matching involving products of derivatives of a function

In delving into Ramanujan summation, I'm trying to get a hold of the relations of the form \sum_{n=0}^\infty f(n)=\dfrac{h\frac{d}{dx}}{{\mathrm{e}^{h\frac{d}{dx}}}-1}\int_{0}^\infty ...
1answer
85 views

### Cannot shade 3D vector in different color

I need to color each vector into different colors... but this formula just doesn't work: ...
0answers
52 views

### Where can I find documentation for the File->New->Package window?

I'm using 10.0.0 on OS X. When I go File->New->Package a window similar to a notebook appears, but with different coloration and a row of buttons on the top like 'Update' and 'Run Package'. I'm not ...
1answer
139 views

### ordered tree data structure

I have a map $f:X\to \mathbb{N}$ and I wish to find $x,x'\in X$ such that $f(x)=f(x')$. Since such elements are rare, I will have to check very many elements and perform many comparisons, so I suspect ...
0answers
303 views

### Mathematica shift-enter problem [closed]

Would really appreciate if someone can help with this problem: When I first open a Mathematica note book, say you do 1+2 and press shift-enter. As expected, I get "3" as the output. Now suppose you ...
1answer
70 views

### How can I prevent a package from loading into a notebook run from Workbench?

I have a Workbench project in which I have created two packages: PackageA.m and PackageB.m. In the same project, there is a ...
2answers
124 views

### Write GUI to select spheres in a grid

I'd like to generate a code that: 1) starts with a grid of circles (in general, it won't be a square grid) 2) allows the user to choose some of those circles 3) allows the user to choose the type of ...
1answer
170 views

### Simplifying conditional expressions using assumptions does not work

I have a conditional expression f[x_] := x /; x ∈ Reals This works fine for normal numbers and symbols, e.g. ...
0answers
100 views

### Creating Scheduler

I am trying to build a scheduler program like pizza delivery. Each driver will choose their time and general working schedule will be updated similarly. Problem is number of workers change. How can ...
1answer
258 views

### How to simplify -a*z+a*z to 0 where “a” is an expression

Consider the following: a = 1+(x+y+z+u)^10000 (* Out[57]= 1+(u+x+y+z)^10000 *) e = -a*z+a*z (* Out[59]= z (-1-(u+x+y+z)^10000)+z (1+(u+x+y+z)^10000) *) How can ...
1answer
129 views

### How do you plot polygons with GeoRegionValuePlot?

How do you plot polygons in GeoRegionValuePlots? I'd like to reproduce what the call (2) (below) does with something like the call to (4). As you can see using GeoDisk(s) (3) works but the call (4) ...
1answer
248 views

### Plot multiple curves on the same graph (Color and PlotLegends) [duplicate]

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