# All Questions

130 views

### How to rearrange structure and type of an imported dataset?

I have a bigger dataset imported from Excel. Its elements have a form of {time, data}. Day is irrelevant and I would like to have the time in decimal form e.g. 10:30 is 10.5 ...
192 views

### Keeping Font Relative Size to Object/Graphics/Plot Object upon Resize

I want to keep the text generated within a graph/plot to remain the same relative to an element (a disk of size 0.2) of the image upon resize, not the image itself, while maintaining the original ...
42 views

I wrote: ...
360 views

### GeoGraphics: problem with GeoPosition in shifted projections

Bug introduced in 10.0.0 and persisting through 10.4.1 A remark about the answer: My work around is only nice for simple cases with points. More general should include proper polygons splitting on ...
146 views

### Histogram 3D: use different bin width in two directions

I'm trying to plot an histogram of a set of data, I would like to use a bin of different width in x and y direction. I've tried using the following two codes: ...
190 views

### Modular arithmetic in Mathematica? [closed]

I want to implement something like 1 + 1 = 0; i.e., simple modular arithmetic in Mathematica. This seems like it should be a really easy built-in option, but I ...
103 views

### Why does Mathematica remember print settings?

Mathematica has a strange behavior with respect to printing and saving to PDF. It remembers the print settings, such as page range and number of copies along with the file. So if I print 50 copies ...
105 views

### SemanticImport unable to properly read an Excel file with accented letters

Apparently SemanticImport fails to properly import Excel files when accented letters are present in the first (header) row. I'm using Excel 2013 on Windows 8.1 x64 ...
166 views

### Numerical integration: complicated 2D integral seems to be poorly estimated

In the course of some physics research I've been working on, a very annoying integral has appeared that I'm having difficulty evaluating numerically. Any help you could offer would be greatly ...
378 views

### Permanently rounding numbers/values to a given number of significant figures

I am searching for a simple way of rounding and setting an input to a desired number of significant figures. There are a vast number of posts that discuss similar problems, but none address this ...
88 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 ...
98 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 ...
118 views

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

I want a function myfun that generates list like this ...
423 views

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

No explanation needed: Maximize[Cos[x + 1], x] Maximize[Cos[x - 1], x] producing ...
77 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 ...
245 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 ...
87 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 ...
93 views

### Strange behavior with Show command

I enter this: ...
123 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. ...
69 views

### LineScaledCoordinate problem for exact coordinates

Edit: Confirmed bug. CASE:2326540. Still the case in V 10.4. Solution: Wait and use N meanwhile. I've faced this problem ...
650 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 ...
166 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 ...
838 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 ...
64 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 ...
135 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: ...
106 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 ...
273 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 ...
169 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 ...
281 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 ...
213 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 ...
380 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 ...
283 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 ...
40 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,...
261 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 ...
260 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 ...
407 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: ...
76 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.
97 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.
126 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: ...
58 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 ...
195 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 ...
187 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 ...
62 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 ...
213 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 ...
180 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 ...
154 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"}} ...
232 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: ...
155 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 ...
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 ...