2
votes
2answers
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 ...
3
votes
1answer
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 ...
0
votes
0answers
42 views

Improving the look of a specific direction field

I wrote: ...
16
votes
1answer
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 ...
1
vote
1answer
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: ...
1
vote
2answers
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 ...
5
votes
1answer
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 ...
1
vote
1answer
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 ...
3
votes
0answers
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 ...
3
votes
2answers
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 ...
2
votes
0answers
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 ...
1
vote
1answer
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 ...
2
votes
2answers
118 views

How to efficiently get a list like this?

I want a function myfun that generates list like this ...
20
votes
2answers
423 views

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

No explanation needed: Maximize[Cos[x + 1], x] Maximize[Cos[x - 1], x] producing ...
1
vote
1answer
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 ...
2
votes
2answers
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 ...
1
vote
2answers
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 ...
2
votes
2answers
93 views

Strange behavior with Show command

I enter this: ...
5
votes
1answer
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. ...
3
votes
1answer
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 ...
17
votes
2answers
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 ...
4
votes
1answer
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 ...
13
votes
5answers
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 ...
1
vote
1answer
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 ...
2
votes
0answers
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: ...
1
vote
1answer
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 ...
0
votes
2answers
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 ...
4
votes
2answers
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 ...
4
votes
2answers
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 ...
2
votes
2answers
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 ...
5
votes
1answer
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 ...
5
votes
1answer
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 ...
1
vote
1answer
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,...
3
votes
1answer
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 ...
9
votes
1answer
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 ...
11
votes
6answers
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: ...
1
vote
0answers
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.
0
votes
1answer
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.
1
vote
1answer
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: ...
0
votes
1answer
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 ...
3
votes
1answer
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 ...
4
votes
1answer
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 ...
5
votes
0answers
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 ...
6
votes
1answer
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 ...
1
vote
2answers
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 ...
3
votes
3answers
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"}} ...
5
votes
1answer
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: ...
8
votes
2answers
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 ...
0
votes
1answer
154 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 ...
1
vote
1answer
87 views

Cannot shade 3D vector in different color

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

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