# All Questions

107 views

### Problem with grid alignment [duplicate]

This grid works: ...
1k views

### How to make a stereogram in Mathematica?

Given a background and a pattern jpg files, is there a quick and easy way to produce a stereogram by using Mathematica? The following picture was produced from Photoshop, spent about half an hour. ...
1k views

### Solving a nonlinear PDE with Mathematica10 FEM Solver

I am trying to solve a system of coupled nonlinear PDEs in a rectangular region with the new FEM solver in Mathematica 10. However, I come across an error stating NDSolveValue::femnonlinear: ...
48 views

### Is there any way to get Times displayed as $\cdot, *,$ or $\times$ in output form? [duplicate]

In the output of Mathematica, operators $\cdot$ or * or $\times$ are usally displayed as space; e.g., $x * y$ becomes $x \, y$ in output. Is there any option that can be set to make "space" becomes ...
164 views

### Solving a Trigonometric parameter

I have a similar case as given before : Solving a Trigonometric function with one parameter Let: m = 1; Dx = 100; ν = 0.25; b = 1; and, ...
73 views

### Plot failing when given a list of functions

I wrote a code which plots a Maclaurin expansion of cos(x) in various degrees. ...
170 views

### Can $\it{every}$ usage of While be changed into NestWhile?

Ok, I think this problem is more close to philosophy. :P I've some idea now. But I'm not sure whether it's correct. For the purpose of convenience, I will use some C-like code instead of MMA's. A ...
159 views

### Symbolic integration of elliptic functions

Is there a clever way to integrate products of elliptic functions like $\wp(z;g_2,g_3)$ or $\zeta(z;g_2,g_3)$ in Mathematica? Mathematica seems to be able to integrate functions like ...
189 views

### Finding the minimum of a function

I asked this question Mark Minimum Value in DensityPlot. Another question has come up, or better said, a task: Find the minimum of a function. I haven't been able to write the needed code for that, ...
156 views

### How can access to curated data needed by GeoRegionValuePlot be speeded up?

Seems that GeoRegionValuePlot requests data from the internet multiple times to process its plot. As an example, let's graph smoking per capita worldwide. ...
846 views

### GroupBy several keys while keeping the Dataset as a Table (List of Associations)

Assume you import data from a Table source of the following format. ...
361 views

### Generating a polynomial that's accurate to within an error of no more than 1/10^5

I'm currently stuck on a question for class that asks... "Find a polynomial p[x] that you can use to calculate 6 ArcTan[x] to ...
64 views

### Interpolation function evaluation and timing

Lets define two identical functions $f$ and $g$ in a slightly different way ...
165 views

### Inserting rows of one matrix into rows of another matrix sequentially

I have two matrices M1 and M2. Both have same number of columns but different number of rows. I want to make a new matrix M which should have 1st row form M1, second row form M2, third row form M1, ...
190 views

### When plotting vector fields what is the difference between the following?

I am a new Mathematica user, and I have run into a question. What is the difference between the output of the commands: ...
230 views

### Replace all symbols in a matrix with their numbered forms

I have a matrix made mostly from "x" with a few 0's thrown in: ...
125 views

56 views

### Moments Ratio Plot using “ProbabilityDistribution”

I am trying to plot moments ratio plot with the following code: ...
177 views

### The value of an option inside a native function

I'm looking for something similar to AbsoluteOptions but that can be evaluated inside the function. That is, I want to read the absolute settings of options ...
130 views

### What would be a pattern for a general row of an identity matrix?

I know this is a novice question but I would like a pattern for a list containing zero or more zeros followed by exactly one 1, followed by zero or more zeros. Something like: {0___,1,0___} But ...
355 views

### Problem when defining function through NIntegrate and NDSolve and Interpolation - Bug?

More than a single question, I have some doubts about the output of certain functions when defined through the result of other calculations. I am an active user of Mathematica, but maybe I haven't ...
67 views

### How to create a numerically “equal” function?

A simple example about what I need to do. For example, I have three functions: t1[x,t] t2[x,t] t3[x,t] and, ...
464 views

### Mismatch between numerical and analytic evaluation of an integral

I evaluated the following integral $$\int_0^1 \sqrt{r} \left | \cos \left(\left(k+\frac{1}{2}\right) \pi r\right)\right | dr$$ ...
446 views

### ContourPlot - unequal contour spacing

how can i specify the contour spacing or how the color range is distributed amongst the function values? Let's say i plot some function depending on x and y. Function values differ between [0, 1]. I ...
262 views

### unlisting a nested list

I have a list like this: list = {{a,{1,2,3}},{b,{1,2,4}},{c,{{1,4,5,5},{6,3,2,1}}}} This is a nested list which each element has a name. I want to export it to ...
121 views

### Is Mathematica 10 color managed?

With ColorProfileData[] Mathematica 10 can handle device-dependent color spaces. However, images with embedded color profiles, e.g. sRGB, are rendered and displayed ...
121 views

### Removing some data and replacing them with new ones

I have a data list where the elements have the form (time, velocity ). I need to remove some malformed elements in places where the data does not change smoothly and then replace those points by ...
110 views

### Strange behaviour of UpSet [duplicate]

Can anyone explain what is going on here? I want to modify TensorRank for IdentityMatrix, but it fails on its first attempt: ...
132 views

### Quartic equation [closed]

After using Solve I am choosing the physical root of my equation and dealing further with this root. However, when I am changing parameters using Manipulate, I clearly see not smooth behaviour. Is ...
111 views

### Dealing with square roots [duplicate]

Consider following expression: $$\sqrt{-\left(2 \sqrt{x^{-8/3}-x^{-4/3}+1}\, x^{4/3}+5\right) x^{4/3}+4 \sqrt{x^{-8/3}-x^{-4/3}+1}\, x^{4/3}+2 x^{8/3}+5}$$ In code: ...
309 views

### Plot “OilReserves” using CountryData from 1985 until 2014

I am newer using Mathematica to plot with the Function: CountryData, I am trying to plot "OilReserves" in "UnitedKingdom" from 1985 until 2014. I don't know how to do it, please help me!
183 views

### Replace a value in a nested array

When I run the following, ...
143 views

### Why is Mathematica 10 giving me the junk data from Instagram?

Instagram: instagram = ServiceConnect["Instagram"] ServiceExecute[conn,"request",params] sends a request to the connection identified by conn, in my example ...
120 views

### Finding the maximum order derivative of an expression

I have an expression that is the the sum and product of undefined derivatives and their derivatives. e.g. fg+ Dt[f,t]g +Dt[g,{t,2}]f+ What I would like to find ...
136 views

### Create composite key - operating across rows in a dataset

I would like to be able to create a new dataset by extracting 2 columns to make a composite key, and also extracting other columns. For example, suppose my dataset looked like: I would like to ...
86 views

### Take a list with the amounts of the random samples from another list while holding the index

I have a list called cant with some amounts of samples to take from the list community as follows: ...
172 views

### $SU(4)$ Structure constants in mathematica

How can I write a mathematica function which will output arbitrary structure constants of SU(4)?
848 views

### Join two datasets on keys

I want to be able to join two datasets by keys, pretty much like I'd do in SQL. I thought the JoinAcross function might do it, but it doesn't operate the way I thought. The example in the ...
187 views

### Plotting in projective space

I am having difficulty figuring out how to plot to projective space. Suppose I have a region which I have plotted such as: ...
96 views

### Running “Animate” Using a Button

I made the button below for launching an Animate, but it doesn't work at all! Why? ...
208 views

### Maximizing Large Multivariable Function over Region with Parameter Constraints

Brand new Mathematica user here. I have a complicated function to maximize, and thought I would try software like Mathematica instead of taking derivatives by hand. I found some Mathematica ...
439 views

### Solve ODE $d^2u/dx^2 + u/A = 0$

How can I solve following ODE with Mathematical: $$d^2u/dx^2 + u/A = 0 \quad (\text{or } \ C),$$ with the conditions: $$\left.\frac{d^2u}{dx^2}\right|_{x=0} = 0,$$ $$u(x=0) = B$$ and ...
232 views

### First pair out of order

I would like to know how to efficiently determine the first pair of elements in a list that are not in order according to some predicate p. That is, list[i] > list[j] according to p, and i is the ...