# All Questions

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### What is the meaning of Range[10] /. {x_ /; PrimeQ[x] -> x^2}? [closed]

I'm currently doing a unit at university that touched briefly on Mathematica, but the final exam will feature multiple choice questions from Mathematica (along with excel and matlab). This leads to ...
64 views

### Efficient way for solving a matrix equation

I am looking for a more effcient method to perform the following analysis. I did my best, but running the following code on my machine takes 9.766s. I need to perform this analysis several times. <...
79 views

### Problem in solving non linear set of equation?

I am trying to solve a set of non linear equation but using the function nsolve but mathematica is not giving me proper answer. The code is given below. ...
872 views

### Subtracting two plots from each other after shifting one

I have the following lists representing energy spectra that need to be subtracted from each other to produce a difference spectrum. ...
189 views

### Exporting and Importing solution sets from NSolve

I have a rather large data set that I need to solve for, then save to my hard disk and import in the same format at a later time. This proves to be tricky. I use ...
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### FindDistributionParameters and Test Options

This is very much related to my earlier post FindDistributionParameters and Hypothesis Testing. However, I did not get a satisfactory anaswer and it keeps bugging me. I am trying to get help this time ...
198 views

### What is a good way to code long, complex, compilable algorithms?

The functional paradigm of the Wolfram Language used in Mathematica is all around wonderful. For intense numerics, Mathematica comes with the ability to Compile ...
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### Solve for a variable using expression involving sum of quantities

I am trying to solve for h1 using function solve as in below code, Expression in solve equates sum of two expression. Both left hand and right hand side of expression is the sum of four quantities ...
120 views

### What's the difference between functions and replacement?

I used to thought that calling a function is equal to applying a rule, i.e. applying a rule of f[x_]->sth. is equal to calling a function f with definition f[x_]:=sth. However, given ...
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### Isolate graphic components in Manipulate

I have cobbled together two Wolfram Demonstration files to produce the code below. My objective is to generate the phase plane plot on the left side of the output by clicking in one of the regions of ...
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### repeat calculate [closed]

I want　to calculate the below program x[t+1].But I can only calculate t=0,1. please tell me how to calculate t = 0 to 10. ...
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### Solving coupled first-order autonomous differential equations

I am trying to run a simulation of a circuit to observe chaotic behavior, and have obtained a set of differential equations from an analysis of the circuit. I thought perhaps I could produce a plot ...
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### How to Implement a “Function Object” suitable for NDSolve and Finite Element Method?

I have a bunch of methods that shoud return an expression that behave like a function, i.e. an expression that, when supplied with suitable arguments, evaluate to something. A simple ...
157 views

### How to properly generate messages from LibraryLink function?

I'm currently using WolframLibraryData::Message to generate messages from a library function, like this: ...
132 views

### Plot a histogram according to a set of rules using data from two tables

Let's say I have two Tables A={1.0,2.3,1.5,3.0,1.1,} , B={2,10,3,1,0} and I'd like to plot a histogram in the following way: ...
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### How to feed parameters obtained from direct 3D manipulation back into Manipulate's controls?

Here's a simple example of using Manipulate to interactively change the viewer's point-of-view for a 3D graphics object: ...
132 views

### Plotting entries of one table vs entries of another with a condition on a third table

I have three Tables, say, A={1,2,3,4,5}, B={1,2,3,4,5}, C={1.1,2.2,17,1.5,5} of the same ...
64 views

### Setting a range of values to one value [closed]

My question is perhaps worded a little vaguely, but it's a problem I'm running into defining my own function. I'm drawing some shapes with variable height, and sometimes this height is 0. For it still ...
51 views

### Troubleshooting Program Meant to Swap Elements

I wrote a program that is supposed to take a list (of arbitrary length) of pairs of the digits of binary numbers (e.g. ...
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### Make a column of two plots

I'm trying to plot a pair of functions of the same variable one above the other. A simple example is ...
150 views

### Confused by the opts : OptionsPattern[ ] pattern

I'm trying to make sense of the syntax in the clause opts:OptionsPattern[], as found in this standard "rule-based" (pseudo-)function definition pattern: ...
255 views

### What are some useful (or hidden) properties of MeshRegion?

There is quite a bit of powerful functionality built in to MeshRegion, but it seems to be lacking in some areas. For example: extracting a list of edges that live ...
98 views

### SameQ for unsorted lists

I have to compare two or more lists and check if they are the same, but their elements can be in different position. For instance ...
92 views

### Can one upgrade versions directly from Mathematica front end?

The copy of Mathematica I use I get through work. Upgrading this copy is always I time-consuming, pointless chore. I think all of it could be automated. Which makes me wonder: Is there any way to ...
168 views

### Longer ticks without specifying the ticks itself

I know similar questions have been asked here before, but i can't figure out this specific problem. I have a lot of plots that i'd like to bring to a publishable form, but in my current customization ...
80 views

### simplify expressions into sum function

Is there a way to have Mathematica simplify long expressions involving sums of variables into expressions using a sum function? Suppose I have something like this: ...
136 views

### How to remove the list bracket in some expression?

I have two problems with the List bracket {}. First, I want to get a specific component of LeviCivitaTensor, so I should use ...
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### How to change the texture of the graphical objects? [duplicate]

I would like to make a number of 2D figures with Graphics[] command, e.g. Disk[], Rectangle[] etc. It is easy to change the colour and opacity, but I would like to have the internal area shaded with ...
154 views

### Find fit does not find the best fit

Here is my data ...
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### Powerset Animation/Invisible Vertices/Graph Layout

I wanted to visualize the cumulative powerset construction process and came up with two functions: ...
153 views

### How to plot a quarter disk with specified height?

Kind of important: the solution posted does work, and answers the question in that sense. However, it is very slow, so a faster option would be much appreciated. I'm trying to create the following ...
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### Is it possible to extract data from an eps plot not generated in Mathematica?

I want to extract data from an eps plot not generated in Mathematica and replot it. In general is it possible to extract data from plots in any formats in Mathematica? I searched but unfortunately ...
431 views

### Laplacian and DiracDelta

It is known that: $\nabla^2 \dfrac{1}{|r-r'|} = - 4 \pi \delta^3(\vec{r}-\vec{r}')$. If I do that with Mathematica, I find: ...
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### How to speed up Select with MemberQ for large lists?

I have two large lists: list1 and list2. I would like to select elements of list1 only if they appear in list2. Since the list1 has dimensions of (335000, 2) and list2 : (122000, 4), it's taking a ...