# All Questions

13 views

### How create this plot?

Who can create this ListPlot in mathematica? Who can create this plot in mathematica?
16 views

### Performing an inductive proof

I have an expression which depends on a variable n and am certain it evaluates to 1 for all n with n=1/2,1,3/2,... I want to do an inductive proof that this is true but the actual formula is too ...
31 views

### Logical Circuit

Does somebody know about how to simulate this in Mathematica? I want to give Mathematica the two Inputvalues x,y and it should output c,s. $$c=x\land y$$ $$s=x\veebar y$$ $$x,y\in \{0,1\}$$
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### does exist any group that it's derivation be S3? [on hold]

my question is that does exist any group that it's derivation be S3? at all, when we have a group, how we can find another group that it's derivation be the order one?
42 views

### Two List Manipulation various 10

Sorry bad my English. I have two lists: x-> x list is random integers number of range <0,3> y-> y list repeated range <0,3> and x and y lists as equal Length's. ...
14 views

### Can Mathematica rewrite irreps given in Dynkin Coeffs in tensor form?

Apparently, it is possible to do Young Tableaux calculations with mathematica (see the Susyno and LieART packages). A natural follow up question is then, given that one has decomposed a direct product ...
34 views

### Display trigonometry without Csc and Cot [duplicate]

I have a result with trigonometry functions using Cot and Csc. I would like to keep only cos, sin and tan and so prefer fractions in the display of the results. How is it possible to ask Mathematica ...
18 views

### Disappearing variable in parallel computations

I have a problem with parallel computations. When I try to evaluate formula like this: Do[m[i]=2,{i,1,10}] and then I try to call for instance ...
23 views

### Solver for X - with a function [duplicate]

Sorry but I cant figure this out, Someone gave me some help on here yesterday but they didn't show their working so I could not redo what they did when my equation changed. Can someone please help me ...
87 views

### Two identical functions give different answers

I am new to mathematica and I hope this is a simple problem. I have two identical functions that only differ by the variable names: ...
3 views

### Counting probability problem [migrated]

New to probability I am getting stuck on this counting problem Assuming two numbers are selected at random from a black box with replacement from the integer set {1, 2, . . . , n} and let K be the ...
30 views

### What are all the Properties that ColorData supports?

The documentation for ColorData reads: Possible properties in ColorData["scheme","property"] include: ...
83 views

### Major slowdown when using a ColorFunction with more than one named scheme

Earlier Kuba noted a major slowdown with code Simon Woods posted. Here is a simplified example. First a color function using two different named gradient schemes: ...
59 views

### How to solve and plot this 2nd order non linear ODE? [on hold]

Is this the correct way to plot the solution of this ODE from $(-8, 8)$? $$y'' - (1 - (y')^2)y' + y = 0$$ ...
34 views

### Fredholm integral equations [migrated]

I'm having problem obtaining the solution of the homogeneous Fredholm integral equation of the 2nd kind with a separable kernel. I always get a zero if I use the normal method I was taught for the non ...
25 views

### Mathematica on Linux Ubuntu: antialiasing issue

I'm working on a webMathematica application using a linux server (Ubuntu 12.0.4 LTS) with Xtightvnc. Even though the system administrator has done all the possible to set the anti-alising features, we ...
66 views

### Not seeing plot of solution returned by NDSolve

I am having trouble with generating a parametric plot with the following code: ...
59 views

### How can I convert a Piecewise into a nested If?

For later conversion into a programming language where if is the only conditional construct, I would like to convert a Piecewise ...
41 views

### Solve For X inside arc-cos function (with division) [on hold]

Very basic but I've been stuck for more than 12 hours trying to solver this equation 20=360/(arccos(X/3200)*2) Can anyone solve X? and explain what exactly you ...
31 views

### RecurrenceTable [on hold]

I got an error saying ...
43 views

### How can I import a pickled file?

I have a file generated from a python script that dumped a dataset into a pickle "data.pickle", I am at a loss as to how to Import the file, since "PICKLE" is not ...
24 views

### Assigning some results after a solve procedure to the coefficients of a matrix

I have a matrix M[3,3]. After a solve procedure, I obtained these results. {{M[1, 2] -> Cos[ψ[t]], M[1, 3] -> 0, M[2, 3] -> 0, Cos[θ[t]] -> M[3, 1], M[3, 2] -> 0, M[3, 3] -> 1, M[2, 1] -> ...
21 views

### Extract the divergent/bounded part of a certain expression

Consider I have a power series which is function of $x$. A part of this expression is bounded when $x->\infty$, some remainder is on the other hand divergent when $x$ goes to infinity. What is the ...
66 views

### Extract a part of Series

If I have the output of Series, in terms of powers of my variable $x$, what is the quickest way to extract a part of the series, say for example the terms from $x^2$ to $x^5$, excluding those with ...
20 views

### Extract a term of Series output

Say I have the output of series, with all the coefficients of the different powers of my variable $x$. What is the quickest way of extracting the coefficient of the $n$-th power of $x$?
45 views

### Interpolating a non-continuous set of points

I'm trying to create a pure function that I can feed into OutputResponse[ ] as the input u[t]. In order to do this, I've written code to create a square wave pulse train in the form of a collection of ...
46 views

### How to do n-fold cross validation with Classify?

Other machine learning libraries have utilities to generate indices that can be used to generate dataset splits according to different cross validation strategies. How do I tell ...
36 views

### How to use If to compare a function [on hold]

I'm trying to write a Manipulate demonstration where you can select one of a number of functions. At one point I need to test if the function chosen is a particular one, and it seems to work if the ...
37 views

### Calculating the rank of an abstract matrix

I'm trying to compute the rank of a 4x4 matrix with 4 parameters and 2 variables. I tried to calculate its rank under some assumptions on those conditions and I kept getting rank 4. So I did an ...
21 views

### Somebody imported .mdt files (3d graphics) in Mathematica?

Hello maybe someone did or import this format in math for subsequent presentation in 3D
22 views

### Generating a C/C++ Code with a Non-Linear Vector Function [on hold]

In Mathematica, I have a vector RES = {f1,f2,f3, ..., f7} where f1 thru f7 are non-linear functions of my degrees of freedom: a1 thru a7. I know that I can use: ...
65 views

### Estimating parameters of empirical drag model for predicting trajectory of liquid jet under influence of wind in 3D based on lists of measured data

Also posted here The goal of this is to be able to estimate the drag constants $k$ and $b$ and mass $m$ for an empirical drag model used to predict the trajectory of a liquid jet. Here, the ...
154 views

### How to Map a function with HoldAll attribute

First of all, I'm not sure about the title of this question, so please correct me if there is any title more sensible than mine. The problem is the following: I have a function f that checks if a ...
32 views

### Mathematica not seeing my environment/system variables

I'm trying to access my environment variables in Mathematica, but I get a Failed result every time. For example: $echo$USER jlconlin but in Mathematica I do: ...
45 views

### Infinite Sum with exclusion

From another question I tried to implement something like: Sum[r^(1 - l[n]) DD[n], {n, Complement[Range[1, Infinity], {4}]}] but this does not work because ...
233 views

### Median household income for each county in Maryland

I found that Wolfram|Alpha knows the median household income for every county in the US. I wanted to get a list of all counties in Maryland, and the median income in each county. The only way I could ...
31 views

### Truncate a sum in a 'smart' way

Consider a series like this: $$\sum_{n=1}^{\infty} (c_n r^{2-n/2}+d_n r^{-n/2})$$ Sum[c[n]r^(2-n/2)+d[n]r^(-n/2),{n,Infinity}] I want, now, to keep only the ...
50 views

### Launching 49+ local kernels fails in 10.0.2 [on hold]

I do large-ish parallel computations in Mathematica on quad socket 16 core nodes (64 physical cores). In version 8.x, LaunchKernels[64] works reliably. In version 10.0.2, LaunchKernels[48] works ...
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### html embedded cdf does not print

Upon exporting an nb file to an embedded CDF for viewing in an html file, no print image is displayed when I attempt to print the web page. Given that the CDF Web Development Wizard also produces a ...
67 views

### How to solve a heat flow equation [on hold]

I am a beginner in Mathematica. I was wondering if anyone could give me some pointers as to how to solve following type of equations. During a particular time interval, ...
112 views

I am familiar with regular expressions in other languages (e.g., Perl, Python, ViM), but the Mathematica StringExpression is baffling me. I'd like to match strings ...
41 views

### Don't understand why my Do-loop is misbehaving [on hold]

I have a 2D array, initialized by array = ConstantArray[0, {10, 1000}] and I want to assign numerical values to ...
82 views

### several plots at once

I have several files what i would like to plot at once, they are .dat files and they have names as a numerical sequence from 1 to 4 (they are about a hundred but for the example 4 are ok) so i use ...
39 views

### Series identity with binomial coefficients [duplicate]

I have this apparently simple equation: ...
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### Unknown number of variables in a logical statement

Resolve[ ForAll[{i, y[i]}, Implies[i >= 0 && i < 3 && Implies[i < 3, y[i] > 0], Sum[y[i], {i, 0, 2}]>0]]] returns ...
30 views

### Selecting elements from a list [duplicate]

I have the following array of numbers: a = {{0, 2, 5}, {3, 5, 1}, {4, 0, 5}, {8, 3, 4}, {0, 8, 6}}; then I make a list of the first row with ...
58 views

### CDF of experimental data

Here is data.csv: ...