All Questions

0answers
2 views

Minimum and maximum values under conditions

Let's create some sample data ...
0answers
3 views

Is doplot a command in Mathematica?

I am just beginning with mathematica and I have received this code to understand. I am not able to follow this particular section. I have tried looking it up on many forums, with no answer. Can you ...
1answer
14 views

Is it possible to plot a second-order curve by its non-canonical equation?

I have this second-order polynom: $$6xy+8y^2-12x-26y+11=0$$ And I need to reduce it to a canonical form of a second-order curve. I solved this, but is it possible to draw a plot of the original ...
0answers
19 views

How to automatically plot asymptotes?

I'm a newbie to Mathematica and I'm reading through "The Student's Introduction to Mathematica, Second Edition" and am on the "Using Mathematica’s Plot Options" section of chapter 3. The examples for ...
1answer
26 views

How do I solve for one variable in terms of other variables in Mathematica?

I'm fairly new to Mathematica, and I'm trying to solve a complicated equation with multiple variables. I've tried the following... ...
1answer
22 views

Elements in Reap and Sow

Can someone help explain it to me: How does here e come out? Why b disappears? ...
0answers
21 views

GUI->Text code conversion

I have to solve about 30 symbolic equations simultaneously. Mathematica is taking more than 24 hours to solve it on a 6 core system and now I have to run that on a cluster. In order to do so I need to ...
1answer
25 views

How do I constrain variables to a user-defined domain in ArgMax?

I am trying to ArgMax a function over x, but x is only defined between ...
4answers
74 views

What is the natural way of using Dataset to get a FittedModel?

The new Dataset in Mathematica 10 is a great addition to the language, potentially reducing the convenience gap with R. Given this, I would like to understand what the equivalent simple or natural ...
1answer
46 views

Express a complex function $f(z)$ as $u(x,y)+iv(x,y)$

How can I write a complex function $f(z)$ in the form $u(x,y)+iv(x,y)$ using Mathematica? Re and Im do not work, because they do it for complex numbers, not functions. For example, if I try ...
1answer
57 views

Integrating Mathematica in Blackboard

I teach Economics at University. I often use Mathematica to generate interactive diagrams with demand and supply curves. We also use Blackboard (blackboard.com) to manage our subjects, including ...
0answers
19 views

What to do when an “error-free” compiled function uses MainEvaluate?

Consider the following code: ...
1answer
47 views

Manipulate gives the output as a blank plot, but I'm not sure why

I'm using Mathematica 9 to try to manipulate a 3D plot. My code is: ...
2answers
45 views

How to insert zero counts uniformly with Dataset Counts query

Missing[] is generated when an association does not contain the specified key. ...
5answers
105 views

Creating a new list by dropping sub elements of the original list

Suppose I have a nested listed as follows, {{{1,2},{3,4,5},{2,3}},{{2,3,4},{5,4,1},{1,4,3}},{{3,4,5},{3,4,5}}} Where the elements are, ...
3answers
88 views

Using select to pick out elements of nested lists in an odd way

Suppose I have a nested list such as, {{{A, B}, {A, D}}, {{C, D}, {A, A}, {H, A}}, {{A, H}}} Where the elements of interest are, ...
1answer
33 views

How can I append associations with uneven elements? [duplicate]

My dataset is pretty simple so far: ...
0answers
57 views

Symbolic matrix calculus: What's new in Version 9

I have seen some of the related posts, which ask about doing matrix calculation on tensors unknown dimensions. One of the posts mentioned that version 9 has some capability, but it was concerned about ...
2answers
44 views

Exporting an overlay of two plots

I have a ListLinePlot and I'm trying to place a close-up of a specific range in the ListLinePlot. Using overlay I solved this problem with: ...
4answers
235 views

How to create a screen shot of a notebook

I would like to use Mathematica programmatically to take snapshots or screenshots of any open notebook. For example, I would like to get from the notebook created with this command ...
3answers
148 views

Sum with Levi-Civita

I'm trying to write the expression $$\sum_{\alpha,\beta = 1}^{4}\epsilon_{\mu \nu\alpha\beta}a^{\nu} b^{\alpha} c^{\beta}$$ in Mathematica, where $\epsilon$ is the Levi-Civita symbol and $a$, $b$, $c$ ...
2answers
43 views

why the variable scope is not local when using evaluate to plot multicurve?

I noticed a surprising problem when using evaluate to plot multicurve, "evaluate" function actually consider global variable first, not the local! I can illustrate the problem using the following ...
0answers
42 views

NDSolve fails to solve vector-valued function x'[t]=a.x[t]+u.b

I get no solution when I run the following command: NDSolve[{x'[t]==0.{{0},{0},{1.}}+{{0,1.,0.},{0,0.,1.},{0.,-0.156816,-0.523512}}.x[t],x[0]=={0,0,0}},x,{t,0,1}] ...
2answers
300 views

Is there a function for nearest power of 2 in Mathematica like nextpow2 in MATLAB?

I am looking for something like nextpow2 in MATLAB like this: P = nextpow2(A) returns the exponents for the smallest powers of two that satisfy $2^P \geq\left|A\right|$.
0answers
50 views

Check for holomorphy of a function

Given a (rather complicated) function H(z), what is the best approach to check symbolically whether it is holomorphic? What I tried is checking explicitly the Cauchy-Riemann equations: ...
3answers
88 views

Intersection of lists of disjoint intervals

Here is my problem: I have two very large lists of intervals (stored as many couples in the form {{"start point", "end point"}, ..., {"start point", "end point"}), ...
1answer
48 views

FindDistributionParameters of a sum of a mixture distribution

I have this Mixture Distribution of two Normal Distributions: ...
0answers
19 views

Is equation numbering in exported HTML considered deprecated for built in stylesheets?

So I've been tinkering around with the built in stylesheets and the Export command and I've noticed that in principle equation numbering should work. When you look ...
0answers
30 views

Needs entry point of a package from a Mathematica script

I am writing a bunch of Mathematica scripts to run command line in a HPC environment. I am organising my solution in small chunks I can test separately. So I have a directory structure like: ...
2answers
82 views

Solving an Equation (Recursively)

I have the following Values: $a[0]=1;a[1]=0;a[2]=0;a[3]=0;a[4]=\frac{g_2}{20};a[5]=0$. I need to compute the value of $b[n]$ in the following equation a[n]=\sum _{m=0}^{n} (m-2) \;\;a[m] ...
4answers
157 views

Controlling the placement of the y-axis

I use ListPlot for showing the results of my numeric computation. I make my own ticks, so I never know before hand where the vertical center of my plot will be. ...
1answer
47 views

Changing Wolfram command line output into copyable text

I generated a long polynomial using the Wolfram command line, with divisions and exponents. But the divisions look like this: 4 - 5 And the exponents are on a ...
0answers
58 views

Developing easy code to apply Delta Method to generate prediction bands for custom distributions

I think that this is an interesting issue for all those who when to not only adjust one prediction function, but also to obtain the prediction bands to asses the graphical or tabular error I'm trying ...
2answers
64 views

Piecewise Polynomial Interpolation

Given some data pairs $(x_i,y_i)$, with $i=0,...,m$, and a degree $r$, I wish to build a piecewise polynomial function to interpolate these data. That interpolation should be continuous, and, on every ...
2answers
64 views

ColorFuntion input

Is there any input for ColorFunction, which ranges from Black for smallest values, goes through red-orange-yellow and ends in very bright yellow almost white for ...
1answer
65 views

How do I solve for the real and complex parts of an equation simultaneously?

If I were to have an equation, say something similar to... (1-Sqrt[x - I y])/(1+Sqrt[x - I y]) = A + I B Where I = Sqrt[-1], is there a way for Mathematica to ...
1answer
137 views

why Level does not sort output according to their levels

Consider this example: Level[a + f[x, y^n], {0, Infinity}] (*{a, x, y, n, y^n, f[x, y^n], a + f[x, y^n]}*) Why the output is sorted in this way. why not ...
1answer
51 views

Inclusion-Exclusion Principle Implementation

I would like to know how I can write a Mathematica code for the Inclusion–exclusion principle. The formulas governing it are: \$ P(\bigcup_{i=1}^n A_i)=\sum_{k=1}^n (-1)^{k-1} ...
1answer
70 views

Key->Value or Value when returning (multiple) parts of an Association

There seems to be an idiom whereby multiple parts generates Key->Value forms whereas for single part specifications, only a Value is returned. This however, can lead to inconsistencies as follows: ...
2answers
136 views

Using ReplaceAll to replace a head

Why would this work to replace the head b with newHead: ...
0answers
111 views

Learning Resources for Data Science in the Wolfram Language

I'm delivering an upcoming course on Data Science with the programming/analysis done predominantly in the Wolfram Language. I created the following table to leverage students' familiarity with Lists ...
1answer
50 views

Why can NSolve only solve this system of equations after trivial substitution?

The first system immediately yields {}, but the second, equivalent, system yields the solution {{k -> 4.96048, tl1 -> 1.64842, tl2 -> 2.07466}} : ...
0answers
29 views

What is that Root[…] inside the answer represent? [duplicate]

So I am encountering this situation, in which mathematica doesn't give me the answer, but in a form of "Root". How do I interpret this ? what is the number after the "&" represent? How should I ...
0answers
100 views

Undirected Network and its Monte Carlo Simulation

So I have this array of points, in the form {x, {y,z}}, where x is the node number assigned when I used the locator pane to make a network, and y and z are its unitary coordinates. The graph is made ...
1answer
84 views

Interpolation function rejected by ParametricPlot3D

I was playing around with the bouncing ball example, and decided to make a 3d version. I decided to use ParametricPlot3D for a simple independent 3D ...
0answers
44 views

How to handle infeasible points in FindRoot?

I am calling FindRoot[f[x,y],{{x,xInit,xMin,xMax},{y,yInit,yMin,yMax}}] where for some points {x,y}, ...
2answers
138 views

Probablity weighted ReplaceAll

I'm looking for an elegant way of doing a probability weighted replacement rule, something like this ...
0answers
143 views

Given f[1] … f[k], k = 1, 2, 3… how do one find the general function f[n]?

If I have that ...
1answer
61 views

why head Association cannot be replaced by head List [duplicate]

Consider replacing head of List by head Association: {a -> x, b -> y, c -> z} /. List -> Association (*<|a -> x, b -> y, c -> z|>*) ...
0answers
37 views

Plotting and NIntegrate [on hold]

I have a problem. I try to make such a plot: function = y^(3/2)*Exp[I t y - y^2]; Plot[NIntegrate[function, {y, -∞, ∞}], {t, -20, 20}] But I have no plot - I ...

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