0
votes
0answers
74 views

Solving for a variable within a definite integral using FindRoot

I want to solve for P in this equation: Integrate[1/((P/(M*V)) - r*g - c*A*(V^2)*p/(2 M)), {V, 0, 26.82}] = s , where all constants are given except P. I've ...
4
votes
1answer
80 views

RandomSample Bug?

I was using RandomSample with very skewed weights. I am asking for a random sample of 6 numbers 1 through 100 without replacement. In the screen shown, the weights for 1 through 6 are 100 000, with ...
1
vote
0answers
46 views

Type Vietnamese in Mathematica

I type Vietnamese using UTF-8 Encoding but Text Display got error. How to type Vietnamese, Chinese in Mathematica. Please help me.
0
votes
1answer
53 views

Optimise CPU-intensive list combining function

I have a list of numbers list1 from which I want to create another list (list2) consisting of only those numbers that are equal ...
3
votes
1answer
126 views

Set Image Size and Page Orientation When Exporting to PDF [duplicate]

I want to export my plots (plot1 and plot2) as a pdf file. Since plot1 contains 4 figures in matrix form, so it will not fit in one page. ...
2
votes
2answers
400 views

Integrating a Simple Piecewise Function

If I define f[x_]:=If[x<0,-1,1] and then integrate,say Integrate[f[x],{x,-3,7}] I get what I expect, namely 4. But ...
1
vote
3answers
122 views

Gather lists according to another list

I have a first list of pairs like this one: ...
0
votes
1answer
124 views

How to plot a decahedron with Mathematica?

I wrote Graphics3D[{Opacity[.9], FaceForm[Yellow], PolyhedronData["Dipyramid", "Faces"]}] and I get this picture: I would like to plot a decahedron without ...
1
vote
0answers
64 views

Why has my syntax coloring changed?

Local variables in Module are no longer specially colored for me, but other syntax coloring remains, for example iterators in a ...
-3
votes
1answer
59 views

Find the coefficients of a set of expressions in partial-derivatives [closed]

Is there a way to find the coefficients of these (terms within the square brackets) expressions using mathematica? \begin{align} \hat{l}^2=&\sum\limits_{a=1}^{4}\left[\left(\frac{\partial ...
0
votes
0answers
56 views

Generating the set of all three-dimensional binary arrays distinct under rotation and reflection?

How can I automatically generate all possible three-dimensional binary arrays of size $(x_1 \times x_2 \times x_3$) where each array is distinct from all others with respect to rotation and reflection ...
0
votes
1answer
68 views

Generalizing Characters to n-character substrings [duplicate]

I'm doing some frequency analysis on an encrypted plaintext. Tally[] and Characters[] make the basic task quite easy. To count the number of times each character appears (sorted alphabetically; ...
-6
votes
1answer
123 views

Poincaré section for 3BP

I try to plot the Poincaré section for the 3BP i use the following code that works very well: ...
0
votes
0answers
196 views

NDSolve::ndsz:At t==0.000039576, step size is effectively zero

I adjusted my code accordinly to the advice I got. However I still have a problem with this code which now looks like this: ...
2
votes
0answers
45 views

Autocomplete from inside Module and SetDelayed

Autocomplete in Mathematica 9 offers suggestions from inside SetDelayed and Module. For example, after running: ...
5
votes
1answer
265 views

Fit data with linear combinations of Cos and Sin

Recall that if $f$ is a piecewise continuous function on the interval $[-\pi, \pi]$, then the Fourier series of $f$ is $$f(x) = \sum_{n=0}^{\infty} (a_n \cos(nx) + b_n \sin(nx)).$$ See for example, ...
4
votes
3answers
229 views

Notation package: parenthesis placement for SuperscriptBox

The question concerns the Notation package. I want to define notation for the function very similar to the built-in Power[a,b] ...
12
votes
2answers
224 views

Result about Context is inconsistent with the description of “Power Programming with Mathematica”

x = 5; temp`x = 6; Begin["temp`"] {x, Global`x, temp`x} The result in my Mathematica session is {5,5,6}, but it's ...
0
votes
2answers
142 views

How to numerically integrate this integral?

I want to integrate the function funcin (spherical coordinates). ...
1
vote
1answer
108 views

Integrate with FunctionInterpolation differs from NIntegrate

In working with interpolating functions and integration, I noticed a lot of differences between NIntegrate and Integrate in the ...
3
votes
1answer
185 views

Extracting function calls from an expression

I have an expression like this: expr = F[0, 1] + 2 F[0, 0] - 17*F[2, 0] and I want to transform it to a list consisting of all function calls with its arguments: ...
1
vote
1answer
93 views

Custom highlighting in definitions

Suppose we defined a pattern with custom pattern name provided by user, like Quiet[myCustomPattern@terms_ := f[terms : (_[_, _])..]] for use in further ...
0
votes
0answers
35 views

How to plot data of complex numers [duplicate]

Here I have some output calculated for different values of some parameter. I want to plot these points in complex plane Re, Im and present them with ListLinePLot. How can I do that, I tried many times ...
2
votes
1answer
149 views

Breaks in plot & blank plots

Almost as a follow on from this old question, I am having similar problems again, with slight difference, that if the values are small enough, a completely blank plot is produced. ...
3
votes
1answer
78 views

Where do Mathematica's probability functions draw a line in the sand for predicates?

Thinking about a recent question mis-posted here (belonged on math), I noted the following. A contrived example - probability that a or b are 1: ...
4
votes
1answer
260 views

MATLAB to Mathematica: coneplot

Does Mathematica have a function, similar to the one called coneplot in MatLAB? Given some spatial coordinates $x, y, z$ and velocity components $v_x,v_y,v_z$, it ...
0
votes
0answers
56 views

g00 (metric tensor) not explicitly evaluated in FeynCalc

I am learning Mathematica and FeynCalc by doing some basic cross section calculations. I have an issue with trace calculations: When I plug in for instance the ...
2
votes
4answers
229 views

Working with symmetric polynomials

I have a question related to working with symmetric polynomials in some variables. Let us say, I have an expression ...
9
votes
1answer
299 views

Generating high quality charts in Mathematica for use in LaTeX and Word

I frequently have a probelem using my charts in reports because the text (axes labels and tick marks) look low resolution (fuzzy). When I export my charts, i export them as PNG files. Unless I'm ...
0
votes
1answer
69 views

Variance/Standard Deviation with a Constant Vaule

When applying variance (Variance[10]) or standard deviation (StandardDeviation[10]) to a constant value in Mathematica, Should ...
0
votes
1answer
89 views

Plotting the discrete solution to a PDE

So I went through all the grunt work of solving a PDE in discrete form for a research project. Now I have a Temperature solution as a function of time and space: $$ T_{i}^{n+1}=\left( \dfrac ...
0
votes
0answers
175 views

How to obtain differential equations of motion using Lagrangian dynamics?

I'm confused to find a set of differential equations of motion of a pair of masses, m1 and m2 joined by a spring of constant ...
0
votes
0answers
77 views

How to mathematically represent MMA 9 Spikey?

I am trying to figure out how to mathematically represent the MMA 9 Spikey in order to send to a 3D printer. According to this page, " In particular, spikeys for version 2 and up are based on a ...
0
votes
1answer
36 views

How do I pull from a data list for parameter values in a system of ODEs and then solve and plot?

I have a parameter set list and I would like to solve a system of ODEs multiple times using each parameter set in the list. Then I would like each set of solutions to be graphed on the same plot. ...
0
votes
1answer
74 views

grid lines in Manipulate plots are not showing up when first rendered?

I have a Manipulate within which the plot does not render completely initially: ...
0
votes
3answers
288 views

Draw generalized k-ellipse using “the locus of points so that sum of the distances to the foci is constant” deffinition

My goal is to draw a family (for different distances) of 3-ellipse for equilateral set of foci. 3-ellipse definition is: "the locus of points so that sum of the distances to the three foci is ...
0
votes
2answers
120 views

Replace matrix with conditions

I want to replace the values of 1. in slot under the condition that the year and month in basevalue and ...
6
votes
2answers
101 views

Algorithm in RandomChoice[{w1,w2,…}->{e1,e2,…},n]?

I wonder if someone happens to know the actual algorithm implemented in the particular overload of RandomChoice that handles explicitly presented discrete ...
-1
votes
2answers
119 views

Plotting solutions of differential equations with different parameters

I want to plot x[t], when i manipulate w from 0.1 to 1.5. Here is what I've attempted, which does not work as expected. ...
0
votes
0answers
61 views

How to solve an inequality

I am trying to solve the following inequality: Assuming[{R[k] >= 0, R[k + 1] = R[k] - 2^N Y, Y >= 0 && N >= 0}, Refine[Re[R[k + 1] >= 0]] I ...
1
vote
1answer
122 views

Skewness of distribution vs. skewness of distribution's PDF

I'm having trouble understanding why the skewness of built-in distributions is not the same as the skewness of their probability density functions. For example, the following are different (the first ...
0
votes
1answer
79 views

Plot graphs in different colors

I am generating a set of plots and exploring how changing a parameter affects the plot shape. I want each plot to be a different color, but the color rule i'm applying seems to only work for the last ...
1
vote
2answers
78 views

I'm trying to filter a date range by day of month and day of week - what am I doing wrong?

I am trying to generate a list of dates that match two criteria: they have to all be the first of the month, and they have to be a particular day of the week, Sunday in my case. The code I have ...
1
vote
2answers
171 views

intersection between function and plane

I try to solve a ODE system of equations and i want to plot the intersection of the 3D solutions with a costant plane. To do this i use the follow code: ...
0
votes
0answers
45 views

NSolve or Reduce for obtaining the results and connecting roots

Here I have one problem how to solve numerically equation for different values of one parameter x. I used just two digits because of length, but for x=0.57 I should have one real root and for others ...
8
votes
1answer
173 views

Why does Plot[Hold[x], {x,0,1}] work?

It appears that, counter to my expectation, all of these (and probably many others) seem to work fine: ...
2
votes
2answers
166 views

Converting from TableForm to Grid

I wonder if there is an easy way to convert from TableForm to Grid. I have an existing data format that uses the Table function that I’d like to prettify…. Let’s setup a nested table as follows: ...
2
votes
0answers
67 views

Assign a value to a variable without using Set or SetDelayed?

I supose probably yes, but at the end I assume that internally mathematica has to use Set or SetDelayed. Am I right? Background: I am developing a super simple phraser that takes a code description ...
0
votes
0answers
104 views

Boundary Condition Problem with Green's Function

My temperature distribution looks like: Mean wire temperature is : To[x_] := 2 c1 Cosh[x a1] + a2 And it is continuous at two points. In positive part: ...
2
votes
0answers
97 views

How is Wolfram Language different than regular Mathematica? [duplicate]

From all I can see there seems to be no difference between "Wolfram Language" and regular Mathematica. Is Wolfram just a marketing rebranding of Mathematica or is there a new capability I am missing?

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