4
votes
1answer
314 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 ...
2
votes
4answers
248 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
361 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
82 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
113 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
250 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
114 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
45 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
97 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: ...
1
vote
3answers
389 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
184 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
121 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
206 views

Plotting solutions of differential equations with different parameters [duplicate]

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
72 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
182 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
99 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 ...
2
votes
2answers
107 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
295 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
54 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
214 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
289 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
71 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
137 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
104 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?
4
votes
1answer
140 views

Import YAML file into Mathematica

Has anyone implemented the import of YAML data files into Mathematica? I suppose some sort of transformation into a nested list of rules would be the way to do it. Thanks
1
vote
1answer
179 views

Plotting a list in real time

I would like to use Mathematica for a presentation and have a list plotted in front of my audience, one coordinate at a time. How would I go about plotting a list progressively in real-time, ie the ...
3
votes
1answer
483 views

Categorical Distribution

Suppose I want to do calculations with a random variable $X$ that has a simple categorical distribution (a.k.a generalised Bernoulli distribution or discrete distribution). I was expecting to be able ...
2
votes
2answers
102 views

Merging two held expressions into a held compound expression

Consider e1 = Hold[a = x + x; b = y + y + y]; e2 = Hold[c = a + a + b + b + b; c^2]; How can I obtain the following? ...
2
votes
1answer
160 views

Order of symbols in Graphics labels

Do you have any idea how to force an order of Greek letter in the graphics? When I type in AxesLabel -> {Cost, Δ OverBar[π]} the order is π Δ. How can I ...
1
vote
1answer
620 views

Why Mathematica can't solve this? NSolve or Solve

I want solution of x and y which should be positive real numbers ...
2
votes
1answer
492 views

2d heat conduction equation: Boundary and initial conditions are inconsistent

I have the following code for a 2d heat c equation: ...
1
vote
0answers
92 views

Define inverse for the custom operator

I want to define simple matrix algebra (inspired by the following posts: Block Matrix Algebra with Mathematica ; How to define custom operators ). I assume the funtion ...
1
vote
1answer
223 views

GatherBy and two conditions

I have a list of 4 dim points, given by ...
1
vote
3answers
229 views

For loop in Mathematica

I have set of statements ...
0
votes
1answer
65 views

Solve equation with two different sets of replacement rules

I want to solve eqn for c0. I want to do it with both replacement rules. I realize I could just use solve twice, once for subsCoke, and once for subsPepsi. I'm trying to do it in just one Sovle to ...
1
vote
0answers
68 views

Problems with manipulating plot in a dialog

G'day, guys. Here is a silly problem I am struggling with. ...
2
votes
1answer
143 views

How to find the zeros of a Complex trigonometric function

I tried this ...
0
votes
0answers
233 views

Shooting method for solving 3rd Oder ODE with RK method

This is my 3rd Order IVP. D[y[x], {x, 3}] == (m/2)*((D[y[x], x])^2 - 1) - ((m + 1)/2)* y*(D[y[x], {x, 2}])^2. Initial conditions given are as follows ...
0
votes
3answers
423 views

Find an equations of motion using Euler Eqution [closed]

I am a completely new to Mathematica, so my question and code may look silly. I need to find a equation of motion of a point particle of mass m moving in a potential V(x) = A abs[x]^n. (n=1,2,3,4,5,6. ...
4
votes
3answers
518 views

Why is my solution to PE #5 so slow

I'm new to Mathematica and it was suggested to me to go through the Project Euler problems in order to learn it. However, I can't quite figure out why my solution to #5 is so slow. The problem: ...
0
votes
1answer
229 views

Why can't Mathematica solve this system of equations?

I am trying to solve the following system of equations for three unknowns Theta, Nu, and K. All the other parameters are constants. The third argument in Solve, ...
1
vote
1answer
117 views

BlockRandom and NestList: how get random maps with the same noise?

I need to compare solutions in random systems with the same noise and different initial conditions. Here I run twice a random map with the same initial condition, inside a ...
1
vote
1answer
65 views

Commutative algebra by generators and quadratic relations

My apologies if this has been asked before. Please also be gentle, as this is my first question here. I am trying to define a commutative algebra by generators and relations in the following way. ...
1
vote
0answers
68 views

Manipulating infinite series

If I type Sum[f[x],{x,m,Infinity}]-Sum[f[x],{x,m+3,Infinity}] I would like Mathematica to return something like ...
3
votes
0answers
323 views

Masked Image Registration/Alignment/Correlation

I'm trying to register (align) two circular grayscale images using a boolean mask to prevent them simply being aligned on the fixed circular border. There are also small fixed circular regions in the ...
0
votes
0answers
46 views

Aborting Multiple Trial Divisions if a Factor is found

I am using Mathematica to perform trial divisions on large Mersenne numbers using specific prime numbers (e.g., primes of the form 8n+1 or 8n-1) and would like the program to abort once a factor is ...
3
votes
1answer
79 views

Complex LogIntegral error

Going through Derbyshire's Prime Obsession & trying to take LogIntegral of 20^ZetaZero[1] & comes up with a value of ...
4
votes
1answer
888 views

NonlinearModelFit does not find a good fit

I am trying to fit my data to the following function, $$\frac{a b t \left(\log \left(\frac{-a d t+a t-1}{a d t}\right)-2\right)}{4 (a t-1)}-c$$ ...
1
vote
0answers
95 views

Increase optimization processing speed

As you know, sometimes numerically solving of optimization problems takes several minutes. For this reason 2 question came up to me: 1 - When one is abort the optimization procedure, how it is ...
4
votes
1answer
75 views

Control Object Annoyance

This may seem like is a trivial annoyance, but it really is a control object "convenience of use" issue. Example: I want to use a popup menu to determine which Excel worksheet I take data from, as ...

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