0
votes
0answers
1 view

Use Solve[] with Bessel, Gamma, and HyperGeom functions?

I need to find values of {a,b,c} such that the 0th, 2nd, and 4th order moments of f[x]=Exp[-ax^4 - bx^2 - c] will equal respectively {1,2,10}. I didn't really expect this to work, and it didn't: ...
0
votes
0answers
5 views

solving non-linear set of equations using NSolve in order to get all roots

vpw = 3.3 Mp = 80 rp = 0.014*Mp b0 = 26.31016273 - (1.7168*10^3/t) - 3.5519*Log[t] b1 = 24.65681838 - (1.547*10^3/t) - 3.4314*Log[t] b2 = 9.080370819 - (6.9445*10^2/t) - 1.2222*Log[t] g = b0 + ...
0
votes
1answer
20 views

how to change parameters in NDSolve?

I want to solve a PDE with parameters chosen based on the sign of derivative. For instance in the following PDE ...
0
votes
0answers
20 views

A question about weighted graphs [on hold]

I need create a weighted graph with given data. Number of nodes: $53$ $\quad$ Number of edges: $91$ ...
0
votes
0answers
16 views

Huge eps file while exporting

I am using Graphics3D and Sphere command to generate a figure. But, unfortunately when I save it as eps file it's size comes up to be ~400MB. What can I do for reducing it?
0
votes
0answers
19 views

Applying transformations to data coming from an STL file

I am very new with the use of 3D graphics in Mathematica, so my question might be very naive. I need to Import an STL file, apply transformations to it (rotation and translation), and export it back ...
3
votes
2answers
86 views

Storing Variables in “Loops” and Point Plotting

Given the function $y=\sin x$ defined over the region $-\pi \leq x \leq \pi$, I need to implement a "do loop" such that I sweep over 100 or so points $-1 \leq y \leq 1$ and find precisely the two $x$ ...
0
votes
1answer
26 views

The FindRoot output only with numbers [duplicate]

I have this code in Mathematica: FindRoot[{Sin[x - y + 2] - x == 0, Sin[2 x - z] - 8 z == 0, Sin[z + y + z] - 2 x == 0}, {{x, 0}, {y, 0}, {z, 0}}] where it's ...
0
votes
0answers
23 views

How do I make a RNG in a function run only when I call the function? [on hold]

In Mathematica, I've made the following function: ...
1
vote
1answer
43 views

Defining a derivative on a custom function

I am trying to define a derivative that acts on a custom function, $f$, such that when it acts, it increments one of the arguments of by 1. f is not defined; I just want to use it to keep track of ...
2
votes
3answers
88 views

Find position avoiding For loop

I have a list: {a,b,c,d,e,f} And a function sizeFunc[element_] which returns the size ...
4
votes
0answers
38 views

How does Dataset compare to DataFrame in pandas?

Pandas is a Python package providing fast, flexible, and expressive data structures designed to make working with “relational” or “labeled” data. Just like ...
1
vote
1answer
26 views

NumberLinePlot: How to make the 3rd list (c) appears with “black crosses” or “void circles”?

a = {1, 2, 5, 2} b = {2} c = {1.75, 2.88, 3.25} NumberLinePlot[{a, b, c}, PlotStyle -> Directive[PointSize[0.032]]] I thought about PlotMarkers or PlotStyle, ...
1
vote
2answers
59 views

Plotting a function with implicitly defined variable

I have a question about plotting a function with an implicitly defined variable. I think the solution should be something similar like here: Define a function with variables linked implicitly but I ...
1
vote
1answer
33 views

Plotting function in cylindrical coordinates (r,theta,z) [duplicate]

I have a function of two variables (r,theta), and I would like to plot it as a surface using cylindrical coordinates. Based on my research, there is no built mathematica function for plotting ...
0
votes
0answers
6 views

Can these steps be converted to a mathematical expression using equations/graph theory/Calculus/Set theory/functions/? [migrated]

Want to convert below algorithm into a mathematical model:- General points 1. Let there be a Connected Directed Graph. G = (V, E) V vertices or nodes E edges. This graph can be seen as a network ...
2
votes
1answer
36 views

Dropping rational coefficients

I have a list of expressions (they all are exact numeric quantities, not containing any variables), some of them have integer or rationals coefficients, or complex coefficients with rational or ...
1
vote
2answers
56 views

Trouble simplifying using Replace

I have the following expression: w.a.b.r+w.c.d.r I want to get: w.(a.b+c.d).r So far I used ReplaceRepeated: ...
0
votes
1answer
47 views

Sum with 2 different variables

I want to plot Contour or Streamplot a function with a sum. The first part (Abs[v/u]>1) looks like this: $L(u,v)=\sum_{s=0}^\infty \frac{(-1)^s}{2s+1} ...
2
votes
2answers
54 views

Gauss Fit to List of 2D Points

I've been trying to find a solution to what I think is a common problem. I have a list of Data like ...
0
votes
1answer
27 views

How to select components selected via SelectComponents?

I have selected the components of a "reduced" (dilated, thinned) image, now I need to go back to the original image and find the coordinates of the components I have found. My code currently does ...
1
vote
0answers
27 views

Accessing the elements of a list of values [on hold]

I have a list of polynomials (all with the variable x) called lyle and a function that accesses this list and evaluates it at ...
3
votes
1answer
162 views

Decode a text which is encoded with UTF-8

I would like to decode a text which is encode with UTF-8. My code is here : ...
3
votes
2answers
176 views

Implementing Picard's Iteration for solving ODEs

Picard's Iteration is a way of solving the IVP $$y'(x)=f(x,y(x)), \quad y(x_0)=y_0 $$ It consists of defining the following sequence of functions recursively: $$y_0(x):=y_0 \\ ...
4
votes
2answers
416 views

Order of a pole

Is there a simple way to determine the order of the poles of a rational function? I have a difficult function where I need Mathematica to find the poles. It would be interesting to also know what the ...
1
vote
0answers
14 views

How to change the MaxIterations option in the neural network method of the predict command

The neural network method of the predict command seems to support a number of undocumented options as shown in a previous question [1]: How to change NeuralNetwork options? Did anybody already have ...
1
vote
1answer
30 views

Use e notation in Stream output [on hold]

I'm trying to save the results of a huge Radia calculation. I evaluate the function in a loop at multiple locations. To export the data my first approach was to fill a Table and use the ...
0
votes
0answers
46 views

The graph of a piecewise function [on hold]

Let $$f(x)=\begin{cases} n,\quad\text{if }\quad n<x<n+\frac{1}{n^3}, \\ 0,\quad\text{if }\quad n+\frac{1}{n^3}\leq x\leq n+1 , \end{cases}$$ Using mathematica, I attempted to draw the graph ...
0
votes
0answers
45 views

How to make the plot smooth

There are some stranges point which cause the figure isn't smooth. I think that the reason is the method of numericial integration. Here is my code, it's pleasure that one can revise the drawbacks in ...
1
vote
0answers
26 views

How to avoid import evaluation until if wil return true

My goal is to import a data from url that depends of 1 parameter, this initialy value is null or undifined en yo have to selec some popup and then the variable has value, what is the method to do ...
0
votes
1answer
38 views

Pure “Select” function over matrix

I have several lists of tuples in the following shape: l1 = {{1, 134}, {2, 314}, {3, 164}} I do want to select, from each list, list elements fulfilling a ...
0
votes
0answers
3 views

Max/Min to logical operator trasformation and viceversa [migrated]

I have some doubts in trasforming conditions that involves max/min in logical operator condition and viceversa. In particular, should be (I put some examples, I would know if I'm right and the ...
0
votes
1answer
28 views

Finding solution of equation with differentials [on hold]

I am trying to find the point of maximum exponential curvature, where the exponent equation is: y = 0.2e^(0.4x) I know the equation for this point is: k = y'' / [(1+y')²]^(3/2) How can I code this ...
0
votes
0answers
32 views

PDE: Inconsistent equation dimensions

I keep receiving an error when trying to solve a 3-D partial vector differential equation. The error states that the equations has inconsistent dimensions. Another problem I am experiencing is ...
1
vote
1answer
40 views

How to apply Simplify only to elements of list that cause specific Warning

I have a set of replacement rules I use to analytically compute nested integrals of very long symbolic expressions since Integrate literally takes forever. To do ...
1
vote
1answer
27 views

Pulling out a prefactor from a dot product [on hold]

I have three complicated vectors u, v and w as well as three simple prefactors ...
0
votes
0answers
22 views

General formula for total derivative [on hold]

I have a real-valued function $f\{x, y(x)\}$, with $x,y\in\mathbb R$. I would like to compute the total derivative with respect to $x$ in Mathematica. However, I am not able to write exactly that ...
0
votes
3answers
34 views

Generating a large table of values and selecting some of them following some condition

I am working on a problem where I have to generate a table of components while each component of the table has 18 entries. Six of the indices among 18 run from 0 to 1 while the other 12 can take ...
2
votes
3answers
207 views

Help with PatternSequence

I have a list of strings of the form list = {str1, str2, strx, str3, .., str10} each string contains both letters and numbers, except for ...
-1
votes
0answers
41 views

Can I get a closed form solution using Mathematica symbolically? [on hold]

I am working on nonlinear equations for my research. I need to use some software to get a closed form solution of the systems of nonlinear equations. Here is just an example: If I want to get a ...
2
votes
1answer
52 views

FindFormula can't deal with the population data from Wolfram server

In the documentation of FindFormula, the first application of it is to predict the population of Poland. ...
-1
votes
0answers
14 views

How to fit a 3-parameter logistic model by R and GLM [on hold]

I have a model follow a 3-parameter logistic model like: $E(Y|x;\beta)=\frac{\beta_2}{1+exp\{(\beta_1-log_2x)/\beta_0\}}$ How can I use GLM to fit this model in R?
2
votes
1answer
119 views

Plot not working for a phase diagram

Whatever I have tried, I could not achieve to plot numerical values coming from my system of differential equation. It is a optimal control model with two state variables. My differential system is ...
5
votes
1answer
67 views

Integrate yielding a ConditionalExpression but I don't think the condition is necessary

Suppose I take the PDF of the LogNormal distribution with parameters m and s evaluated at x. I obviously get an expression involving m. I now want to integrate that expression not with respect to x ...
2
votes
0answers
41 views

Front End does not respond to keys (version 10.2, Linux)

I was often complaining about the front end performance under Linux, but it seems I could pin down a very critical issue. I made a screen-cast that shows how to reproduce the issue Screen-cast on ...
4
votes
2answers
75 views

Factor out the scalar multiplier for the dot product of 2x2 matrices

If yy and zz are 2x2 Hermitian matrices, is there a way that I can mark them (with a property?) as Hermitian so that Mathematica can assume that it can factor out and simplify scalar multipliers from ...
3
votes
2answers
62 views

How do you stack 2D graphics into a 3D graphic? [duplicate]

Suppose you have a series of 2D graphics that depend on a parameter. For example, ...
4
votes
1answer
34 views

How to discover a Java Class Path used by LoadJavaClass?

How can I discover which path is read to load some Java class using the command: LoadJavaClass["my.java.class"]? I believe all ...
1
vote
0answers
45 views

ThermodynamicData missing

Yesterday I was using ThermodynamicData[] and all was fine, today I try to use it and I get: Missing[NotAvailable] Does ...
0
votes
0answers
29 views

Interpreter paclets in temporary directory not being cleaned up

There is a user paclet directory that I inspect frequently because it seems to the source of a lot problems. $UserBasePacletsDirectory ...

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