0
votes
1answer
8 views

Why cant mathematica solve this non linear (fractional) ode?

a1 = NDSolve[{y1''[x] - 0.1 y1[x]^0.25 == 0, y1'[0] == 0, y1[1] == 1}, I get the following errors - Power::infy: "Infinite expression 1/0.^0.75 encountered ...
0
votes
0answers
6 views

How to evaluate this function with Gauss-Hermite quadrature?

The PDF of a random variable $X$ is given by $$f_X(x)=\frac{2m^mx^{2m-1}}{\sqrt{\pi}\Gamma(m)}\sum_{i=1}^{N}w_ih(t_i)$$ with $$h(t)=\exp\left(-m\left(\sqrt{2}\lambda ...
3
votes
0answers
25 views

Archimedes' Scheme to find $\pi$

Given an Archimedes' scheme $$a_{n+1}=\frac{2a_nb_n}{a_n+b_n}$$ $$b_{n+1}=\sqrt{a_{n+1}b_n}$$ with initial values $a_0=2\sqrt{3},b_0=3.$ How do I prove using Mathematica that this converges to ...
1
vote
0answers
14 views

StringSplit acting weird on a String in StandardForm

To begin, this is my first post on stack exchange, so if my question is not up to par please let me know so I can make the appropriate edits. Now for my question: why is it that parsing a string in ...
0
votes
0answers
19 views

Force NDSolve to use finite difference

How to force NDSolve to use finite difference instead of FEM. I have the following code: ...
0
votes
0answers
20 views

code indent issue in frontend: How to remove annoying space at beginning of a line

I am using MMA 10.4.1 Very often I encountered this problem This is an extraction of a Module (the last bracket is matching module). The ...
0
votes
1answer
17 views

min distance in a graph

How would I find the min distance between two vertices in a graph. What function should I use? For example, in the above, $d(2,4)=2$ and $d(2,3)=1$
0
votes
0answers
20 views

Value Iteration (Recursive iteration) to Minimize (Optimize) a Function

I have a function that I call as "Value". I am trying to find the minimum of this function and this function is a function of 4 other functions. One of these four functions is recursive based on the ...
0
votes
1answer
33 views

Find the minimum element of a row of a matrix and its column index for each row

I am trying to find the minimum value of a row of a matrix and its corresponding column. For instance, I have three functions: ...
2
votes
0answers
27 views

why do python modules load differently via mathematica?

its a steep learning curve trying to integrate mathematica with python's modules/library. I am using a Rapberry pi 3 with mathematica's wolfram command line. I know little about both platforms (so ...
1
vote
0answers
29 views

How to implement reusable graphic components having stable line thicknesses?

IMPORTANT: This post is a follow-up to Scaling edge thicknesses, and in particular to the accepted answer in that thread. Basically, I'm trying to use the idea given in that answer to implement ...
2
votes
1answer
46 views

Projection of a 3d curve to 2d

This question is related to: How to obtain the coordinates of the intersection line of two surfaces? Read the link first. First, I have tried ...
7
votes
0answers
49 views

RandomInteger: speed with long lists

I noticed an interesting effect with RandomInteger when looking at the time to create 10^8 random integers. The following code lines all take about 0.5 seconds on a ...
9
votes
3answers
112 views

Find duplicates in list of InfiniteLine

MMA 10 introduced a new function, which can be very convenient: InfiniteLine. Of course, two infinite lines can be described by different arguments: for example ...
1
vote
1answer
49 views

Mirror image of a point about a line

How can I calculate the mirrored position for a point in 2D space? I know the xy-coordinates of the two points which define the vector. I also know the coordinates for the yellow point which I want to ...
0
votes
0answers
44 views

Nested Tables and List Plot

Take two matrices which depends on three parameters i1,i2 and i3 m1 = {{i1, 0, 0}, {0, i2, 0}, {0, 0, 0}} m2 = {{0, i1, 0}, {0, i2, 0}, {0, 0, i3}} I am using a ...
3
votes
1answer
71 views

Modeling chemical reactions: can Mathematica tell the end result of a reaction?

I am curious about using Mathematica for modelling chemical reactions but don't really know much about the Mathematica software yet. So I was reading this page at wolfram.com which explains some of ...
0
votes
0answers
25 views

Why here does Import[file] produce an error LinkOpen::linke:?

In the folder $BaseDirectory\\Kernel I have a file init.m, who calls a customized initialization package ...
0
votes
1answer
32 views

Using SystemDialogInput in a Manipulate expression

I want to add the select directory function in a user interface such as: ...
1
vote
1answer
131 views

How do you solve a linear equation of matrices?

The function Solve works fine for scalars: In[]:= Solve[A x - x B + C == 0, x] Out[]= {{x -> -(C/(A - B))}} When using matrices however, ...
0
votes
2answers
50 views

Applying a window over a list

The window functions state that they tread over lists, but when I try to do: HammingWindow/@list, I do not get the expected results. What is the best way to apply a window over an arbitrary length ...
1
vote
0answers
30 views

How to enlarge a specific part of a graph using Plot Command?

How to enlarge the closed curves of any Graph and Show them in a separate Graph within the ...
0
votes
0answers
34 views

Eigenelements of conductivity equation

I am trying to calculate the eigenvalues and eigenfunctions of the conductivity equation in an annulus. In particular I am looking for $(\lambda, u)$ s.t. $$ \begin{cases} \Delta u = \lambda u & ...
3
votes
1answer
42 views

Why is `FindCycle` crashing for this graph?

I'm working with a directed graph, previously mentioned in Exporting a high-resolution GraphPlot of a very large graph (65,536 nodes). It can be generated with the following code: ...
6
votes
1answer
135 views

Is it possible to get the (x, y) position of nodes in a `Graph`?

Given a graph... RandomGraph[{20,40}] ...is it possible to retrieve the (x, y) coordinates at which the nodes are drawn? ...
1
vote
1answer
70 views

Evaluate pure function through round brackets

In have some matrices of pure functions or numbers which I multiply by other matrices or vectors. I would like the functions to be evaluated in the result, but all that I get is something like this: ...
4
votes
2answers
160 views

What's wrong with naming a rule?

Please have a look at the code below. The second Manipulate uses the name rl of the replacement rule given in the first line, ...
0
votes
0answers
27 views

Serious Startup Error code: 698 [on hold]

I had Mathematica v10.0.1, uninstalled and installed v10.4.1 on Win10 64x, and now keep getting this very strange serious startup error, any ideas how to resolve it? support is not answering :( P.S ...
1
vote
2answers
56 views

Recreating a ContourPlot3D using points

Let's define a three-dimensional surface ...
0
votes
0answers
22 views

PolynomialExtendedGCD in 2 variables

Consider a field $R$ and the ring $A=R[y]$. Consider two polynomials $g,h\in A[x]$. I want to obtain $d=\gcd(g,h)\in A[x]$ and two polynomials $s,t\in A[x]$ satisfying the Bézout relation: $sg+th=d$. ...
4
votes
1answer
68 views

FInding outliers in multiple dimensions

I'm working on dataset which isn't normally distributed.which contains three dimensions like cost, discount and profit I'm trying to find outliers in all these dimensions. I used z score to find ...
0
votes
1answer
30 views

Option for Simplify command in mathematica

What does Simplify[%[[1]], %[[2]]] mean in following code? I mean [[1]] and [[2]] exactly what does refer to? ...
0
votes
0answers
42 views

Factoring an arbitary variable in mathematica

Imagine we have a equation like this ...
0
votes
0answers
42 views

Generating random numbers using Gaussian distribution in a code and changing standard deviataion in increaments [on hold]

I am working on the following code, which calculates mean2 after taking mean/average over 100 realization of the code with each time 10 random numbers generated using Gaussian distribution. Currently ...
1
vote
1answer
46 views

Is this the right way to use for loop

Is this the right way to use for loop in order to find the sequence of $x_n$ ...
-2
votes
0answers
62 views

unordered lists with maximum dispersion [on hold]

As you can implement the following I have a list $$L = {p1, p2, p3, p4, p5 ........ pn}, n <50$$ I need cluttering and print this list 4 ...
0
votes
1answer
55 views

Boundary conditions for NDSolve

I get the following message: Boundary values may only be specified for one independent variable. Initial values may only be specified at one value of the other independent variable. >> from ...
0
votes
0answers
34 views

Getting DSolve to return different solutions

I am Using 10.0 I am trying to solve the following ODE: $$ \frac{d^2 \psi}{d\theta^2}+ \nu \psi =0$$ , $$\psi(0)=0$$,$$\psi(3\pi/4)=0$$ and Mathematica only sppits out the trivial solution PS: I am ...
0
votes
0answers
27 views

How to remove a hold from a result obtained by equating a partial derivative to 0? [on hold]

I have a function g(x,y). I want to set its partial derivative by $y$ equal to 0, obtain an expression depending on $x$ and use it in further calculations. However, the code I am using puts a hold on ...
0
votes
0answers
47 views

Product of Two Functions

I wrote a little messy conditional probability distribution. In the output, however, the numerator shows like p^2 (A) (B|A), rather than ...
7
votes
3answers
195 views

Deriving a PDF for an annulus distribution

I would like to derive the PDF for an ''annulus'' type distribution, defined by the parameters $\theta\sim U(0,2 \pi)$ and $d\sim N(0,\sigma)$; where $\theta$ is the angle round a circle of radius ...
0
votes
0answers
31 views

Compute the Breslow-Day statistic in Mathematica [on hold]

How would one compute the Breslow-Day statistic in Mathematica? Is it part of an existing package or can it be derived from one?
5
votes
0answers
77 views

Trouble exporting graphics to SVG (or PNG)

I'm trying to export a Graphics object to SVG (or, failing that, PNG). The graphic is a chart of ~1000 simple geometric "configurations"; below is a small excerpt ...
5
votes
1answer
40 views

KaryTree of Text .csv and Correlation

How can I make a KaryTree of this raw-data (raw-data at the end of the question): This is is data from a political survey in which I ask 5 questions with the following possible answers: Q1: 'Y'= ...
2
votes
0answers
72 views

Mathematica gravatar engine?

This question asks about making gravatars in Mathematica, but the accepted answer is just a wrapper around the gravatar.com service. Is there an open source Mathematica engine that performs the ...
1
vote
1answer
38 views

Cartesian coordinates inside Spherical function

I would like to write a function that draws a graphic object and its projections along the x,y and z axes. I specify the $r,\theta, \phi$ of the object and an arrow and it's dashed projections are ...
0
votes
0answers
17 views

How to handle DLL dependencies between .NET dll and non-.NET dll's

I think my problem arises because I am successful with loading a .NET assembly, creating an instance and calling methods from a .NET dll. Certain methods, however, call methods from other non.NET ...
0
votes
0answers
38 views

Integrate fortran function into Mathematica

I was trying to use Fortran function in Mathematica. I was following mainly this answer . My Fortran code looks like this: ...
-1
votes
1answer
44 views

CompiledFunction::cfsa Argument x at position1 should be a machine-size real number [on hold]

I have a compiled function: g:=Compile[{{x, _Real}},...] and call g through an interim function: g2[x_?NumericQ] = g[x] If ...

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