All Questions

0
votes
2answers
276 views

Plotting geodesics of upper half plane

I want to solve (numerically) the geodesics of the upper half plane and plot. The results are quite known (i) straight lines parallel to $y$-axis and (ii) semicircles centered on the $x$-axis. Now the ...
13
votes
1answer
161 views

Why changing list's head takes time?

Consider AbsoluteTiming[Range[10^7];][[1]] 0.035000 and AbsoluteTiming[HoldComplete @@ Range[10^7];][[1]] ...
4
votes
1answer
503 views

Recursive Integration

I'd like to evaluate the following recursive integration using Mathematica $$ \ M(T) = \int_0^T\int_0^\infty e^{-\delta s}g(x,s)dxds\ +\int_0^T e^{-\delta s}f(s)M(T-s)ds\, $$ where $g(x,s)$ and ...
4
votes
1answer
66 views

Optimizing List Multiplications

I've got a list manipulation optimization problem. Consider a two-dimensional nxm list list1, and a three-dimensional nxmxm list, ...
4
votes
2answers
547 views

Inverse of a polynomial in a polynomial ring

Let $N$ be a prime, and $q$ be a positive integer. Given a polynomial $f(x)$ in $R = \mathbb Z[x]/(x^N-1)$, I want to find another polynomial $f_q(x)$ in $R_q = \mathbb Z_q[x]/(x^N-1)$, such that ...
2
votes
1answer
74 views

Why do I have to perform a second ReplaceAll in this InterpolatingFunction?

I have an InterpolatingFunction that I'd like to plot, and I wonder why I have to perform a ReplaceAll on the following function: ...
7
votes
2answers
404 views

How to declare a 3D vector variable?

How can I do vector calculations without telling Mathematica the vector entries? I have very many arbitrary linear combinations in $\mathbb{R}^3$ which I want to perform some general calculations on ...
4
votes
1answer
182 views

AstronomicalData and Planetary Heliocentric (x,y,z) Velocity Components

I'm trying to find data on the heliocentric velocities of planets in our solar system and was directed to Mathematica's AstronomicalData in a previous topic. ...
2
votes
0answers
261 views

Forecasting future Stock Prices II

I intend to do the following: I want to forecast future stock price under the following assumptions: The stock price is governed by the stochastic differential equation: dS = μSdt + σSdWt whereas ...
18
votes
4answers
849 views

How to calculate the volume of a convex hull?

Given a spatial curve represented by a parametric equation, is it possible in Mathematica 9 to calculate symbolically (or at least numerically) the volume of its convex hull?
4
votes
1answer
310 views

How does Mathematica calculate the nth prime?

When I enter Prime[2000000000000], the two-trillionth prime, Mathematica gives 61427839512211 for the answer after several ...
1
vote
1answer
148 views

Improving the plotting time of a very complicated expression

The quatity $R$ is defined by a complicated expression in terms of $a_1,a_2,\ldots,a_n$. Now each $a_i$ is a function of $x$, $a_i(x)$. I would like to know what is the most efficient way to ...
-1
votes
2answers
491 views

A simple ListPlot with different colours and a Tooltip

I know that the threads ListPlot with each point a different color and a legend bar and Extracting the coordinate of a particular point of interest from a ListPlot are somehow the answers to my ...
2
votes
1answer
125 views

how to set initial conditions when solving recursive equation with tables

I am solving a recursive expression with ParallelTable. Here is a MWE showing how I do it, and how I set the initial condition: ...
1
vote
0answers
45 views

Using anonymous functions instead of module or block. Bad idea? [duplicate]

Here is an example function which returns True if a point p is on an (open) line segment (A, B) assuming that Orientation[A, p, B] returns 0 if the three points are collinear: ...
4
votes
3answers
605 views

Inverting a Spline-Function (Bezier or BSpline)

I would like to use a Spline-Function to describe a transformation from one range of reals to another, that is I would like to have a function which maps a value $y$ on $x$ and for simplicity let us ...
8
votes
2answers
219 views

Distribute and analyze large datasets

I need to analyze very large datasets, and they obviously don't fit in a computer memory. I need to produce some statistics on these datasets, and this brings me here: How can I make some statistical ...
5
votes
1answer
174 views

Default FontFamily for PlotLabel

This is probably a rather basic question and I presume I am simply unable to make proper use of the Options[] function: I am trying to figure out what the default ...
0
votes
1answer
228 views

Constraining solution's sign with NSolve

I am solving some equations in 4 variables, however, there are many solutions which are basically the same but changing relative signs of each other ... i.e. {x->-1,y->1} and {x->1,y->-1}. ...
6
votes
2answers
401 views

How to open hyperlinks (from web-embedded CDF) in a new tab

I have a problem with Hyperlink (in a web-embedded CDF) opening links in the same browser tab and I couldn't find an option to avoid that. I have the following ...
1
vote
3answers
425 views

How can i get the solution of complicated equation?

This is the equation about zeta. NSolve[eq] could not solve this equation. (I think it is too complex to solve by NSolve.) I ...
8
votes
3answers
2k views

“Save Graphic As…” does not include plot legends

I am creating some plots with Show but unfortunately the PlotLegends seems to be out of the bounding box when saving the graph. ...
11
votes
4answers
10k views

Finding all simple paths between two vertices in a graph

There are built-in methods to find a shortest path between two vertices in a graph, and the question on finding all shortest paths between two vertices has gathered quite a bit of attention. A path ...
3
votes
1answer
155 views

How can I set multiple values to local variables in a Module?

Multiple assignment is supported by Set. How can do something similar in Module expressions? If I could do it, whould there be ...
7
votes
2answers
690 views
23
votes
1answer
224 views

What does Internal`InheritedBlock do?

What does the function Internal`InheritedBlock do? How is it different from the regular Block?
3
votes
2answers
103 views

How to apply multiple/complicated requirements for a pattern in a function input [duplicate]

In this question. I suggested that to test whether the input of a function was a matrix of numbers one could create the following test: ...
0
votes
1answer
217 views

Projection of a set of 4D points to the 3D space

Consider the following set of points in the 4D space: ...
7
votes
4answers
334 views

Counting multiplications (complexity function)

I'm trying to count the number of times multiplication appears in an expression (for the purpose of constructing a ComplexityFunction that would help me simplify a terrible algebraic expression for ...
24
votes
7answers
2k views

Embed Code Into Image

I often export images(plots, matrix, arrays, etc..) from mathematica which I end up putting in word documents or uploading to the web. The problem is that I often lose the original code and I am left ...
1
vote
0answers
74 views

Is the TCPIP link type compressed?

Since I'm already piping a MathLink connection in a ssh tunnel (connect back is a pain!), I wonder if it makes sense to compress the data in the stream (ssh -C). As ...
2
votes
1answer
172 views

Explicit asterisk or @ sign in string patterns

What string pattern will match an explicit asterisk (*) or at-sign (@)? The obvious example, StringMatchQ["*", "\*"], returns ...
2
votes
2answers
186 views

Finding integral points on a surface

Suppose I have a dimension formula (for a Lie algebra representation) that is as follows: $$ d(a,b) = {(a+1)(b+1)(a+b+2) \over 2} $$ Now consider the surface $F(a,b,n) = 0 = d(a,b) -n$ where $n \in ...
2
votes
2answers
285 views

Mapping multiple functions

This question was part of a course on Mathematica written in 1998. Each of the functions f1, f2, and f3 defined below has a root near x=2. Map an anonymous function involving FindRoot[] onto ...
1
vote
0answers
59 views

Sorting Eigensystems [duplicate]

SO I have this code: ...
11
votes
3answers
701 views

Every second evaluation in notebook front end is slow

I'm having a rather baffling problem that Wolfram was unable to help me diagnose, and I'm hoping one of you geniuses in residence here can figure it out. (I don't get access to the Technical Support ...
1
vote
3answers
306 views

Making a calculation with high precision

I would like to make the following calculation: 1/Sqrt[1 - (150^2 10^(-4))/(9 10^16.)] - 1 Mathematica 8 returns 0. The result is obviously not 0, but my ...
6
votes
2answers
251 views

Is it possible to import data from Google Analytics?

Using Mathematica, is it possible to pull data directly from Google Analytics? Unfortunately, GA exports messy csv files, and I was wondering if there was a direct ...
2
votes
2answers
665 views

Forecast Future Stock Prices - Brownian Motion - Again

excuse me, I think I have here a technical problem with Mathematica yesterday I posted the question with the title: Forecast Future Stock Prices - Brownian Motion I am still not very experienced but ...
4
votes
1answer
184 views

String encoding issue with Pythonika

I use Mathematica and Pythonika to run Python code inside it. And I'm not quite sure what causes my issue: all unicode Python objects look like this: ...
3
votes
1answer
83 views

Some _atomic elements' TreeForm looks confusing with Level in appearance

In[1]:= Level[1/2,{-1}] Out[1]= {1/2} TreeForm[1/2] ...
3
votes
3answers
196 views

Plot sublists as different colors

I have one big list with many sublists inside. All sublists consist of three numbers. For example: ...
2
votes
1answer
54 views

Does a manipulation of a plot area produce new data?

You do a ListPlot. Plot[Sin[x^2], {x, 0, 1}] pdat1 = With[{fig = Plot[Sin[x^2], {x, 0, 1}]}, First@Cases[fig, Line[x_] :> x, Infinity]]; You ...
3
votes
1answer
186 views

How to extend dictionary.txt

How to extend the default dictionary.txt for Dictionarylookup to all words? For example, first I ...
4
votes
1answer
384 views

ListContourPlot is blocking my geometry

I have a Navier-Stokes solution for a flow past a cylinder. I have attached the DAT file. The columns in the DAT file contain the x,y,u,v,p data, respectively. The DAT file can be obtained from our ...
7
votes
2answers
861 views
17
votes
3answers
285 views

Options which require RuleDelayed

For some functions in Mathematica it is important to use RuleDelayed. One prominent example is the EvaluationMonitor for ...
39
votes
9answers
4k views

Having used Mathematica as a “gateway” language, where to from here?

I have been using Mathematica for about a year. It is the first language that I have attempted to learn. I'm still very much a newbie, but there are moments I feel more like I am waving than drowning. ...
6
votes
3answers
179 views

Is it possible to Import urls not type “”

These days I often copy urls from Internet Explorer's address bar. When I paste the url into a Mathematica cell it is neither a string nor a expression. ...
1
vote
0answers
60 views

Abridging Lists of Equations within NDSolve, Manipulate [duplicate]

I have a pretty little NDSolve function that I've finally decked out with manipulatable (by sliders) coefficients, which changes the graph in real time. However, I ...

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