0
votes
0answers
3 views

Kernel quits without error in NDSolveValue

I am using the latest 10.1. The following single line command makes the kernel quit without error message (just a beep): NDSolveValue[{- !(*SuperscriptBox[([CapitalPhi]), TagBox[ RowBox[{"(", ...
0
votes
0answers
8 views

First Order Conditions

I am new to Mathematica so I am not sure if this is correct. I have setup up a Lagrangian and I am trying to get the FOCs of this problem. However, it does not seem to work. Any help would be much ...
0
votes
1answer
14 views
3
votes
0answers
14 views

MoonPosition and TimeZone support

With this question, I noticed some some weird results of MoonPosition. Consider the following code: ...
0
votes
0answers
11 views

Find first n roots of a function

Is there a straightforward way to find the first $n$ roots of a function? I have found various ways of finding roots in an interval, but none that would keep looking for roots until they find a ...
14
votes
1answer
420 views

What is the real default CellEvaluationFunction?

The default CellEvaluationFunction is Identity but one can quickly see that this is handled specially as an equivalent function, ...
4
votes
0answers
33 views

Wrong autogenerated package from notebook containing #key and Part as subscript

Mathematica v10.1.0, under Windows 8.1 x64 Mathematica v10.0.2, under Windows 1) Define a function in an initialization cell: ...
0
votes
0answers
30 views

Why Mathematica doesn't solve this equation?

I look for solve my geometry problem. To do this, I need get formula for "d" in my equation: ...
16
votes
1answer
151 views

No analogue for Maple's dchange?

Maple owns an interesting function called dchange which can change the variables of differential equations, but there seems to be no such function in Mathematica. ...
-1
votes
1answer
76 views
0
votes
1answer
18 views

Change numerical plot labels on one axis to strings

This question likely has a straightforward answer. Suppose I have a plot something like this: ...
0
votes
1answer
22 views

using output in pure function

Suppose i have an integral which has a close form, $\int_{a}^{b} f(x) dx=F(a,b)$ I want to use output function $F$ as a pure function, like F[a,#]& so i try ...
1
vote
1answer
98 views

Control which frontend session/kernel the Workbench gets attached to

(I am new to Workbench) I have 2 or 3 Mathematica frontend sessions open with a few of them running some long-running codes. When I try to open/edit a code in Workbench, I see that it sometimes it ...
1
vote
1answer
26 views

Generating by plots by rerunning code

I am new to Mathematica. I created a code where I can evaluate a parameter (denoted by PoA) for a random instance of a directed acyclic graph. The code is below. ...
-1
votes
1answer
25 views

interpreting wave equation using mathematica

hi can someone please help me solving this problem: Let $u(x, t)$ be a solution of a wave equation $u_{tt} − u_{xx} = 0$, $x \in (0, 2\pi)$, $t > 0$ satisfying Neumann boundary conditions $u_x(0, ...
0
votes
0answers
13 views

power series or taylor series for transcendental equation [on hold]

Can anyone please show me how to find a power series or taylor series for $p(h)$, an implicit function of $h$ implied by the following equation: $-plog(p) - (1-p)log(\frac{1-p}{n-1}) - h = 0$ ?? ...
-2
votes
0answers
19 views

Maximize Duplicate digits Equation

Let's save I have a simple equation like the following. P(1+r/n)^(n*t) How might I most simply maximize the number of duplicate digits in the equation?
1
vote
0answers
19 views
0
votes
1answer
28 views

Improving Performance - Finding Polynomial Roots

I'm fairly new to Mathematica. In the past, my usage has mostly been limited to solving the occasional equation, making some plots, and working with small scaled statistics. None of these have been ...
3
votes
1answer
64 views

compute the gradient in high dimension

The following code is used to compute the gradient of a given 2D data. ...
11
votes
4answers
482 views

Finding the period of an array of integers

A simple array of integers is given. The problem is to detect if a pattern is repeatedly occurring in the array, and find the length of that pattern. For example, for ...
0
votes
1answer
131 views

Making table and plotting results of NDSolve problem

I am trying to solve two equation to find /[Phi][x] and plot h vs. /[Phi][x] for different values of L.I tried by writing as: ...
1
vote
2answers
142 views

Extract data from DateListPlot, limited by PlotRange

Extracting the points from a line in a ListPlot in this answer uses points = Cases[Normal@plot, Line[pts_] :> pts, Infinity]; This works in DateListPlot ...
6
votes
2answers
1k views

How to make traditional output for derivatives

Hello again after some pause. i have a problem how to present partial derivatives in traditional form, not as Mathematica gave it to me in its notation. So I want to present this ...
18
votes
2answers
9k views

How to make Jacobian automatically in Mathematica

If we have two vectors, a and b, how can I make Jacobian matrix automatically in Mathematica? $$ a=\left( \begin{array}{c} \text{x1}^3+2\text{x2}^2 \\ 3\text{x1}^4+7\text{x2} \end{array} ...
1
vote
1answer
24 views

Partial derivative of defined function with vector input

Background: Have written a formula for the refractive index for a glass slab (n) that depends on the variables t,a and d. Now I want to calculate for example some sort of error and I'll be needing to ...
1
vote
1answer
54 views

NonlinearModelFit: fit a vector-valued function to a data vector

I have a vector of data points: data = 10 Sin[#/10] + RandomVariate@NormalDistribution[] & /@ Range[200]; And I have model that provides the complete ...
2
votes
1answer
54 views

Abstract iterator in Do

I'm trying to write a module. Its input is a matrix (tensor), the module should return new tensor with increased rank with 1. The new tensor is defined as $$ O \Rightarrow N_{\alpha \beta \ldots ...
1
vote
3answers
98 views

Import Data using selection criteria

I imported a file (text and numbers) and made constructed this. e[[1,All,{1,2,3,4,6}]] Column 1 is the name of the state. How can I get a subset of this where, say Column 1 is not equal to "New ...
3
votes
0answers
27 views

DateObject for current date skips a day when crossing the date line with TimeZone

The DateObject was introduced in version 10 of Mathematica. One can call it to fetch the current local date and time: ...
3
votes
2answers
50 views

How to re-arrange lists, divide one list into 2 lists with a particular step [duplicate]

How to re-arrange following list: {a1,b1,a2,b2,a3,b3,a4,b4} or this {a1,b1},{a2,b2},{a3,b3},{a4,b4} to get: ...
1
vote
1answer
45 views

What is the correct idiom for mapping a 0 value in a modulo n expression back to n?

What is the correct idiom for mapping the $0$ value in a modulo $n$ expression back to $n$. For example if I want to be sure that any integer value maps back to the index for a character in the ...
0
votes
0answers
39 views

What does it mean when FindInstance returns unevaluated?

According to the documentation, FindInstance[] return the empty set when it does not find a solution and one of the examples claims that this is proof that no solution exists. So if FindInstance[] ...
1
vote
1answer
105 views

how to create Panel for Plot?

Can You advice me how to put the whole thing below into an interactive Panel, so I can values of parameters dynamically - type other values (alpha, beta, x0, y0, R, tmax) and plot updates ...
8
votes
0answers
205 views

Getting EPS imports to respect the original fill rule

One major problem in my attempt to answer to the CountryData flags question is that the way Mathematica handles filled curves differs from the way SVG and EPS style editors do. The latter two have the ...
32
votes
3answers
2k views

How to do http POST in Mathematica?

The Import command lets you do a HTTP GET from a URL, like this Import @ "http://merkosoncampus.com/wp-content/uploads/2011/05/higgs-boson.jpg" This sends an ...
5
votes
2answers
137 views

Nearest neighbor distribution

I need to construct nearest neighbor distribution for a given finite set of real numbers. I have no clue how this can be realized. Any suggestion would be very much appreciated.
6
votes
1answer
50 views

Using Wolfram Library Reference in Excel VBA

Long time ago I did this question to MathGroup, but without success. In Excel VBA, in Tool/References, there is a option called "Wolfram Mathematica Control 8.0 Type Library" I belive that ...
27
votes
2answers
2k views

An efficient circular arc primitive for Graphics3D

As many people have noted, the 2D graphics primitive Circle doesn't work in a Graphics3D environment. Several solutions to this ...
4
votes
1answer
237 views

ArrayPlot copied to PDF shows blurred mesh

Certain (but not all) images displayed in ArrayPlot, and then copied to PDF, show what appear to be fuzzy mesh lines in white areas. An example is shown below. I ...
12
votes
3answers
484 views

Next highly composite number?

R language has this function 'nextn' (link) which computes the next highly composite number greater than a given one, which is used to find the optimal padding size for the subsequent FFT operation. ...
8
votes
1answer
97 views

How to access an already opened Excel file in Mathematica?

This post 4594 shows how to open a existent Excel file with Mathematica. And this 6686886 shows how to do what I need, but in C#. This 12282310 is another related one. How can I connect to a ...
0
votes
0answers
48 views

How to make work Plus function? [duplicate]

I have a little problem. I have k = 1.56343*10^9; r = 9.10492*10^18. And I should receive a (2*r*r-k*k)/2*r*r, it equals to ...
0
votes
0answers
35 views

Nest-Recursion leads to overflow - Numerical calculation of Lyapunov exponents [on hold]

I calculate the Lyapunov exponents of several dynamical systems and want to compare the results with other algorithms. One of the most famous puplications is the work of Marco Sandri, see this paper. ...
-2
votes
0answers
50 views

How speed the calculatation of the inverse of an upper triangular matrix

I have found the inverse of an upper triangular matrix by substitution using the "for" command, but it works very slowly when the upper triangular matrix is big. Example: If 686 is matrix's ...
10
votes
1answer
572 views

Problems with “Test Connectivity” and the Pacletserver

I know there has been a similar questions to this already but the solution did not work for me so here again: I have internet connection and I can execute such commands like: ...
1
vote
0answers
33 views

Faster trimming of leading/trailing zeroes in rectangular array

Given a (large) rectangular array, e.g. (small for example case): ...
6
votes
2answers
74 views

why MeanFilter is nearly 100 times slower than MovingAverage for 1D array?

I used to average over my data with MeanFilter before I learn about MovingAverage and thought that these two functions are similar except that MeanFilter is more powerful for its ability to deal with ...
0
votes
2answers
53 views

Use a Module to return multiple plots

A program I'm running requires me to generate multiple plots over the same domain, so I thought it would be fairly simple to use a module and bury all of the plot commands within that that way I only ...

15 30 50 per page