1
vote
1answer
103 views

Empty plot - Euler's method

The answer from this question helped me use Euler's method. It worked for a simple function, but when the function is more complicated, I get an empty plot. This is my function: ...
5
votes
2answers
459 views

Finding Points of Tangency of a Circle and a Parametric Curve

I have the following Parametric plot Generated from the following: ...
1
vote
1answer
80 views

Forcing contours to close at edge

I have some data that I am plotting with ListContourPlot and I would like my contours to be closed at the edge (closing around the high value region). A simple ...
0
votes
1answer
239 views

Numerical Methods - minimum of a function

Problem: The length of the longest ladder that can negotiate the corner depicted in Figure 2 can be determined by computing the value of theta that minimizes the following function: ...
3
votes
0answers
136 views

Automatically Recording Sound

I was hoping I could recreate a noise cancelling set-up by recording sound from the microphone in my headset or from the computer and play it back in my speakers or headphones with the appropriate ...
0
votes
1answer
112 views

How to save numbers that are in Mathematica messages

I have a program that calls FindDistributionParameters and I get the Mathematica message FindMaximum::eit each time I call the function. The message is FindMaximum::eit: The algorithm does not ...
1
vote
1answer
113 views

Change Ticks in PairedBarChart

I am using the PairedBarChart feature as follows: PairedBarChart[Range[5], Range[5], BarOrigin -> "XAxis"] How can I (i) remove and (ii) change the number ...
2
votes
2answers
79 views

Can I have Mathematica show intermediate forms before final evaluation?

If I have x = 2 and I want to evaluate y = x^2 I would like to the output to show ...
0
votes
1answer
370 views

logplot for negative valued function

I would like to plot the following function Plot[(1/x (0.01/(0.01 + x^2) - (10/(10 + x^2))^2)), {x, 0, 10}, Frame -> True, PlotRange -> All] which is ...
4
votes
4answers
380 views

Efficient method for Inserting arrays into arrays

This is strongly related to the following Questions: Looking for a way to insert multiple elements into multiple positions simultaneously in a list Building matrices by attaching vectors (columns) ...
2
votes
1answer
70 views

Matching a list of sequences with common form

I am trying to find a pattern that matches a list of sequences that share a common form. The sequence form is: 1 followed by zero or more nonzero integers, followed by 0. An example list is: ...
1
vote
0answers
111 views

What is the fastest way to obtain the eigenvalues of a Wishart matrix?

I would like a fast method of creating a sample of random numbers which corresponds to the eigenvalues of a Wishart matrix: For M>N the eigenvalues \lambda_i are given by the jpd Where $K_N$ is ...
0
votes
1answer
204 views

Series expansion of a complex function

How do I expand a function $f(z)$ in a particular region? For example, how would I expand $f(z)=(z^2-3z+2)^{-1}$ in the region $0<|z-1|<1.$? I believe this can be done by the binomial theorem. ...
1
vote
2answers
114 views

How to switch between a binary number as String and a as a list of digits?

I was trying with String Functions and I viewing any posts and have no results I want to know 1.- From cromo33 = Table[RandomInteger[], {i, 1, 33}] cromo33 ...
1
vote
0answers
53 views

How to change default font? [duplicate]

Sometimes even I change the text font from arial to courier new, when a new formula cell is created, things inside become arial again. How to tackle this problem? Furthermore, is it possible to change ...
1
vote
3answers
374 views

Plot with plot markers without using ListPlot

I would like to plot a continuous function with Plot with plot markers as if it were a ListPlot plot. Simple example: I have ...
2
votes
1answer
147 views

Getting cdf content from nice Wolfram info graphic

There is a very nice cdf info graphic on the Wolfram Webpage (http://www.wolfram.com/cdf/uses-examples/infographics-full-example.html). I'd like to have a look at the code as I'd like to do something ...
0
votes
2answers
134 views

The precision of the number

I have problem in Mathematica with unnecessary rounding which is caused by high precision. For example I have value a = 2.052685846*10^-1865, when I make ...
2
votes
1answer
93 views

Why there is no SlotSequence (##) form analogical to #[[ ;; n]]

I'm aware that this may be closed as offtopic but there are people around with "offtopic" knowledge :) So, in List context we can: ...
1
vote
0answers
127 views

How to make Layer Directed Graphs (LDG) in mathematica?

I am wondering if I can make a graph like that somehow: I am new to mathematica, I tried to play with Creating a graph with variable size of vertices and variable thickness of edges . I figured if I ...
1
vote
0answers
70 views

Function behavior based on Head

I'm figuring how to implement a function behavior based on the Head of its argument. I mean ...
6
votes
6answers
661 views

Choosing $n$ equidistant points on a circle with given radius and center

I would like to have a function circle which takes two inputs: a tuple {x,y} and a real number ...
3
votes
2answers
287 views

Mapping multiple functions over an array

I am looking for an elegant way to Map multiple functions over an array. My problem looks something like this: Consider a list of functions: ...
4
votes
0answers
115 views

“Off-label use” of Mathematica functions for performance

Assisting an acquaintance with a simulation where a very large number of binomial probability calculations are required, I pointed them to a slightly obscure function to dramatically speed up their ...
1
vote
1answer
434 views

FindFit (Jacobian Error) [duplicate]

I, like others before me, am struggling with FindFit. So, I tried a simple example. ...
0
votes
0answers
54 views

Since when is a log distributed across a finite sum?

I have this: ...
1
vote
2answers
144 views

A possible error related to the evaluation of a double integral

According to the Mathematica, the integral below NIntegrate[ Log[Log[1/(x y )]] Log[1/(x y )]^(-0.5 - 1), {x, 0, 1}, {y, 0,1}] might possibly evaluate to ...
0
votes
0answers
262 views

Boundary Value Problem- using NDSolve or another method

I am trying to solve a set of coupled partial differential equations, with defined boundary conditions using mathematica. Here are the equations and the boundary conditions. ...
1
vote
2answers
116 views

Functions of two arguments

I am pretty weak on the notion of pure functions, etc. I found a clean solution to my problem so in a sense I've already answered my own question but I don't feel I'm on terra firma. I wanted to take ...
5
votes
2answers
181 views

Entering scientific notation in an InputField

I am trying to make an InputField for numeric input, but InputField[Dynamic[num],Number] Does not allow the user to type ...
0
votes
1answer
193 views

Issue with Compile

The following code works fine with the the function f defined as a module, however, when I convert it to be a compiled function, it gives me errors. Can some one ...
0
votes
2answers
162 views

Summarizing SQL Tables

data = Table[SQLSelect[conn, "All", {"col1", "col2"}, SQLColumn["col1"] == n && SQLColumn["col2"] == o], {n, 1, 8}, {o, 21, 30}]; This results in ...
0
votes
2answers
141 views

Fill below two functions.

I'm new to Mathematica and some of the filling stuff is confusing me. I don't think this should be too hard but I can't seem to get it to work. I have plotted x and -x. I want to fill below BOTH of ...
1
vote
1answer
158 views

How to calculate the following integral of the multiplication of two Bessel functions?

This integration has an analytical solution and its behavior is described by 1/r^2 function, but Mathematica gives some weird oscillating answer. Can anybody explain this and help me overcome this ...
0
votes
1answer
85 views

What is the meaning of Automatic in goodness of fit test?

I can't find what is the distribution corresponding to the default option in: DistributionFitTest[data, Automatic, "HypothesisTestData"]; Is it N(0,1), uniform?
2
votes
2answers
264 views

WhenEvent for several variables

I want to solve a system of nonlinear two differential equations (say, in $\theta(x,t)$ and $\phi(x,t)$ with NDSolve, but I want to stop the evaluation when one of ...
0
votes
2answers
122 views

Setting CheckboxBar defaults under Manipulate

How is the default for the checkboxes created by CheckboxBar in a Manipulate set to be checked instead of unchecked? (The ...
1
vote
2answers
134 views

Error Trapping Complex Infinity Error due to Divide by Zero in Manipulate

I want to use a Manipulate that has two controllers that end up as a difference in the denominator of an expression. It is easy enough to set up the initial ...
1
vote
1answer
78 views

Moving the start of a graph to the right, finding maxima in an oscillator

I have the following code written to simulate a driven damped oscillator ...
0
votes
1answer
79 views

How to compile gather [duplicate]

First question,How to Compile this? gather[data_]:=Gather[data, Mod[#1, 3] == Mod[#2, 3] &] I dont know why this is wrong. ...
0
votes
1answer
417 views

Trying to solve a transcendental equation involving Bessel functions

I've never used Mathematica before and am trying to numerically solve equation (12) from this paper. Ideally I'd be able to find the smallest value of $x_{n\nu}$ for $\exp(-kr\pi)$ close to 1, and ...
19
votes
2answers
732 views

How to make a curve selectable from a scaned image and convert it to a list of coordinates

I have a scanned image (binary-ized): Is there any way to reduce one of these curved lines (full or dotted) to a series of its coordinates (e.g., sampling interval of 0.01 on x-axis)? I've read ...
2
votes
2answers
187 views

Set PointSize to pixel size

I have a set of 1million 2D points and I would like to produce an image 200x200 pixels where each point will have the size of a pixel (no more). Additionally each point may repeats several times so I ...
4
votes
1answer
163 views

What are the hidden specifications for FindRoot

The Help page of FindRoot says: "by default, FindRoot uses Newton's method (Newton-Raphson) to solve a nonlinear system" (or a nonlinear equation I ...
3
votes
3answers
297 views

Data Table Manipulation

Suppose that I have the following ...
2
votes
1answer
91 views

SQL Queries with the Table function

Given the following connection to an SQL query works but the data comes out wrong: ...
3
votes
3answers
199 views

FindRoot constrained to maximum

I am using FindRoot to find the local maximum op some function, by examining where its derivative is zero. However, keeping the starting value the same, sometimes ...
2
votes
1answer
111 views

Accessing Draw Tools objects with notebook commands

In a notebook I would like to be able to access and modify the properties of draw tools objects after I've drawn them on a graph by hand. For example, if make a plot and, with draw tools, make a ...
0
votes
0answers
16 views

?AspectRatio? setting to obtain equal length pr pixel on all axes [duplicate]

Like these does: Show[Graphics[Rectangle[{2, 1}, {15, 2}]]] ParametricPlot[{t,t t},{t,0,2}] how do I create a Plot[] with ...
1
vote
0answers
74 views

Mathematica exit when calling plot. Bug?

I'm currently studing the behaviour of some integral for which I cant find an analytic solution. As this function depend on a vector on the unit sphere, I first defined it with 3 parameters before ...

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