All Questions

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: ...
459 views

Finding Points of Tangency of a Circle and a Parametric Curve

I have the following Parametric plot Generated from the following: ...
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 ...
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: ...
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 ...
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 ...
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 ...
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 ...
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 ...
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) ...
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: ...
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 ...
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. ...
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 ...
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 ...
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 ...
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 ...
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 ...
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: ...
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 ...
70 views

I'm figuring how to implement a function behavior based on the Head of its argument. I mean ...
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 ...
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: ...
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 ...
434 views

FindFit (Jacobian Error) [duplicate]

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

I have this: ...
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 ...
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. ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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?
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 ...
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 ...
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 ...
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 ...
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. ...
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 ...
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 ...
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 ...
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 ...
297 views

Data Table Manipulation

Suppose that I have the following ...
91 views

SQL Queries with the Table function

Given the following connection to an SQL query works but the data comes out wrong: ...
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 ...
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 ...