# All Questions

507 views

### Is it possible to suppress 'Out[xxx]=' without suppressing 'In[xxx]:='?

While I have not exhaustively searched Help/Documentation Center for an answer to my question, I have put forth a yeoman's effort without any success. Does anyone ...
118 views

### Problem with numerical integration

I am not very used to do numerical simulations on Mathematica. I have a problem with numerical integration of this function. Is there any way for this calculation? Input: ...
798 views

### Random walk on a sphere [closed]

I'm trying to programme a random walk on a sphere with Mathematica. I found this code while I was searching, but I'm not getting results from it. I waited an entire day, but my pc didn't finish ...
670 views

### Time derivative of unit vector in spherical coordinates

Is it possible to take a time derivative of a vector given in some curvelinear coordinate system (i.e. spherical)? Mathematica would need to take into account the time dependence of the basis vectors. ...
89 views

### A question about using Reduce [closed]

Can someone help decipher what is the meaning of this computation that Mathematica has done? ...
144 views

### About making a fraction “taller” [duplicate]

I encountered 2 problema with displaying formula in text format. The variables in the formula is italic, I want to change them to normal. And the fraction size is too small, I want to make it to ...
101 views

### Solutions of cubic equation D>0 or D<0

I have problem to obtain three roots of cubic equation N[Solve[a x^3 + b*x^2 + c*x + d == 0, x], 15] using analytical procedure ...
547 views

### Map of Specific US States? (Isolated)

My question here is fairly basic, and I'm sure I'm overlooking something basic. I know about CountryData for creating shapes of entire countries, and it works, to ...
230 views

### Factor a Vector

Does there exist a function in Mathematica that simply takes out a common factor from a vector/list of expressions? This seems like such a simple operation that I am surprised that I could not find it ...
102 views

### Evaluate integral of a series

I want to evaluate this integral, but it won't work. Does anyone knows why? ...
166 views

### Eigenvector Anomaly

I'm trying to compute the eigenvectors for: $$M = \left( \begin{array}{ccc} 1 & 4 \\ 4 & 100 \end{array} \right)$$ Both myself and Mathematica report the eigenvalues as:  \lambda_1 = ...
136 views

### Numerically solving an ODE for a parameter

My equation is as follows: sol = ParametricNDSolve[{(f'[r]^2 - 1) f'[r] r == 6.2 (f'[1])^2/1000, f[1] == a}, {f}, {r, 1, 3}, {a}] where the function ...
173 views

### Intersection of any triangle with a circle in Cartesian coordinates

I started a notebook dealing with metrics in a triangle and its intersection points by a circle. Up to know I reached the point of having plotted a triangle, a circle with an arbitrary centre and I ...
96 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: ...
409 views

### Intersection of Osculating Circle with a Parametric Curve

I have the following Parametric plot Generated from the following: ...
76 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 ...
195 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: ...
107 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 ...
102 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 ...
104 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 ...
77 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 ...
302 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 ...
368 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) ...
53 views

### What's wrong with this stylesheet? [closed]

I edited this style sheet: ...
68 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: ...
268 views

### How to import and visualize a network stored as an edge list in CSV file? [closed]

I'm extremely new to Mathematica, and I'm trying to import an edgelist representing a network, but I think I'm missing something major. Here is my process so far just to import and visualize the ...
103 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 ...
174 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. ...
99 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 ...
47 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 ...
329 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 ...
137 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 ...
130 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 ...
86 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: ...
122 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 ...
66 views

### Function behavior based on Head

I'm figuring how to implement a function behavior based on the Head of its argument. I mean ...
541 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 ...
271 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: ...
110 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 ...
335 views

### FindFit (Jacobian Error) [duplicate]

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

I have this: ...
120 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 ...
212 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. ...
112 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 ...
164 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 ...
174 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 ...
158 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 ...
118 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 ...