All Questions

376 views

Returning a value from a Module

In the following simple example MyMod := Module[{i}, Do[ Return[1], {i, 3} ]; Print["test"] ] I expected the module to exit on ...
127 views

NDSolve in exact points - nonlinear equation (Degrees and Radians confusion)

I found solutions of two nonlinear equations, but I have three small questions. First I am in confusion because of initial value. The system is mechanical and unknown ϕ is an angle, which I set to ...
70 views

Is It Possible To Replicate Tab Stop Behaviour (or Even PageFooter Behaviour but in Regular Cell)

I am trying to insert a (text) cell into a notebook that replicates the behaviour of tab stops in MS Word, for example. Put differently, I have two strings and I want the one string to align on the ...
216 views

Sample of the random times at which the random walk crosses the boundary

I defined a security boundary for a random walk: ...
104 views

nonlinearnodelfit with a matrix as weights

I have to fit a non linear model to my data and I am trying to use nonlinearmodelfit. The problem is that I have systematic errors, so the ...
714 views

Alternating sum

A frog is at the bottom of a 30 metre well. Each day it climbs 5 metres up the side, but it then slips back 3 metres each night. How long does it take to reach the top of the well? Is there an easier ...
460 views

Exporting EPS figures with dashing from ListPlot

I am having difficulties exporting EPS figures. If I use the LineLegend option to create a dashed or a dot-dashed line, it seems ok in Mathematica 9.0 e.g.: But the problem came out when the ...
91 views

How to get diagonal matrix D from matrix multiplication of $s^{-1}$, P, and S

I am multiplying three matrices that should give me a diagonal matrix but instead of zeros for the other entries I get very small numbers. Can someone explain what is going on here and how I can fix ...
354 views

Base 2 Tick Labels for ListLogLogPlot

I am using ListLogLogPlot and would like to express the x-axis tick labels in powers of 2 instead of the default powers of 10. Does anybody have experience with ...
180 views

66 views

How to avoid malicious code when opening & executing notebooks [duplicate]

Is there any way to avoid malicious code when opening and executing entire notebooks automatically? I have written code which opens a large series of notebooks one-by-one, evaluates them in their ...
111 views

How do I produce iterative equations and bifurcation diagrams?

I need to produce orbit diagrams for different values of x for the following equation: f[r_][x_]:= r*x - x^3 I'm fairly new to Mathematica, so I haven't had a ...
534 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 ...
129 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: ...
855 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 ...
702 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. ...
161 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 ...
112 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 ...
650 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 ...
280 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 ...
103 views

Evaluate integral of a series

I want to evaluate this integral, but it won't work. Does anyone knows why? ...
175 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 = ...
141 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 ...
189 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 ...
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 ...
369 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: ...
110 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: ...