# All Questions

92 views

### How to do this triple integral?

I have a triple integral which is kind of complex, and I want to use Mathematics to help me do the integral. However, when I press "Enter" and "Shift" the software get stuck. I wonder whether this ...
35 views

### How can I change this function for the better? [duplicate]

I have a function for an lfsr (linear feedback shift register): ...
60 views

### How can I construct a random graph, which is created by adding orientation to a complete graph?

Given a complete graph on N vertices, how can I randomly orient all of its edges? I thought about starting out with CompleteGraph[n], and then somehow transforming ...
65 views

### How can I compare two iteration results and define error?

I have code for Muller's method, I used command While. At the end I have to compare iteration result with previous iteration result and define error. I can write this condition: ...
131 views

### Implicit differentiation and the Folium of Descartes [duplicate]

Given the function (Folium of Descartes) $x^3 + y^3 = 3xy$, how would I find the equations for tangent and normal lines at the point $\left( \frac{3}{2},\frac{3}{2} \right)$? I know that I must use ...
171 views

### Straightforward way to make a multicolumn line legend?

I have a plot showing 8 curves, and I'm able to define a line legend styled in either a column or a row version. I have the following code: ...
65 views

### Program hidden beneath an interface in mathematica [duplicate]

I recently wrote a mathematica code that I would like to distribute to some friends. However, I don't want to give away the code. Is there a way that I can hide the code beneath an interface kind of ...
110 views

### Reflecting lines in ellipses: speed up the code?

I have the following code which calculates a list of points that a line would take after bouncing off various ellipses. ...
57 views

### Function to find minimum element in array [duplicate]

i have this code: ...
106 views

### plot sum of two function

I am trying to illustrate sum of functions. I have one function x*x - 8*x + 7 and another Log[2*x + 4.5] I understand that I ...
200 views

### mixing color of individual parts of a function in DensityPlot

I have a function which is a sum of three terms and I want to plot it in a DensityPlot. However, I would like that the ColorFunction would be the RGBColor resulting of the mixed R color corresponding ...
93 views

### Find maximum of 'y' coordinates from a list of duplicate 'x' coordinates

I have a multidimensional-variable list, suppose for example {{x1,y1},{x2,y2}..}. I have duplicate values for the 'x' coordinates and I need to find for the duplicate 'x' elements the corresponding ...
98 views

I currently use MapThread[f, {{a1, a2}, {b1, b2}] for obtaining { f[a1, b1], f[a2, b2] }. Is there a version (or alternative) ...
136 views

### Finding uniformly distributed random points on an ellipsoid

I am trying to generate a poincare map for a system whose reduced energy manifold looks like the following surface. (x/a)^2 +(y/b)^2 +(z/c)^2=1 I want to find a ...
133 views

### Exporting pdf with a precise page dimension in metric units, rather than printer points

Mathematica uses a screen resolution of 72 dpi. For post-processing figures I use Corel, which conveniently allows me to use metric units (mm) for positioning and resizing figures. Say, I want to ...
63 views

### Can I name a variable as D(1,0,+1/2)? [closed]

I am trying to use variables with names as D(0,0,0), D(1,1/2,+1/2), etc. but I don't know how to do it.
127 views

### Paired Bar Chart with negative values

Dear Mathematica group I want to plot negative values using PairedBarChart in V9 However, with this code ...
97 views

### Phase Portrait Trajectories

How do I make a phase portrait which looks like the ones demonnstrated here? Not the fancy version where I can use the controls to change it, just a screen-shotted version of say a spiral point? Any ...
89 views

### 3D Plot for Attractive and Repuslive Field Functions [closed]

I am using Mathematica to plot the total potentials (which is the sum of an attractive potential field and a repulsive potential field) - This is related the Artificial Potential Field Method in ...
153 views

### How to put triangle graphics on a plot of two seperate related lists?

For 7 different discharge energies, I have two gases (1. pure helium, 2. a helium oxygen mixture) being heated up. Those 14 settings then enter a tube, in which the system cools off. In the list ...
169 views

### How to rewrite the rules in a list when they satisfy a given condition

I think the best way to state my problem is to illustrate it with an example. Assume I have the following toy-list of rules: ...
205 views

### Built in function without Attributes Listable works as if it has Attributes Listable

Can Built-in function works as if it has Attributes Listable even if it doesn't have that ...
58 views

### How to access data from WHO Mortality Database

How to do I access the online data from the WHO Mortality Database, which is free to download. What are the Mathematica specific commands to directly load the xls file that can be obtained from this ...
119 views

### GeoGraphics examples not running correctly

I'm trying to work with the new GeoGraphics functionality in Mathematica 10, starting with the example given here. None of the code seems to run well for me, though. I try to run the first command: ...
68 views

### Optimizing complex functions

I am trying to optimize a function containing complex numbers, however I keep running into errors. Consider the simple optimization problem: ...
109 views

### Generating Z^*_n

I'm using Mathematica to illustrate basic number theory concepts in a graduate cryptography class. To generate elements of the multiplicative group of integers modulo $n$, i.e. $\mathbb{Z}^*_n$, I can ...
53 views

### Weird results of calculating a sum of binomials?

In[1]:= Sum[(-1)^k*Binomial[n, k]*Binomial[k, j], {k, 0, n}] Out[1]= (j Binomial[0, j])/(j - n) According to this output, for any ...
182 views

### Calculating eigenvalues of a large matrix takes a long time

I have a tridiagonal matrix (1000×1000) with each element equal to $1$ except {n, n} = 2. It takes 8 hours to give me the eigenvalues?!! Here is the code I used: ...
98 views

### Finding the equation of tangent lines where a function has a specified slope [closed]

A function is defined as f[x_] := 3x^4 + 8x^3 - 24x^2 - 48x + 19 I need to find the equation of the tangent lines at the points where the tangent line has a ...
58 views

### ParallelMap not using all of the available kernels

Please note: I cannot provide the code here, since the project is far too big to post at any Internet forum. I have a computer with eight logical cores. I have Mathematica Version 10.0.2, and I am ...
47 views

### how to write out this equation on Mathematica? [closed]

I have this equation that my manager would like to use on Mathematica, but I've only been learning how to use Mathematica for a few hours. I need to solve for Ax and also plot a graph. Please ...
110 views

### Missing elements using FinancialData

I have a list of stock symbols which I selected with FinancialData["Menbers"] that looks like the following list: ...
92 views

### Matrix of boundary distance between countries

I'm trying to generate a matrix of the boundary distances between all countries. First thing I tried was GeoDistance: ...
74 views

### Extract data pairs from a list of associations?

I am starting to use the new Associations, so this maybe an easy question, but I haven't figured it out. I have a list of associations, like: ...
50 views

### Simplify CubeRoot of meter cubes

Why Mathematica doesn't simplify CubeRoot of meter cubes to meters? r = Quantity[10, "Meters"]; v = 4/3 r^3 Pi; CubeRoot[% * 3/4 / Pi] returns ...
91 views

### Drawing a pair of lines to the x-axis and y-axis from a point along a curve

I have some plot like the following: Plot[Cos[x], {x, -10, 10}, AxesLabel -> {Style["x-axis", 12], Style["y-axis", 12]}, ImageSize -> {650, 650}] I'd like ...
51 views

### How can I modify text in a Graphics produced by Plot?

I have a Plot in a cell of a Mathematica notebook. The Plot was made with data that I no longer have. I want to modify the label of one of the axes, without running the plot command again (since I ...
36 views

### How to evaluate Poisson Bracket? [closed]

I'am new in Mathematica so please don't yell at me. I want to define Poisson Bracket in Mathematica 9 and evaluate it for two functions,but it didn't worked. Could you help me please? ...
272 views

### Inline documentation of “Properties”

Context I find the documentation has become a bit of a maze, in particular given the more recent convention of having keywords has strings rather than Mathematica Keywords. For instance, ...
118 views

### how to use InputField function within the manipulate function

I am trying to make a demonstration that can take in a matrix and create a vector field. Currently I have the demonstration all functioning but to define the matrix it uses sliders. I know they cannot ...
102 views

### How does Grid operate on Dataset?

The documentation (10.0.2) indicates that Grid can be used to display a Dataset; the section in guide/ComputationWithStructuredDatasets labelled 'Dataset Presentation'. However simply invoking ...
127 views

### How to combine the elements of two lists using a user-specified function

I have two lists of integers. From these lists I want to produce a list where each element is a fraction derived from a corresponding pair of elements in the original lists, the smaller integer of the ...
728 views

### Combining 2D slices into a 3D plot

I am currently trying to combine several 2D plots into one big 3D plot. The 2D-plots are simply input-results from calculations (so these things have 2D coördinates (x,y)). The results depend on an ...
377 views

### Simulate random data with correlation

I would like to simulate some random data e.g. between 0 and 1, but with a given correlation. In other words some data where the correlation between two datasets is e.g. a constant or within a give ...
84 views

### Extracting numerical coefficients from an expression

I have very large expression and I want to extract and sum up all the numerical coefficients which multiply the summands. For example, expr = x + 2*y + 3*z*w ...
178 views

### Manipulating elements of a matrix, to loop or not ?

I have a grid of values generated from a MATLAB evaluation. Most of these elements are 0, some 0.5 and the remainder 1. I'd like to write a mathematica script which reads in the CSV and then, in every ...
53 views

### ListAnimate for nested lists with two sliders

I have a very complicated function of three variables (a,b,c). Now I want to plot the function value as a function of a while ...
111 views

### Getting Mathematica 9 to export text and axes of a plot as vector graphics in SVG

Minimal working example: ...