1
vote
3answers
103 views

MapThread (or alternative) for adding fixed option

I currently use MapThread[f, {{a1, a2}, {b1, b2}] for obtaining { f[a1, b1], f[a2, b2] }. Is there a version (or alternative) ...
1
vote
2answers
377 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 ...
7
votes
1answer
212 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 ...
0
votes
1answer
65 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.
4
votes
2answers
158 views

Paired Bar Chart with negative values

Dear Mathematica group I want to plot negative values using PairedBarChart in V9 However, with this code ...
0
votes
1answer
140 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 ...
1
vote
1answer
128 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 ...
3
votes
2answers
167 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 below,...
3
votes
2answers
193 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: ...
7
votes
2answers
228 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 ...
3
votes
3answers
256 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: <...
0
votes
1answer
115 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: ...
6
votes
2answers
179 views

Generating $\mathbb{Z}^*_n$

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 ...
0
votes
1answer
66 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 ...
0
votes
3answers
287 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: <...
0
votes
2answers
279 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 ...
1
vote
0answers
108 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 ...
-1
votes
1answer
54 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 help....
1
vote
1answer
168 views

Missing elements using FinancialData

I have a list of stock symbols which I selected with FinancialData["Menbers"] that looks like the following list: ...
1
vote
2answers
209 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: ...
0
votes
2answers
226 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: ...
1
vote
1answer
59 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 ...
0
votes
1answer
148 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 ...
0
votes
1answer
56 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 don'...
1
vote
0answers
51 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? ...
17
votes
2answers
321 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, ...
1
vote
2answers
412 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 ...
6
votes
2answers
145 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 Grid[...
3
votes
4answers
180 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 ...
7
votes
4answers
1k 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 ...
9
votes
3answers
456 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 ...
2
votes
2answers
174 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 ...
1
vote
2answers
221 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 ...
1
vote
1answer
86 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 ...
1
vote
1answer
197 views
0
votes
1answer
245 views

Incorporate error bars to best-fit curve [closed]

I have managed to get mathematica to perform a best fit curve. However, I wish to add error bar to the curve, how do I do so?
2
votes
1answer
107 views

ParallelMap doesn't work with an Association. Is this a bug?

I receive a ParallelCombine::nopar1 error when executing ParallelMap[Identity, <|1 -> 1, 2 -> 2|>] Is this an ...
2
votes
1answer
168 views

How to implement the dual Lagrange?

I have seen in the Pang book of data mining the following example: ...
2
votes
1answer
64 views

UnitConvert of a Quantity whose value is a function of a Quantity

I am having trouble with UnitConvert when the QuantityMagnitude contains an embedded Quantity...
4
votes
1answer
139 views

The case of the disappearing locators

I have a complicated Manipulate that uses multiple locators, and need to document the output by saving the graphics to a file. The problem is that when I try to save the graphics, the locators ...
2
votes
1answer
176 views

How to use ContourPlot3D with a constraint

I want to draw $$G=G(P,T)=-k*T(1+\log{\frac{(V-1)T^{3/2}}{\Phi}})-\frac{a}{V}+P*V$$ but $V$ is an implicit function of $P$ and $T$, which is $(P+\frac{a}{V^2})(V-b)=k*T$ I tried to solve for $V$ ...
9
votes
2answers
200 views

Area of Self-Intersecting Polygon with Repeated Vertices

So Mathematica uses an even-odd rule for self-intersecting polygons, both when rendering them and when calculating their area: ...
0
votes
1answer
188 views

How to obtain Laurent series coefficients of an (almost) arbitrary function?

I have observed that Series in Mathematica assumes that the given function is smooth in the point around which one wants to perform series expansion. For instance: ...
13
votes
1answer
278 views

Why does cropping an image improve TextRecognize so much?

I am trying to use the TextRecognize function to extract data from certain screenshots. This is already a cropped version. Using TextRecognize on this yields <...
1
vote
2answers
114 views

Abs[Sin[4a]] not equal to 2Sin[2a]Abs[Cos[2a]] for a in [0,\pi/2]

I have a long expression which is not fully simplified because Abs[Sin[4a]] is considered different from 2Sin[2a]Abs[Cos[2a]] ...
7
votes
6answers
332 views

PlotLegends for ListPlot with more than 15 curves?

fixed in 10.1 (windows) I'm running into trouble getting the right PlotMarkers in the legend of a ListPlot of many curves. ...
0
votes
2answers
73 views

How to change list to a list of points

I have a list of angles {a1, a2, .... , an} and I would like to have a list of points ...
2
votes
1answer
164 views

Change the colors of individual atoms in a .mol or XYZ file

Similar to (Changing the atom color for plotting xyz-files), I want to take a molecule and then simply change the colors of individual atoms. I don't want to change all atoms of a type to a color (say,...
3
votes
1answer
297 views

How can I make a pretzel shape using Bézier curves?

I am trying to make a pretzel shape,but I cannot seem to get the loops even. Eventually, I need to make the pretzel shape loop in 3D so I need to nail the 2D concept first. Here's what I have so far....
2
votes
1answer
73 views

ArgMax and result readability

Trying to maximize a two-variable expression and to get variables' values at maximum points: ...

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