Tagged Questions

Questions on the manipulation of List objects in Mathematica, and the functions used for these manipulations.

26 views

Removing 1 from FactorInteger

I am trying to remove the factor of 1 out of FactorInteger, so that I can search though numbers with common factors easier. Here is what I have already: For[n = 0, n < 10, n++; b = FactorInteger[...
79 views

How to generate a Markov Matrix efficiently

A Markov Matrix is a square matrix,which have two features: All elements great than or equal to $0$(But I hope all element great than or equal to $0.1$) All the columns add up to $1$ I have a ...
36 views

Remove columns basing on binary sequence

Possibly it is duplicate, still I could not find here elegant way to remove matrix columns basing on binary sequence. i.e. if I apply {1,1,0,0,1,0,1} to matrix it should delete columns 3,4 and 6.
90 views

Union sorting after ignoring some digits

I have a list with its bellow elements: {-0.7071067811865476, -0.7071067811865475, 0.7071067811865475, 0.7071067811865476} If I use ...
49 views

Nested lists replacing of elements

I have a list of the form SpecialCycle12={{{1, 2, 0, 0, 0, 0, 0}}, {{3, 2, 1, 0, 0, 0, 0}}}` And the list ...
56 views

Dividing a list into more, smaller, lists [on hold]

If I have the list {3,5,4,2}, is there a way to divide this list into smaller lists of the form {3},{5},{4},{2}?
151 views

Replacing elements in lists of a nested list

I have the following nested list ...
42 views

Can you unpack a list of values into variables in a With expression?

For instance, if I am trying to draw a graph with 5 vertices labeled a through e, and I want to draw edges connecting a and b, a and c, a and d, a and e, b and c, b and d, and c and e, I would run the ...
50 views

How to take a list and build sets of 2 elements without duplicates?

I am new to Mathematica so the answer to this question is probably easy. I have a list of 2D-points in the form {{x1, y1}, {x2, y2}, ...} Then I have a function that will take two points and test ...
168 views

Efficient way to compute a complement while respecting multiplicities [duplicate]

Suppose I have list2 which is a subset of list1. I want to get a res by deleting an element ...
61 views

I would like to pad a nested list like M = {{{a, b}, {c, d}}, {{e, f}, {g, h}}} with some constant "vector", e.g. {0, 0}. ...
473 views

Mysterious behaviour of Pick

As everyone knows, Pick can do amazing things, The most facinating phenomenon is that it can pick though all sorts of lists: The basic & pattern matching: <...
78 views

Double Sorting a Matrix

Say I have two matrices {{0, 1, 2, 2}, {2, 1, 0, 2}} and {{2, 1, 0, 2}, {2, 1, 2, 0}} I then sort by the first row ...
90 views

I cannot find the original post now, but I'm quite sure that there's an amazing post teaching us how to do Thread on ragged lists. but my problem is how to inverse ...
105 views

Strange Manipulate behavior

Running the following code and pressing the play button under b will input -2147483648 in b. ...
58 views

Creating a Dynamic Time Index Slider for List Animate Plot

I am trying to create an animation using ListPlot, which has worked, but I want to be able to see how time is changing (i.e. its dynamic value) as the animation runs. Here is my normal List Plot ...
78 views

How to define the following matrix

How to define the following matrix in Mathematica? A(n) = \begin{pmatrix} B_{1} & B_{2} & \cdots & B_{n} & 1 \\ B_{n} & B_{1} & \cdots & B_{n-1} &1 \\ \...
80 views

Interpolating initial conditions of orbits

I have a data file containing the $(x,y,p_x,p_y)$ initial conditions of two-dimensional orbits. Let's plot them on the $(x,y)$ plane. ...
47 views

Color a list of 2D points continuously

I have a list of 3-tuples. First 2 positions are coordinates in $R^2$, the third specifies concentration of a chemical at that point, which I want to render in color. Here's what the list looks like: ...
68 views

Predicting the initial conditions of orbits inside a closed curve

I have a data file containing the four orbital element $(x,y,p_x,p_y)$ of a two-dimensional closed loop orbit. Note that the exact implicit equation of the orbit is not known. The plot of the 2D ...
51 views

Passing each element of a list as an argument to a single parameter function [on hold]

Consider a single parameter function: g[w_] := w^2 +1; Consider a list: slist= Range[0, 100, 1]; Now when I apply function ...
210 views

How to select elements from a list of pairs based on 2nd element of the pair [on hold]

I have a large list of arrays of the following form ...
134 views

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Using select in a nested list [on hold]

I have a nested list of the following form ...
80 views

Creating sublists [duplicate]

I got this example in Mathematica references. v = ToExpression["a" <> ToString[#]] & /@ Range[1,44] Could someone explain to me the function of the ...
31 views

Arrange of several files

I am struggling to import my data. There are 400 files in CSV format with names organised by date like: Table1_20111003_YYYY_MM_DD_0000.dat. In each file over 20 colums and 86400 rows (seconds of ...
201 views

Transforming a list of the form {{{x, y}, z}, … } into the form {{x, y, z}, … } [duplicate]

This should be a fairly simple question, but I can't figure out how to do it. I have a list of points of the following form: ...
1k views

Riffle but not quite

Given the two lists below, is there an in-built command or otherwise neat way of accomplishing the desired output. ...
54 views

Not able to apply Scan in place of For loop [closed]

I have been advised to avoid procedural loops and use other functions like Scan,NestList, FoldList, NestWhileList, Inner and Outer. My worry is that if I have a need in which certain critical ...
59 views

Create a table indexed form a list giving a the index specifications

I need to create a table indexed form a list. e.g.: list={{i, 3}, {j, 4}}; would give the table Table[..., {i,3}, {j,4}]; ...
92 views

Group matrix values by column [closed]

Original Question: I have a list {{a, 1}, {b, 3}, {c, 1}, {d, 2}, {e, 3}}. I want to be able to group the the first number in each pair that has the same second ...
193 views

Selection of points based on position

I have a series of points, for example: points = {{0, 0}, {1, 3}, {2.5, 2.5}, {4, 4}, {6, 6}}; I want to join all points successively unless, for example, the y-...
79 views

Animating Differential Equations [closed]

I was tasked with creating a 3D animation in Mathematica, which aims to describe the movement of a football through space as it's kicked. There are several differential equations regarding this matter ...
44 views

Rotating the nested lists of a list [closed]

I have a nested list of the form List1 = {{1},{2},{3},{4},{5},{6}} I want to apply RotateRight to each of the elements in ...
50 views

Putting the elements of a list inside another list

I have the list list1 = {1, 3, 4, 5, 6} and want to put the elements of this list inside a list of 0's, ...
102 views

Changing the order of elements in a list

I have a list of the form list1 = {1, 3, 4, 2, 5, 6} and I would like to replace each of the elements in the position of represented by the previous number in the ...
53 views

Convolution with modified indices

I want to perform convolution for a sequence but instead of having the indices cycle from the ends periodically, I want to apply a function, specifically Abs, to ...
150 views

Selecting points inside a closed curve

Let's create a rather dense grid of initial conditions ...
43 views

Mapping AssociationThread over list with repeating keys [closed]

I have two lists. One with the same repeating four keys and the other with unique values. Both are the same length. I want to Associate the first list with the second list. So if that if the 5th ...
27 views

Splitting a list into sublists with different sizes [duplicate]

I have the list {7, 8, 9, 10, 11, 12, 13, 14} and would like to split it into a list of size 2, a list of size 3, and covert the remaining element into singleton ...
145 views

In the following example Nearest finds the nearest values between list1 and list2 and ...
912 views

Combining values in one column (or part) when values in another column (or part) match

Consider the following: ...
756 views

Using Partition to allow sublists of different lengths

As a minimal example, suppose I have a list of the integers from 1 to 25. Suppose I want to use Partition to partition the list into sublists of length 10 but ...
103 views

Calculating density of states from lists of momentum/energy data

I am trying to calculate the density of states for a 2D system given certain band structure data organized in a specific format. Below is an example of my procedure: Beginning with a simple 2 x 2 ...
72 views

How to split a SymmetricGroup into some PermutationGroup with smaller GroupOrder

Background I want to get a permutation list, so I use the SymmetricGroup(or use Permutations) to produce it when the ...
39 views

ListPlot[Transpose[{xx,yy}]] returns blank plot [duplicate]

This is complete mystery for me, but I am unable to plot the following data... I have two lists, that I want to ListPlot. The data is created in the following way (I edited the code for more clarity): ...
157 views

Operation with lists

I have created this code and was wondering if you could suggest a less convoluted way of solving the problem. I have two lists: ...
Given that I have a list $\{P_0,P_1,P_2,\cdots,P_7\}$, where, $P_i$ is a real number or a list like {x,y}/{x,y,z}. Now I would like to double some elements ...