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

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2
votes
0answers
46 views

Defining a function which takes lists as it arguments and threads over them [closed]

I want to define a function with lists as variables, which has the form like m = Table[2, {i, 5}]; f[x_, y_] = m*x + x*y; x and y are list variables; m is a ...
2
votes
0answers
75 views

How do I flip x and y value of a list in mathematica? [closed]

I am very new to mathematica. I have been trying to the following without any success. I have a list like this : data = {{1,2},{3,4},{5,6}}. I want a list ...
2
votes
0answers
55 views

pattern matching and applying a function, not working as expected [duplicate]

Consider the following code G[x, y] /. a_[b__] -> Total[a @@@ Permutations[List[b]]] I expect it to give G[x, y]+G[y,x] ...
2
votes
0answers
58 views

Compilation of a function that needs to call Subsets

I'm working on a code that runs many (easy) operations on combinations (subsets) of different size (6, 7, 8, 9) taken from a big set of numbers (normally more that 40). So, this means the code has to ...
2
votes
0answers
65 views

Choosing a List as VertexWeight for a TreeGraph

I would like to map every vertex of my TreeGraph to an List. ...
2
votes
0answers
105 views

ParallelTable and expensive functions

I would like to build up a 2D-Table using ParallelTable as follows ...
2
votes
0answers
53 views

Replacing list elements by other list elements [duplicate]

I am a beginner of Mathematica and need some help for the following issue. I have the following two lists: ...
2
votes
0answers
222 views

Faster Ways to compute recursive summation

It takes a long time to compute the summation below, and I'd like to know if there are some better ways to compute things faster. I have used $3$ ways to calculate, but they are very unsatisfactory. I ...
2
votes
0answers
36 views

Adding Elements to a List of Lists [duplicate]

I'm trying to do the following: Given a function f[x,y], I want to turn the list {{x1,y1},{x2,y2},...,{xn,yn}} into ...
2
votes
0answers
71 views

Produce {f[x],g[y],h[z]} in as many ways as possible [duplicate]

I have two lists of equal lengths but for my task I will use 3-element lists , namely {x,y,z} and {f,g,h}. The first contains ...
2
votes
0answers
73 views

The number of real values assumed by combinations of complex roots of a decic

Define complex conjugate as the pair of complex numbers $a+bi,a-bi$. Assume you have 5 such pairs and they are the 10 roots $x_i$ of a 10th-deg equation with integer coefficients. In general, how many ...
2
votes
0answers
65 views

How to create a ListPlot containing two lists? [duplicate]

I'm trying to plot a set of points where one list corresponds to the X values another list corresponds to the Y values. I have ...
2
votes
0answers
411 views

Generating a function which outputs possible chemical reactions

I want to make a list of chemical reactions and I write them down in a $\require{mhchem}\LaTeX$ format. They are of the following form $$NA_n^i+MB_m^j \rightarrow \hat NA_{\hat n}^{\hat i}+\hat ...
2
votes
1answer
56 views

Dropping rational coefficients

I have a list of expressions (they all are exact numeric quantities, not containing any variables), some of them have integer or rationals coefficients, or complex coefficients with rational or ...
2
votes
4answers
124 views

List Manipulation Via Conditionals

I'm trying to convert one list to another by applying a condition on the list's elements. But I can't figure out how to do this in mathematica's language. Python example below ...
1
vote
4answers
5k views

Creating a data1 versus data2 plot?

I have a table of data with multiple rows and columns, and I have to make a versus data table using two of these columns. Essentially, I have to set one column of data (column 3) as the y-axis and ...
1
vote
2answers
269 views

How to blend some colors on a curve

I need to define a color gradient on a 3D curve, but I'm having some problems with this. Suppose we have a 3D curve defined as a parametric function of some real variable ...
1
vote
2answers
673 views

Computing 10-dimensional volume of a 9-sphere [closed]

I'm trying to compute 10-dimensional volume of a 9-sphere with radius r using Monte Carlo. ...
1
vote
3answers
200 views

Selecting a Point that has the Lowest Absolute x/y-coordinate From a List of Points

Given that there is a set of points, for example, {{3,4,2},{5,2,-1}}. How do I go about selecting the point that has the lowest absolute x, y or z-coordinate from ...
1
vote
4answers
110 views

Drop row if sum of part of row is equal to zero

My problem is the following: Suppose I have a matrix A which looks the following: ...
1
vote
3answers
2k views

Loop through a list and select elements

I am new to Mathematica and I have no idea how to make a basic for loop work. I want to loop through the elements of a list: Range[45, 200]. I want to select the ...
1
vote
3answers
94 views

Getting a list of x coordinates of intersection points of two functions

I have two functions, f[x_] := 5 Sin[2 x] g[x_] := (5 x + 2)/(x + 2) I am trying to find the x coordinates that intersect ...
1
vote
5answers
158 views

Select a certain row among the duplicates

I have the following problem: I have a (a lot)*3 table, meaning that I have 3 columns, say X, Y and Z, with real values. In this table some of the rows have the same (X,Y) values, but with different ...
1
vote
1answer
6k views

Table - find index of the maximum element [duplicate]

Let's suppose that I have table t = {1.23, 3.4, 10, 34, 1.78, 0.98, 12.56}. To take the biggest element I can use Max[t] ...
1
vote
4answers
174 views

Removing all values from a list that satisfy a given condition

Suppose I have a list, list = Table[{n}, {n, 1, 5}] (* list = {{1},{2},{3},{4},{5}} *) and I want to remove all values from this list that are greater than 3, so ...
1
vote
3answers
615 views

How to expand the size of the matrix automatically?

I have a matrix in 2x2 a ={{x, y}, {z, u}} I want to expand this matrix 3x3 b ={{x, y, y}, {z, u, x}, {z, x, u}} 4x4 ...
1
vote
4answers
431 views

Summation over 3 lists

I have three lists. As an example, a = {10, 5, 6, 8, 7}; b = {4, 8, 9, 7, 9}; c = {7, 5, 12, 4, 1}; I want to get: $$ x(i)=\sum ...
1
vote
3answers
233 views

Separate an array in two arrays, the even and odd terms being separated in these two arrays

How can I separate the odd terms in one array and the even terms in another array,i.e., go from a={1,2,3,4} to aeven={2,4} ...
1
vote
3answers
222 views

Code hanging inside a For loop

I'm pretty new to Mathematica (and functional programming in general). I'm working on some code to find winners (maximal values) in a list. The code I have that is hanging is this line. ...
1
vote
2answers
819 views

How do I divide the columns of a matrix by the sum of its elements?

I am trying to create a transition matrix for a network. In order to do this, I need to sum down the column (the out degree), and then divide the column by the out degree in order to normalize it. ...
1
vote
2answers
246 views

Thread over a nested list top to bottom until non-list elements are found

I have a nested list: list = {1, 2, {3, 4}, f[a], {2, h[b]}} I would like to apply a function g to all elements of the ...
1
vote
3answers
241 views

Logical operations on a list [duplicate]

Possible Duplicate: Applying And to lists of Booleans I have two lists filled with logicals: ...
1
vote
3answers
108 views

Scatter plot with smooth lines [closed]

I have two lists of data between which there may be some functional dependence. I want to plot one against the other (hence scattered plot) where the points are connected by smooth lines. In ...
1
vote
2answers
166 views

How to generate a range of numbers

Is there a quick and dirty way to generate a list of numbers from 1 to some arbitrary large number in order such that the digits of each number are only 0's, 1's, and 2's? I tried doing ...
1
vote
4answers
152 views

Pure function, one slot refers to List-position

I used all my google-fu trying to find how to make this work; read the docs as well. What have I missed? I feel sure this can't be a new question, but I can't find anything Here is is: ...
1
vote
4answers
157 views

Check if a scalar falls within the range given by sub-arrays of a matrix

I have a rank 3 matrix: r = {{{1, 10}, {19, 71}, {111, 159}}, {{1, 5}, {25, 63}, {118, 132}, {164, 185}}, {{1, 19}, {28, 49}, {157, 203}}}; and each of the ...
1
vote
2answers
417 views

Mapping functions over multiple lists

I am not sure if this is a duplicate. Spent some time looking over list-manip questions. I’d like to know the Quickest Way to achieve the following Mapping of a function over multiple lists. ...
1
vote
4answers
271 views

Add Brackets to a string list

Hello stackexchange community! I have a stringlist with a value and his error for eg: {{"12","1"},{"13","2"}} Now i want to output this as something like this ...
1
vote
1answer
223 views

Map a function conditional on elements at multiple relative positions in a list

I figure this question has many solutions, and if an answer already exists it would be nice just to be referred to it. I need a function that 'maps' over my list and produces a list of equal length ...
1
vote
3answers
180 views

Listing elements starting from 0

The first element in a list v in mathematica is denoted by v[[1]] and subsequent ones are then ...
1
vote
3answers
202 views

How to manage list of list of rules?

Considering we have a list: str = "{1 -> {a -> aa, b -> bb}, 2 -> {2a -> \"{b -> bb}\"}}" Bringing this to expression gives: ...
1
vote
2answers
183 views

How do I disorder a list in Mathematica?

Given a list like this (the original list is much longer), how I can get a completely unordered list and save it in plain text? I change the file names (names at random), using a length of 5 digits, ...
1
vote
6answers
295 views

Converting two lists into a list of tuples [duplicate]

I wonder how I can turn the list $\{a_1,...,a_n\}$ into the new list $\{(a_1,1),...,(a_n,n)\}$, i.e $a_k \mapsto (a_k,k)$, how do I do that? I figured the function Tuples might work, but it just ...
1
vote
2answers
320 views

What quantity is this “length” called?

tmp = {x, y, z}^{1, 2, 3} Times @@ tmp Length[%] This gives a length of 3. But I was expecting 1. What is exactly this "length" of x*y^2*z^3 called? I would ...
1
vote
6answers
225 views

Deleting missing data with CountryData

I need to delete all of the missing entries after executing this line: ...
1
vote
2answers
75 views

Replacing a specific pattern of values at level 2 in a list

I've a list of lists, tl = {{True, False, m12}, {False, m22, m33}, {m32, False, True}} and each nested list has the same length, What is the proper way to ...
1
vote
2answers
158 views

How can I create a list containing the normalized element-by-element product of two given lists?

I have to calculate: How can I create such a sum? Do I have to set the factors of each term manually (one by one), like G1 = 1, H1 = 1, G2 2, H2 = ....? ...
1
vote
3answers
212 views

How to replace identical positions in two different lists

Assume that I have two lists like : list1={1,2,3,4,5}; list2={a,b,c,d,e}; I want to replace some elements from list1 into ...
1
vote
1answer
147 views

Ways to access lists inside lists

I have gone through some reference material but I am not getting really good links that will help me grow understanding of ...
1
vote
2answers
227 views

Plotting array of vectors with conditions

Given data in the form list={{{1,2},{3,4},{5,6}},{{7,8},{9,10},{11,12}},...} a matrix where elements are 2-element vectors, what is a efficient way to plot this ...