Questions tagged [list-manipulation]
Questions on the manipulation of List objects in Mathematica, and the functions used for these manipulations.
7,366
questions
2
votes
4answers
221 views
Use replacePart from an element n to an element m of a list
I would like to replace a part of a list from an element n to an element m by zeros.
I believe the function ReplacePart could be useful
Example: I want to replace elements from 2 to 4 by zeros :
...
1
vote
0answers
27 views
What subsequences does SequenceReplace consider
Consider SequenceReplace[{a, b, x, x, a, c}, {a, e_} :> e].
What subsequences does SequenceReplace consider?
The ...
0
votes
1answer
61 views
Using :> vs -> in SequenceReplace
The first example on the page for SequenceReplace is the following:
SequenceReplace[{a, b, x, x, a, c}, {a, e_} :> e]
...
7
votes
3answers
327 views
Flatten simple list
I know this is probably a very silly question but I am trying to get {x,y,z,p} to be x,y,z,p.
For this I am using Flatten in this way:
...
2
votes
2answers
54 views
0
votes
3answers
333 views
Python recursive bisection algorithm to Mathematica
I've been sitting on this problem for a while and i am kind of stuck. I am pretty new to Mathematica and have been trying to implement a recusive Algorithm, which splits/bisects a list of items in ...
3
votes
3answers
325 views
How to find a median of odd and even numbers from a list of numbers
For a given list, say {94,35,47,29,86,40,46,72,87}, how can I find a list of even and odd numbers.
Here is the output after trying with the suggested solution in the answer.
After putting the number ...
3
votes
1answer
114 views
Sublist creation, splitting and joining
I have a not very usefully-formatted string list and I would like to create certain sublists from it.
...
0
votes
1answer
45 views
ComplexListPlot not ploting [closed]
In a nutshell i have to plot a sequence of complex numbers to roughly see if it converges or not.
I've created the list using the following
...
0
votes
1answer
28 views
How to deploy cloud application that graphs two companies net profit
What I want to do is to deploy a cloud application that would compare two stocks and (for bonus if it is possible) to also compare the net profit of two companies on a graph.
I tried:
...
5
votes
3answers
193 views
Extract specific string from a list of strings
My question is similiar to previous questions (see here or here), although the issue is maybe somewhat more complicated:
I have a list with strings like this:
...
10
votes
1answer
233 views
Understanding Partition
I came across the difficulty of understanding the logic of interaction of the fourth and fifth arguments of Partition.
Here is an example:
...
2
votes
1answer
126 views
Cannot assign variable value inside Do Loop
This is more of a conceptual problem.
Suppose I have three lists.
x1 = {1, 2, 9, 10};
x2 = {5, 6, 7};
x3 = {9, 10, 13};
Now, I wish to keep only the first two ...
1
vote
1answer
46 views
Is there an efficent way to rearange lists of lists where transposing the whole list is no option?
I have a list of lists of lists, listing pairs of pairings. {{{a,b},{c,d}},{{a,e},{f,g}},....}
I want to apply a function to this list that gives me a 4 level list where each first level element ...
3
votes
3answers
197 views
1
vote
2answers
87 views
4
votes
3answers
105 views
Thread map to 2 lists of inputs, including the nondiagonal terms
Given a function f and two lists of variables
{a1,a2,...}, {b1,b2,...}
How can I generate a following list
...
2
votes
1answer
95 views
Using StringExpression in a string list
I'm trying to search in a list of strings those who match a pattern. But it seems that StringExpression in functions such as ...
7
votes
4answers
366 views
AnyTrue is too good (compared to MemberQ)
Let L be a list of integers, and ⓝ denote an explicit integer.
I've thought the most natural way to tell whether ⓝ belongs to L is
In[1] MemberQ[L, ⓝ]
But there ...
3
votes
1answer
107 views
Is it possible to get a graph for Taiwan water area
I tried to get a graph for water area in Taiwan, but somehow it doesn't seem to work:
...
2
votes
3answers
83 views
creating sublists by rules
I have a list:
lis = {{ghi ,0,1,0,1,3,prq ,2,4,3,2,5},{abc 12-3,0,0,2,0,1,def 1-3,0,1,1,1,3}}
I'd like to:
delete each element whose first sub-element does not ...
4
votes
5answers
321 views
Creating sublists by rule
I would like to make a sublist consisting of the four elements that follow each occurrence of 1, 2 in the list:
...
5
votes
3answers
426 views
How to sort first two numbers in sublists
Given
t7 = t8 = {{3, 5, 1}, {19, 2, 9}, {4, 3, 1}, {19, 0, 8}};
I want to Sort the first two numbers in each sublist and keep ...
2
votes
1answer
58 views
How to plot a double log scale at the x axis?
I need to plot my Data with a double Log Scale on the x axis. So basically apply ListLogLinearPlot two times. Does anyone have any ideas how to do that?
0
votes
2answers
55 views
Selecting Keys when Lists are used as Keys
Analyzing a sequence after restructuring it, Counts returns a sequence similar to below:
...
1
vote
0answers
65 views
How do I carry out a partial row reduction of a matrix? [closed]
I have a large matrix with more columns than rows. I have attempted to row reduce the matrix using Mathematica's RowReduce command. I have been able to do this ...
0
votes
3answers
76 views
2d Binning of event-lists
I have a large file (list) with events, each of which contains many observables and is thus a list by itself. The structure of the event list is then as follows:
{{a1,b1,c1,d1,...},{a2,b2,c2,d2,...},.....
1
vote
1answer
65 views
Appropriate syntax for constructing frequency table and histogram from experiment with three or more dice?
if I say to input 3, how do I get MMA to make me a table with all the cases on the left, in the center their frequency and on the right a histogram,bar chart, or some other way to represent the above.
...
2
votes
1answer
52 views
0
votes
0answers
59 views
Evaluate a function with 3 different variables for the whole list of each variable
I have a function with 3 variables
f[t1,t2,t3]
Each function has a list of values
...
1
vote
1answer
58 views
Collect data only for odd positions [closed]
I have data set, say,
list={{x1,y1},{x2,y2},{x3,y3},{x4,y4},...,{xn,yn}}
How can I construct the following list ?
...
2
votes
2answers
209 views
How to create a 2D mesh along a specified path?
I am trying to create a mesh along specific lines connecting specific points. Here I used Subdivide to create n steps along the ...
-1
votes
1answer
72 views
Costly function inside nested Modules [closed]
The function initDataTable simply reset all data to Black first, then set the bottom right quarter to ...
3
votes
3answers
150 views
How to produce {{1,40},{2,20}} from {{1, 10}, {2, 20}, {1, 30}}?
My attempt below produced a warning:
Total::normal: Nonatomic expression expected at position 1 in Total[y].
...
4
votes
2answers
430 views
Is there any simpler way to generate dominoes?
I want to make a list of dominoes. My attempt is as follows.
Subsets[#, {2}]~Join~Thread[{#, #}] &@Range[0, 6]
{{0,1},{0,2},{0,3},{0,4},{0,5},{0,6},{1,2},{1,3}...
3
votes
1answer
149 views
Function with variable-length nested list
FromPolarCoordinates has a very nice feature: if you supply several points, e. g. {{r1,phi1},{r2,phi2},...}, it will return a ...
3
votes
2answers
154 views
4
votes
1answer
165 views
Find the longest sequence of "1" in a SubList
I'm trying to return the sublist(s) with the longest sequence of 1, although my code is working in a majority of cases, there are exceptions that I don't understand .
Example:
...
1
vote
1answer
68 views
Picking/selecting elements from a list
I'm trying to pick/select elements from a list based on another list's value. I haven't been able to implement the solution given to similar questions, such as this and this. Here is a MWE:
...
2
votes
3answers
113 views
Exporting specific frame of ListAnimate
Imagine I have a certain list of Graphics-type objects that I then incorporate into ListAnimate
...
2
votes
1answer
56 views
Mathematica association does not work on symbols
Question about using an association within Replace.
If I have an association which contains symbols like so:
...
0
votes
0answers
20 views
Applying a function to a number of variables stored as a list [duplicate]
If I have a function of several variables $f(a,b,...)$, where the variables are stored in a list
{a,b,...}
how do I call on the function? The following:
...
2
votes
3answers
304 views
How to ask Mathematica to subtract each adjacent pair in a list, and then, sum them?
If I have a list of numbers as (the number of elements in this list is even)
list={1,23,32,54,65,76,87,98,109,110,...}
How can I ask Mathematica to subtract each ...
0
votes
0answers
36 views
Finding the integer values of $p$ and $l$ for which a function $b(p, l)$ is divisible by $n$
I wrote the code in the attached image to find the integer values of $p$ and $l$ for which a function $b(p, l)$ is divisible by 3. Does anyone know of a nicer way to achieve the same result? Perhaps ...
0
votes
1answer
42 views
Construct a matrix from a given data set and perform subsequent operations
I have data set, say, {${x_i, y_i}$} where $i$ varies from $1$ to $n$. Now, how can I construct the matrices
$M_i=\{\{1,x_i,x_i\},\{\ x_i,1,y_i\},\{x_i, y_i, 1 \}\}$
and perform the following ...
1
vote
1answer
28 views
Automatically retrieve evaluation spot row number
Suppose I need to define a matrix of the form
{{a, b, Reduce[a<b]}, {c, d, Reduce[c<d]}, {e, f, Reduce[e<f]}}
but with a lot more rows and automating the ...
2
votes
1answer
62 views
0
votes
1answer
67 views
Does default 'Sort' generate always the same result? [closed]
Does default 'Sort' output always the same result regardless if we change its order?
Suppose that
L = {E1,E2,E3,E4,E5}
(*here E1,..,E5 means any possible ...
3
votes
1answer
116 views
Why do these two calls to Apply return different results?
In the following example, why do these two calls to Apply return different results?
...
0
votes
2answers
87 views
Order multivariable polynomial terms in order of total degree
Given a polynomial, lets say for example $f(x,y) = (1+x+y)^2 = 1+2x+x^2+2y+2xy+y^2$, I'd like to be able to order the terms of the polynomial by total degree, either in increasing or decreasing order (...