Questions on the manipulation of List objects in Mathematica, and the functions used for these manipulations.
0
votes
1answer
20 views
Plotting points with different marker and different plotlegend
Currently i'm stuck at problem, where i have a sets of points, and I wish to plot these point with different plot markers, and also with different plot legend. The code is the following:
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6
votes
1answer
280 views
Deleting duplicates only if they are a certain kind of duplicate
I have a list of tuples like this:
{{1,a,b},{1,1,b},{1,a,a},{b,a,1},{b,a,b}}
I would like to find a way to delete all those tuples in the list that contain a ...
5
votes
1answer
98 views
How do we cluster separate curves in a set of data?
Below, I have included some data. (It is long, but I don't like to host data elsewhere and provide links that might some day be broken.)
Plotting this set of data,...
3
votes
2answers
50 views
Manipulation of 3D matrix
Assume that we have a 3D array x, and we would like to split it into 2D slices then cut every slice into some small patches and get all patches in single list ...
1
vote
1answer
24 views
How put a matrix in a row (with or without index titles) using mathematica
I am trying to put a 16x16 complex matrix in a row, with separated columns to real and imaginary parts (i.e a 1x512 matrix). Additionally this 16x16 matrix is generated by an operator ...
4
votes
3answers
53 views
Deleting sub-list that contains duplicates
I have a large list of uniform-length lists. What is an efficient way to delete component lists that contain duplicates? For three-item sub-lists, I have used the following code:
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3
votes
2answers
66 views
Converting a free variable in a pure function into a parameter that can be varied under iteration
Here I am going, as a matter of illustration, make a large string list:
l = Characters[WordList[]];
l = Table[DeleteDuplicates[l[[i]]], {i, Length[l]}];
This ...
1
vote
2answers
41 views
Adding each element in a list to the previous one
Having a list as follow:
l = {x1, x2, x3, x4, x5};
I want to add each element with the element before, so I did:
...
1
vote
2answers
28 views
Select equations with RHS!=0 from a list
I need to select from a list containing equations those having RHS not zero
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6
votes
3answers
258 views
Find an envelope of the list of points
I have a list of points as you can see in the image below. From this list of points, I want to generate a filtered list of points, which is the envelope. Additionally, calculate the area under the ...
3
votes
3answers
271 views
How to get median based on probability distribution?
From some calculation, I have a distribution of discrete data $(i,P_i)$ and then want to get the median based on this distribution. Naive way is to create a list
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1
vote
1answer
72 views
2
votes
3answers
59 views
Replacing an element of a matrix by a function of that same element
I want to replace an element of a matrix by a function of its current value. The code I'm using is as follows
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2
votes
3answers
64 views
Replace part of the element in a List of points
I have a question about the list of points - in the list below I would like to change the 3rd value of each point to another - like this:
{x, y, 0} to (x, y, 0.08}
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1
vote
1answer
64 views
3
votes
1answer
49 views
Go through three lists simultaneously, styling output based on data in all lists
I have three lists:
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8
votes
2answers
149 views
Visualize a string/sequence, emphasizing certain substrings
I need to visualize a sequence, with the ability to emphasize certain segments.
For example, take this sequence seq:
...
0
votes
2answers
50 views
Tuples of elements from list excluding anything with repeated values
What I would like to do is the following.
For a given list of elements; say (0,1,2,3,4) I would like to obtain all possible combinations of five, but not the ones with ANY repeated values. That is I ...
0
votes
0answers
33 views
Mathematica Bug? I cannot swap two elements list [closed]
I defined this function:
swapTwo[{}]:={};
swapTwo[{e_}]:={e};
swapTwo[{e1_, e2_, e3___}]:={e2, e1, e3};
or
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4
votes
2answers
149 views
Finding a specific string in a list
I have the following list:
l={"apple","orange","kiwi","APPLE","lemon"}
How can I make a command so the capitalised word would be returned?
So in this case the ...
1
vote
1answer
41 views
Select elements from 2D list with stride “t”
I would like to select elements from 2D list according to variable position (i.e. stride). For example:
x=Range@25 ~Partition~ 5
I want a command to select ...
2
votes
2answers
86 views
How to create a table of tables? [on hold]
Consider a situation when we need to create a table of tables, e.g.,
for
Tablei[i_] = Table[{a[i,j], b[i,j]},{j,0,LargeNumber,1}]
Create
...
6
votes
1answer
111 views
Working with a CSV data file with 100 millions rows (and 30 columns)
I am new to working with large datasets.. Currently I am struggling to upload a "big data" file into Mathematica. The file is in the CSV format and has 14GB. There are 100 millions of rows and 30 ...
1
vote
1answer
36 views
ListLogLogPlot origin issues and numerical instability
I have the following long functions f1and f2 dependent on parameters ω and ...
6
votes
1answer
139 views
Elegant way of partitioning in two starting from the second element?
I wrote a code for partitioning a list. I want to group them into two groups following the same pattern: 1. element added, then 2. and 3. are omitted, then 4. and 5. added and goes like this. ...
4
votes
1answer
66 views
0
votes
1answer
26 views
Valid Array generation for ListDensityPlot
I want to create a ListDensityPlot of T vs k, and to do so I am not able to achieve an ...
6
votes
4answers
247 views
Find the list that best matches reference list
I need to find how well several different lists match a reference list. I'm looking for a percentage or some kind of similarity score.
For example,
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5
votes
1answer
97 views
Replace targeted elements in first level of list only
I have a list where some elements are strings or sublists:
...
1
vote
1answer
38 views
Convert Part of Subscript Files to Math Form
I have french subscript file here:
https://uploadfiles.io/iehon
If you download it an open it with Word, you can see that the math sections are but between $<i>$ and <\i>:
To import the ...
3
votes
2answers
68 views
Manipulating lists
Assume I have two lists:
A[1,1]={1,2} and A[2,1]={3,4}.
When I create a table
...
0
votes
1answer
60 views
Position for array
how does Positionwork for array? In particular if i have something like this:
...
1
vote
1answer
41 views
How to separate rows with commas in imported CSV
I imported a CSV file that uses commas as its delimiter, but some fields also contain commas. When I import the file into Mathematica as follows
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10
votes
5answers
653 views
Taking the square root of the first element of a list
If I have a list for example :
{{4,1},{9,2},{16,3},{25,4}}
Is there a command that replaces the first element by its square root and returns a list ? In the ...
1
vote
1answer
85 views
Study frequency of occurrence of alternatives in a test [closed]
There is a test with 5 alternatives A, B, C, D, E, I need to study the frequency of occurrence of these alternatives in a test of 80 questions, "n" times
I can not think of a way to program it, help ...
2
votes
1answer
50 views
How do I find all local minima in a multidimensional array?
I'd like to find all local minima in an array of data. The array I'm working with is 3D, but I'll use a 2D example to illustrate what I mean:
Say I have the following array:
...
3
votes
1answer
44 views
Simulation using Manipulate within Manipulate
Suppose there is a list of matrices (say m matrices), matC. The first element of this list is considered as the Benchmark matrix ...
2
votes
2answers
43 views
Convert List of Equations To Coefficient Matrix
I have the following list of 2 equations (but generally I have much more than 2 equations):
m= {A1*x+B1*Sin[x]-C1*Cos[x],C2+A2*Cosh[x]}
How could I ...
1
vote
1answer
32 views
How to select random number of elements from a list?
Assume that I have a list
a = {1,2,3,4,5,6};
and I want to have a function that outputs a subset of the list such that with probability p=0.2 each element will ...
1
vote
1answer
42 views
Mapping over a piecewise function
This is a followup to a question I posted earlier today. Suppose you have a piecewise function such as "snap=max[x,0]= x if x>0, 0 otherwise".
Then you would think that it must be straightworward to ...
1
vote
2answers
45 views
Slider for a list of real numbers versus a list of matrices
Suppose that there are two lists, where capital letters in List1 denote matrices.
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9
votes
3answers
454 views
Create lists of equivalences from pairs
I have a list of pairs, e.g.,
ex1={{1,2},{1,3},{2,3}, {4,5}, {6,7},{6,8}, {7,8}}
that I would like to merge into the list
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2
votes
4answers
73 views
Identifying maximal element in a list with case distinctions
I need to create code that identifies the positions of all maximum elements of a list. I already know that if myList contains only numbers, I can do
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2
votes
1answer
48 views
Select elements in a list of tuples of quaternions that satisfy a condition
I defined 24 quaternions using the Quaternions package and i create the list of all possible 4-tuples using
ListQuad = Tuples[ListQuaternions, 4]
where ...
6
votes
2answers
253 views
how to construct a special matrix out of two lists
I have two lists as:
abs = {a1, a2, a3, a4};
trs = {t1, t2, t3, t4};
I like to build the following special matrix:
...
0
votes
1answer
56 views
Converting a list of associations into a single association
How do i smartly join a List of Associations (eg. returned by ParallelTable) such that i get a single Association?
...
4
votes
2answers
72 views
Different plotting lines and points when using lists
Does anyone know how I can to draw a line connecting a list of data, while the dots are a colour and the line another colour?
As an example, the following is a list of data and how I plot them
<...
10
votes
0answers
84 views
What changed in String handling between 11.0 and 11.3?
I was trying to optimize some String-handling code here using my standard trick of converting it to a list of bytes first and using basic list operations instead of ...
12
votes
10answers
1k views
Given a list of integers, find the largest sum of a contiguous subsequence
Given a list of integers, find the largest sum of a contiguous sub-sequence.
{1, 2, 3, 4, 5, -1, 7, -4, -2}
(* 21 *)
And print the sub-array which is ...
3
votes
5answers
94 views
In a given unsorted list, find the maximal ascending sublists of at least two contiguous elements
In a given unsorted list, find the maximal (strictly) ascending sublists of at least two contiguous elements.
input={1, -1, 2, 3, 4, 0, -2, 5, 0}
and
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