Questions tagged [list-manipulation]
Questions on the manipulation of List objects in Mathematica, and the functions used for these manipulations.
8,817
questions
5
votes
2
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167
views
A Nothing for Associations
In the same way that Nothing disappears from Lists, is there a built-in that when it appears as the value in an association the ...
- 5,484
-1
votes
1
answer
57
views
A general term of this sequence [closed]
My question is about the set theory.
I have c[0]={{1}} and i want to define c[n] as follows:
...
2
votes
0
answers
39
views
Delete list item if message is thrown
I have a nested list with each element containing FindRoot like this:
{FindRoot[a,b], FindRoot[c,d], FindRoot[e,f],...}
...
- 147
1
vote
2
answers
105
views
FindFit; not a valid variable [closed]
I am trying to fit the function in model, however I get
General::ivar: 5000.` is not a valid variable.
this error.
My code is that and
...
- 13
6
votes
5
answers
637
views
0
votes
1
answer
36
views
Mathematic doesn't compute absolute value of difference of solution of ODE from two different numerical methods
While trying to compare the solution to an ODE by 2 different numerical methods Mathematica gives a wrong result.
More specifically I have te code.
...
- 125
2
votes
1
answer
61
views
From list shown below - highlight in BOLD the pair with the highest value
I have been trying for sometime to achieve the following:-
Given the list - {{"E", 3}, {"D", 2}, {"S", 2}, {"M", 2}} a list of pairs which maybe 4 pairs - more ...
- 21
2
votes
2
answers
245
views
1
vote
1
answer
133
views
Creating and exporting .dat file as desired
Please help me create a .dat file with the data format is
as in the link given below
https://pastebin.com/CXq0N3aT
And export the file.
Part of the data format in ...
- 123
6
votes
5
answers
811
views
How can I apply a function only to even-index elements of a list?
A = {1, 2, 3, 4, 5}
and, Dd[P_] := P + 1
How can I map "Dd" into "A" such that the outcome is: {1, 3, 3, 5, ...
- 61
0
votes
1
answer
55
views
How can I outline my figures?
I am currently producing some figures, all using the same colours. This, however makes them impossible to distingis from one another.
This is my code
...
- 127
4
votes
2
answers
118
views
Extracting the second largest and minimum values, and plot
How to extract the second lowest and the second largest values of each row, and plot them as upper and lower graphs? I try with TakeLargest (or ...
- 173
0
votes
1
answer
50
views
How to compose output of NDSolve with another function? [duplicate]
If I want to solve some ODE by NDSolve but want to make a table of the solution $u(x)$ NDSolve gave me evaluated at another function, say $x(i)$, how would I do that,
here's an example
...
- 125
7
votes
5
answers
430
views
Smart way to remove rules from lists, leaving just values, specifically from FindMinimum output
I would like to know if there is a direct way to remove the rules from a list of rules.
I know that, simply, this can be done with:
...
- 561
0
votes
1
answer
99
views
How to find multiple zeroes of a single function
This is the problem I am solving.
I have defined my wanted equation as it is shown on the picture. Finding the first 0 (root) is not difficult with using FindRoot function.
The problem that i am ...
- 97
1
vote
0
answers
78
views
How to DeleteDuplicates from a list of Rules having set to different values whereby we wish to drop the last occurrence?
About This Function
This will eventually set default values for Options based on the end users preferences so that no OptionsPattern need ever be set. The symbol<...
- 1,977
2
votes
3
answers
140
views
Insert a dynamic vector into a matrix
If I have the following dynamic vector
Cs[NN_] :=
Table[{Sin[(2*i - 1) τ], Sin[(2*i - 1) τ]}, {i, 1, NN}] //
Flatten
The size of Cs depends on the integer ...
- 1,215
7
votes
3
answers
260
views
Removed all undefined from a list of rules
My output from NSolve is a list of rules, most of these are undefined, I want to remove those rules.
More specifically I have a list
...
- 359
0
votes
1
answer
79
views
3D Plot using data from a .dat file
Suppose I have a .dat file, that I could easily manage to import it and it read as below
...
- 664
3
votes
1
answer
79
views
10
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6
answers
222
views
Joining sublists of nested list based on sublist position
I have nested list with sublists of varying lengths like this:
list={{a,b,c,d},{e,f},{g,h,i},{j},{k,l},{m,n,o}}
How can I join the 4th and 5th sublists based on ...
- 327
5
votes
4
answers
222
views
Replace list of list according to second list
Given
p = {{2, 0}, {3, 0}, {4, 0}, {5, 0}, {8, 0}, {11, 0}}
I want to replace parts according to a second list t1 if the first ...
- 2,030
3
votes
5
answers
213
views
Check how far positions in list to straight line
I have a list of X and Y positions, I do not know what the length of the list.
I want to create a straight line only by use the first and last position in the list.
Then, I want to check how far the ...
- 245
6
votes
7
answers
581
views
How to create a list of lists using Range[]
Given an integer, say 20, how can I create the following irregular list of lists?
lst={5,7,3,5};
Range[#]&/@lst;
generates this:
...
- 4,411
11
votes
11
answers
2k
views
How can I construct this matrix?
How can I construct this matrix by MMA?
$\left(\begin{array}{cccccc}1 & 2 & 3 & \cdots & n-1 & n \\ n & 1 & 2 & \cdots & n-2 & n-1 \\ n-1 & n & 1 & \...
- 1,513
0
votes
0
answers
40
views
Eliminate point of function
So I have a function f(x) and I know that for x=x1 the function goes to infinity. I want to remove this point of the function and a "new" function that interpolates from x1- to x1+ at that ...
5
votes
2
answers
200
views
How can I create a list of not-evenly spaced numbers?
I want to create an array of numbers, but i want them to be more dense according to a sine function (more density of points near $0$, $\pi$, $2\pi$ and so on. I would like something like a ...
- 53
3
votes
3
answers
187
views
how to adjust a replacement list
I have this list of replacement rules:
{{2, 15} -> 1, {2, 2} -> 1, {2, 2} -> 1}
What I need is ...
- 647
3
votes
2
answers
55
views
Drop element of nested list based on position [closed]
I have a nested list, with each list differing in length and made up of strings:
...
- 327
0
votes
0
answers
64
views
How do we define the function near the end of my post?
Suppose I have two sets $F_{1,n}$ and $F_{2,n}$ written as:
...
- 249
3
votes
3
answers
256
views
How can I delete duplicates with Abs?
I have this list with some duplicate elements and I want to delete duplicate ones.
...
- 2,484
3
votes
3
answers
90
views
Get coefficient of a symbolized symbol in a sum that involves other symbolized expressions
My mathematica notebook begins with symbolizing all expressions of the form $x$ subscript an integer, "$x_k$",
...
- 165
0
votes
1
answer
102
views
How can I obtain a list of all consecutive pairs of elements in a list? [duplicate]
For example, given
{a,b,c,d}
I want
{{a,b},{b,c},{c,d}}
What's the best way to do this?
- 359
4
votes
3
answers
189
views
3
votes
5
answers
175
views
How can I get a list of all distinct unordered pairs of numbers in a specific range? [duplicate]
If I do e.g.
Flatten[Outer[List, Range[3], Range[3]], 1]
I get
...
- 359
0
votes
1
answer
105
views
Efficient algorithm for Euclidean distance on a lattice [closed]
I am unable to code the problem in Mathematica. For the problem, please see the attached image. Help in this regard will be greatly appreciated.
The statement of the problem is as follows:
Consider a ...
- 21
5
votes
4
answers
164
views
Need list of unequal lengths to be paired with year
Suppose I have a list of five lists, each with a different number of elements
...
- 649
1
vote
2
answers
67
views
Make a tabbed Workbook of Spreadsheets with TabView (and TableView) [closed]
I'd like to display a 3D table as a tabbed group of 2D tables. As a bonus incorporate TableView to enable editing.
Here is my attempt:
- 1,288
0
votes
1
answer
78
views
Visualization of an iteration scheme in Mathematica
I have a mapping T as attached (here. Now for $x_{0}\in C$ the Mann iteration process read as $x_{n+1}=(1-\alpha_{n})x_{n}+\alpha_{n}Tx_{n}$ n=0,1,2,3,... Now I want to obtain a visualization of the ...
- 161
0
votes
1
answer
85
views
Plotting a cylinder using ListPlot3d
I have a table of dimensions {$\theta$,$z$}= {20,200} that I want to plot as a cylinder instead of a plane.
The code I have is:
...
- 73
6
votes
5
answers
509
views
Need a "rolling" list of lists
I have 32 columns of annual data in varying lengths which I can simulate as follows:
...
- 649
0
votes
1
answer
48
views
How to plot a set-valued mapping graph
I know that if $T$ is a single-valued mapping for example $T(x)=x^{2}$ for all $x\in[0,1]$ then its graph can be plot using
Plot[x^2, {x, 0, 1}]
Is there any way ...
- 161
0
votes
0
answers
73
views
Numerical values of an iterative scheme are different from values in a Paper
I want to solve a pde $y^{\prime\prime}(t)=\frac{3}{2}y(t)^{2}$ with boundary conditions $y(0)=4$ and $y(1)=1$. The exact solution of this problem is $y(t)=\frac{4}{(1+t)^{2}}$. Now I want to solve ...
- 161
1
vote
1
answer
73
views
3
votes
2
answers
104
views
Solve a differential eq with a boundray condtion and plot it
I just wanted to know how to plot this for different value of a,b and f (Table[])?
...
- 391
6
votes
4
answers
403
views
Is there a more elegant solution than f[a, b, Sequence@@#3,...]?
I am trying to construct a list of many possible combinations using Outer and Permutations. Something that looks like that:
<...
- 254
1
vote
0
answers
47
views
How to rescale list to interval $(0,1)$ [closed]
Imagine I have an arbitrary list
l = RandomReal[{-5, 10}, 10]
Out[]= {4.17452, 1.75762, 4.16905, -3.63225, 8.34172, 5.39626, -4.2107, 3.50873, -1.52441, -3.7147}
...
- 4,388
6
votes
4
answers
191
views
Row function to join together binary number elements
I am trying to join entries of binary numbers at the lowest level of a nested list, e.g.
...
- 65
4
votes
5
answers
253
views
How to define functions using a list of polynomials?
I feel stupid for not being able to do this and I think it is just a syntax error.
Let's say i have the following list:
L={x,xy,x^2+y,xyz,x^2}
How do I define 5 ...
- 635
4
votes
2
answers
86
views
Tuples which treats re-ordering as equivalent [duplicate]
I would like to define a new function myTuples, that behaves just like Tuples, except that it treats, as with ...
- 1,249