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

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1
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1answer
50 views

Plotting a two lists generated after running a for loop [on hold]

So i had to model and solve a harmonic oscillator, being driven by a random driving force. I have managed to finish that and my program is: ...
2
votes
2answers
35 views

Function for generically controlling 'Manipulate' parameters

I want to use a generic function to generate controls in manipulate, which looks like this: ...
3
votes
1answer
151 views

Finding pairs where the intersection of them is empty set from a nested list

It would be better to give an example first. Suppose I have a nested list of the form list = {{ 1,2,3,6}, { 3,6,10,20}, { 4,7,11}, { 10,20}}; where each element ...
5
votes
3answers
167 views

Finding largest Range in a list

In a list of positive integers, I would like to find the largest n such that Range[n] is a subset of the list. So for example ...
3
votes
1answer
87 views

How can I create a set (list) provide a kind of rule/algorithm?

Example: S = {r ∈ Q : r² < 2} Let S be the set of all rational numbers whose squares are less than 2. It follows that 1 ∈ S, 4/3 ∈ S, but 3/2 doesn't ∈ S because 9/4 ≥ 2. Thank you.
10
votes
6answers
297 views

Split according to List and apply rule

I have a list which looks some thing like this {a1, a2, a3, a4, a5, a6, a7, a8, a9, a10} Now I want to split it according to lengths ...
8
votes
7answers
551 views

Brackets around each item in matrix

I have a matrix where every item in the matrix has its own brackets that I do not want. How can I remove the brackets around each item?
4
votes
1answer
75 views

Is it possible to recover the efficiency of ListConvolve when generalizing the convolution?

I've noticed that, while ListConvolve is very fast, it becomes much slower when you use anything but the standard Times,Plus as ...
2
votes
1answer
43 views

Reading an exported List

I have exported a list of 2d coordinates as a List: Export["F:\\coordinates.dat", coordinates, "List"]; You can access the ...
14
votes
3answers
342 views

How to group and join points

It seems there are many similar questions on Mathematica.SE, but none addresses (to the best of google) exactly my problem. I have the following data: ...
3
votes
2answers
73 views
4
votes
1answer
88 views

Table with List iterator return unpacked list

Table support list as iterator, for example list1=Table[w, {w, Range[1., 10., 0.01]}]; We can confirm that list1 is packed ...
4
votes
1answer
74 views
2
votes
1answer
136 views

Why is there a difference when formulating patterns for Select and FirstPosition?

Select[{1, 2, 4, 7, 6, 2}, # > 2 &] Gives {4, 7, 6}. OK! So one should think that the following would work: ...
7
votes
2answers
286 views

Why doesn't this pattern work?

I want the in-built function Count to count the elements in a list which are greater than a value. Example: ...
1
vote
3answers
118 views

Compute intermediate totals using Select and Plus in a list

I have to total per year of weekly results of a function which are in a table with 3 rows: one with the result of the function, one with the week number and one with the year number. I am almost sure ...
3
votes
1answer
116 views

Efficiently generating tuples with Outer

I'm trying to efficiently generate tuples of lists of objects that satisfy a given criterion. The similar questions that I have found on this website end up finding a specific workaround for the given ...
2
votes
1answer
89 views

Automatic text-wrapping in labels in `TimelinePlot`

Part-related to this question and part-related to this one, I would like to make use of the new features of TimelinePlot in 10.3, but would like to incorporate some ...
2
votes
0answers
43 views

How can I convert some data in TableForm to a list form like as {{0,1}, {1,2},{…,…},…,{m,n}}? [on hold]

How can I convert some data in TableForm to a list form like as So, I have some data there I take from laboratory, but the data has a TableForm 0.0 0.2174 1e-06 0.2178 2e-06 0.2172 3e-06 ...
18
votes
5answers
443 views

Partitioning a list when the cumulative sum exceeds 1

I have a long list of say 1 million Uniform(0,1) random numbers, such as: dat = {0.71, 0.685, 0.16, 0.82, 0.73, 0.44, 0.89, 0.02, 0.47, 0.65} I want to ...
0
votes
1answer
46 views

How to make an empty list inside a module program? It consatly spews errors [duplicate]

Okay, so, I'm trying to write a program within the module. It goes like this: create empty list, join it with a sample from a certain set called MyList, and then repeat it certain number of times. ...
3
votes
0answers
50 views

Weird behaviour for a vector InterpolatingFunction inside an NDSolve

I have run into some weird behaviour on the part of NDSolve which I find pretty bizarre and which I would like to understand better. Suppose, for the sake of ...
6
votes
2answers
846 views

How to create a histogram of annual events, such as cherry blossom time

I have calculated blooming and ripening times for a specific variety of plant, based on actual temperature data from over 40 years. I would like to create two histograms on a single axis; one for ...
7
votes
1answer
117 views

Add terms to nested list

Suppose I have a nested list of the following: list={{1,2},{5,8},{4,1}...} I would like to add a number to each first term of the list. The output would be ...
1
vote
1answer
57 views

How to refer a number in a list with two columns, first one is a number and the second one is empty? [closed]

Let's say, I have defined a list as list = {{-31, -31}, {52, }, {34, -11}, {-38, }, {78, -44}, {-36,14}, {-9, 98}, {33, 6}, {82, 99}, {-85, -10}} As you can see, ...
3
votes
1answer
71 views

Calculating products of given length of two matrices

I have the following problem to solve. Let us have two given square matrices $A$ and $B$ of the same size and a positive integer $n$. I would like to produce all products of length at most $n$ of ...
0
votes
0answers
33 views
1
vote
1answer
33 views

Reverse element in nested list [closed]

Suppose I have a list as the following: list={{1,9},{7,0},{8,6}....} How can I reverse the element in such way that the output would be the following: ...
8
votes
6answers
2k views

Check if two lists are equal in any order

Suppose I have two lists, how can I efficiently check if the two lists are identical up to permutations of the elements? For example I would like the function to output: ...
0
votes
0answers
30 views

Group nth Subelement of Nested List [closed]

I'm trying to group the nth subelements of a nested list together. The input would look something like in={ {a,b,c,d}, {e,f,g,h}, {i,j,k,l} } and the ...
2
votes
0answers
44 views

Transposing a table [closed]

I created this table so that it is a collection of 5 different functions that I need. It outputs the values that I want, however, I cannot figure out how to get the orientation right. I would like to ...
1
vote
2answers
45 views

Create an indexed list of functions [duplicate]

I am trying to use a Table to create the following object: {f[#,1]&,f[#,2],f[#,3]} The obvious doesn't work, ...
1
vote
1answer
30 views

How to create sublists of consecutive elements? [duplicate]

I have a list of elements, for example: myList={5, 12, 16, 18, 19, 24, 28, 29, 31, 32, 35, 42, 43, 47, 50, 53, 60, 61, 62, 64, 79, 82, 84, 92, 105, 128, 136, 153, 154, 155, 156, 158, 159, 160, 164} ...
7
votes
2answers
190 views

How to implement JoinTo efficiently?

AppendTo is not efficient so I'm not quite sure of the best way to implement its analogue for joining (e.g. in python this would be extend function). So how can this be improved: ...
0
votes
1answer
44 views

How to apply a user-defined function to a list [closed]

I'm using Wolfram | Alpha Pro; I have a function f[n] = 351n^(-0.7); How do I apply it to each element of a list like {2, 9, 22}? f/@{2, 9, 22} just results in ...
14
votes
3answers
427 views

Generating Tuples with restrictions

I am interested in a certain subset of all tuples. Generating all with Tuples and then filtering is wasteful, and will "blow up" very quickly. For a concrete ...
4
votes
1answer
137 views

How do I disable that Mathematica orders terms in lexicographic order?

I have matrices with entries where the order of the entries is important. Unfortunately Mathematica resorts terms in products in a lexicographic order. For example, ...
5
votes
2answers
241 views

Max of imported numerical data will not work

I loaded a list with 400,000 values from a file. The list was loaded correctly as I can get it's length (by Length[]) and I can also plot it. Why can't I get the Max or Min of this list though? When ...
4
votes
0answers
57 views

Create an adequate 'training set' to train a ClassifierFunction which performs the role of the built-in `SubsetQ`

I am trying to "grow" my own SubsetQ function using Machine Learning methods. My cSubsetQ when given two lists (listA and ...
5
votes
3answers
165 views

How to replace an element in a list with an element in another list with matching indices

I have a list like this l = {1 + 2*s, 2 + 3*s, 4 + 1*s}, and I have calculated s = {1, 2, 3}. I need to replace ...
1
vote
0answers
21 views

Append in For loop doesn't work [duplicate]

I want to simulate a projectile motion under the effect of air resistance by using Append in a For loop, but there appeared to be no changes in the two lists I defined for storing horizontal and ...
2
votes
1answer
32 views

Encoding/Decoding matrices as integers, integers as matrices [closed]

I want to convert large binary matrices of m x n dimensions into integers, and then to convert these integers to the original matrices. I attempted the following: ...
0
votes
0answers
29 views

DeleteDuplicate from a list with {x == y, y == x} -> {x == y}; [duplicate]

How can I tell Mathematica that it should delete equal elements from a list, which aren't in the same order. For example list={x == y, y == x} ; should become ...
9
votes
2answers
157 views

Position with test for list of lists [duplicate]

Why do I get this error message? It seems to me that the level specification should have done the job. ...
1
vote
1answer
63 views

Monitoring a matrix with changeable elements as Manipulate in plotting [closed]

If we remember, Mathematica has an ability to show a Psudo-window of plots for monitoring the effects of some changeable parameters in the functions. For example ...
9
votes
3answers
384 views

Generalization to AllTrue, AnyTrue and NoneTrue

I am wondering if there is a natural Mathematica way to generalize those functions. To be specific, All three functions AllTrue, ...
10
votes
4answers
262 views

How to make FlattenAt work with Span?

This works: MapAt[h, {a, {b, c}, {d, e}, {f}}, 2 ;; 3] (* {a, h[{b, c}], h[{d, e}], {f}} *) but this doesn't: ...
2
votes
4answers
55 views

Partition list into sublists of decreasing length [duplicate]

For example, I would like to partition {1,2,3,4,5} into {1} {1,2} {1,2,3} {1,2,3,4} {1,2,3,4,5} with just one line of code. ...