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

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1answer
41 views

Setting the value of a list item

I want to set the value of an item in a list. The code that does this has to work regardless of the depth to the list. For instance set the value of r[[1,1,1,....,1,1]] to 9. Lets say the list called ...
0
votes
2answers
62 views

Automatic process to replace missing values, coming from a second matrix

I have a large starting matrix with missing values in different columns. I want to replace this missing data as follow. First I have to check the group (last column in starting matrix) and go to a ...
1
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2answers
57 views

Discard Elements of list with given criteria

I have the following list: ...
1
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2answers
86 views

Count pairs from a List

I have a list of numbers: ...
3
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1answer
66 views

Pareto optimal fronts using internal function?

Reading this question: How do I estimate the Pareto front in my multiobjective optimization problem? I found @Daniel Lichtbau's interesting answer. Yet I don't know how such an "internal function" ...
3
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4answers
168 views

Is there a way to PrependTo or AppendTo while flattening the result in the same step?

arr = {1, 2, 3}; PrependTo[arr, {a, b}] (* {{a, b}, 1, 2, 3} *) But, I want (* {a, b, 1, 2, 3} *) I know I can use ...
4
votes
3answers
131 views

how to apply Alternatives command to delete cases from a list?

I have two lists let say listF = {{7, 2}, {2, 6}, {8, 1}, {1, 7}, {11, 8}, {6, 11}}; and ...
3
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1answer
70 views

Duplicate rows with multiple entries

I have a huge dataset, which looks similar to this: ...
1
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2answers
99 views

Find the minimum element of a row of a matrix and its column index for each row

I am trying to find the minimum value of a row of a matrix and its corresponding column. Please run the code below. OptV is the matrix that I would like to create which must give the output of the ...
15
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3answers
339 views

Find duplicates in list of InfiniteLine

MMA 10 introduced a new function, which can be very convenient: InfiniteLine. Of course, two infinite lines can be described by different arguments: for example ...
0
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4answers
61 views

Matching a Table and a List and building a new Table

I have a Table which includes {Numbers, Probabilities}. For example A= {{1,0.5},{2,0.25}, {3,0.1},{4,0.9}……{100,0.1}}. Put attention that the numbers are 1,2….100 in order. I have a List of random ...
4
votes
2answers
239 views

How do I encode this replacement rule?

I'm pulling a 5x5 array from a larger array. The small sub-array (call it S) can contain any combination of the symbols A, B or 0. What I'd like to do is: if the array contains any matching pairs ...
3
votes
1answer
75 views

What's the easiest way to find the closest point in a list of pairs?

I frequently end up in this situation. I have a solution, but I suspect it's the dumbest way of doing it. Frequently, I'll have a list of pairs, for example: ...
1
vote
1answer
46 views

NRoots Results: From Equations to List of Root Values [closed]

When I use Roots/NRoots, I get a disjunction of conditions as result. The conditions are normally of the type x == value How can I convert this to the list of root values?
2
votes
2answers
66 views

Creating a custom ListPlot of consecutive points

Here comes some sample data ...
6
votes
3answers
291 views

How do I split a list of numbers to monotonic sequences?

Suppose I have: list = {1, 2, 4, 5, 7, 11, 8, 7, 3, 1, -3, -2, 6, 7, 80} And I want to split it to: ...
3
votes
1answer
74 views

Untangling a tangly block of If statements

This is a followup to my previous question: How to simplify block of multiple repetitive If statements? I have another block of If statements, somewhat like the other one I need help simplifying ...
3
votes
3answers
96 views

Extract every nth character from a string

I'm trying to extract every 21st character from this text, s (given below), to create new strings of all 1st characters, 2nd characters, etc. I have already separated the long string into substrings ...
3
votes
3answers
177 views

Drop in nested tables?

I want to drop a specified number of elements from a 'table ...
5
votes
4answers
449 views

How to simplify block of multiple repetitive If statements?

I'm building a boardgame...game in Mathematica. I have the board state represented as a matrix. It's a two player game, and each player (let's call them A & B) only has one type of piece or ...
3
votes
4answers
134 views

Find the length of the intersection of two lists including duplicates

I have 2 Lists. The first one includes all the numbers from 1 to 10. listA={1,2,3,4,5,6,7,8,9,10} The second includes ...
0
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0answers
37 views

Pass List / Vector argument through NDSolve to a function

I am trying to pass vector or list as argument to the function from NDsolve.And I am getting these error. Also I am pretty new to stack overflow. Apology if this a possible duplicate. Here is my code. ...
10
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6answers
577 views
3
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0answers
77 views

Kernel crashes when computing finite difference mixed derivative with respect to y & z but works fine when computing with respect to x & y or x & z?

I am using Mathematica 10.4.0 on Ubuntu 16.04. I am trying to solve a set of differential equations using finite difference method on an NxNxN cubic grid (x, y, z directions). I am getting a weird ...
1
vote
1answer
79 views

Use Map on a Function with two variables

I am new to Mathematica and I would like to find out how to use Map on a function with two parameters such as: ...
4
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3answers
265 views

Enforce monotonicity in a list

Suppose I have a list containing pairs of complex numbers. For example: ...
0
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0answers
61 views
1
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3answers
334 views

Matching the order of a master list of lists from a random list of lists

Using Mathematica 9, I have 2 lists of lists one master with dimensions {300, 6}. The second is some random order but has the same first ...
3
votes
2answers
100 views

How to generate a limited number of tuples of a list and not all?

I have a question for which I couldn't find an answer: how can we generate only a given number of tuples of a list and not all of them? For instance, I want to have only the first two 3-tuples of ...
1
vote
2answers
75 views

How to repeat a set of operations on a single data set?

I am very new to Mathematica and I just couldn't figure out the solution for the following problem. I am trying to iterate the following functions for 10 times. For instance, "a" to "fullData". The ...
1
vote
2answers
101 views

How Do i Extract Only The Coordinates xyz (Number) From This Log file

this Log contains the information of all coordinates of many atoms in a molecular dynamics simulation for a long sequence of time steps, along with some extra information other than the coordinates. ...
3
votes
4answers
253 views

Duplicating and arranging a list

I have a list, {a,b,c,d,...,z} And I want to duplicate that list n times such that, {a,a,a,b,b,b,c,c,c,....z,z,z}. I ...
1
vote
0answers
46 views

List manipulation, averaging over lists and fidelity

I want to create vectors from a function poly[α_, β_, δ_, ϕ1_] were several variables (α, β, δ) are randomly sampled from a unit sphere. Then I want to vary another ...
0
votes
2answers
63 views

Plotting cicle using ListPlot

How can I plot circle plot with ListPlot function or how to organize data to produce circle plot from ListPlot function ? If u do something like this ...
3
votes
1answer
99 views

Replace list element with element from another list based on condition

I Have a list on integers and another list of "duplicates". E.g. start={{3},{1},{2},{4}}; duplicates={{1,4,7},{5,6}} I would like to substitute each element of ...
0
votes
3answers
129 views

Creating Average Grid data from Co-ordinate and value data

Consider a list: ZXV = {{z1, x1, v1}, {z2, x2, v2},........................} where $z$ is Z co-ordinate, $x$ is X co-ordinate, $v$ is the value at the point ...
0
votes
1answer
30 views

Iterating KroneckerProduct[] and returning the result from a function

I am trying to write a function which will take a matrix m and an integer i as inputs. Then it will compute the Kronecker product of m with itself i times and return the result. The code is as ...
1
vote
1answer
82 views

How to determine distance of periodic features in measured dataset

I have a list of x- and y-values associated with a measured height (z-values). Part of the list is plotted below. As you can see, there is a periodic arranged structure, namely a cross. Now I would ...
0
votes
0answers
29 views

factoring a phrase of matrix elements and calculating main eigenvalues

I have a question containg two parts: 1-If we have a matrix as ...
2
votes
3answers
233 views

How to use Select with lists

I am trying to do: Select[minimus[[6]], #1[[2]] < (min[[6]] + emin[[6]]) &] applied to all elements of minimus, ...
6
votes
3answers
305 views

Indicate minimal path sum

Described on the page: http://www.mathblog.dk/project-euler-81-find-the-minimal-path-sum-from-the-top-left-to-the-bottom-right-by-moving-right-and-down/ It is an example of the solution indicated in ...
0
votes
1answer
48 views

How to pad numbers to the border of the Matrix?

I want to pad the numbers,but it throws an error Part::partw,so I use Quiet to suppress this error. ...
3
votes
1answer
69 views

Calling results of applying f to expr inside NestList

Being new to Mathematica, I try to follow the suggestions of using NestList, Map, Table ...
6
votes
1answer
42 views

Heading in Table Form Question

I have: modadd = Table[Mod[i + j, 3], {i, 0, 2}, {j, 0, 2}]; TableForm[modadd, TableHeadings -> {{0, 1, 2}, {0, 1, 2}}] Which produces: How can I put a ...
3
votes
4answers
176 views

select elements in a list

I am new in Wolfram Math and I need a help in making a simple program. Let's suppose we have a list: list = {{1, 11}, {2, 7}, {4, 2}, {7, 9}, {-2, 3}, {-1, 10}}; ...
0
votes
4answers
50 views

insert elements into 2 D array [duplicate]

say I have a 2 dimensionsal array like a={{1,2,3},{4,5,6},{7,8,9}} and a vector like v={10,11,12} I want the result to be ...
4
votes
1answer
103 views

UpTo for negative indices?

The symbol UpTo emerged as a sort of "safe take" in version 10: Take[{1, 2, 3}, UpTo[4]] (* Out: {1, 2, 3} *) But it wasn't ...
2
votes
2answers
80 views

Group Datasets and take minimum/maximum

Good Morning I have the following dataset: And I try to reach this output: key: only one row per key text: join all texts of the rows with the same key (but no duplicates) min: take the lowest ...
7
votes
2answers
96 views

For loop works at top-level but not in a function

Why does this work: For[i = 1, i <= Dimensions[list][[1]], i++, list = Insert[list, i, {i, 3}]] But this doesn't: ...
4
votes
3answers
125 views

Alternative forms to Table for iterating over replacement rules

I have a multivariate polynomial x. I get coefficients of various monomials using CoefficientRules, which returns a list of ...