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

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0
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0answers
42 views

How to manipulate lists to get only part of the value [duplicate]

This is really a question about manipulating the output of Maximize. I have a function of 2 variables, defined thus: ...
0
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0answers
38 views

How do I plot cities on a Map? [duplicate]

Right now, I have the 20 cities with the most population in the world, given by the lines of code ...
1
vote
2answers
142 views

How do I find the most populous cities in the world?

I am attempting to plot the most populous cities on a world map. Currently, I have the line of code: ...
4
votes
1answer
140 views

What is the equivalent of MATLAB's “timealign” function?

What is the equivalent of MATLAB's "timealign" function? Given two sequences (lists of values) and offsets, timealign will insert 0's into sequences to align them so they have the same number of ...
1
vote
1answer
187 views

Split Lingustic(IPA) at Words Unique Sounds

How might I split a word at each IPA of each unique sound. For example {"pray", "wade"} (* {{"p","r","ˈeɪ"}, {"w","ˈeɪ","d"}} *) ssch answered a question here ...
6
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3answers
169 views

Using PatternTest and/or Condition to detect equal list lengths as well as list element formats

On searching Mathematica.SE for information about overloading functions, I came across several threads about PatternTest and ...
0
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2answers
108 views

Where are the functional programming constructs: `every` and `some`? [duplicate]

Coming from other functional programming environments (e.g., Clojure) I've become accustomed to some functions that I haven't found equivalents for in Mathematica yet. The two I reached for last ...
7
votes
3answers
218 views

How to Flatten Array of Arrays of the highest order in a simple way?

I have a matrix of matrices, given in the following code. I want to flatten the array... ...
11
votes
1answer
173 views

How to find longest monotonic sequence?

I have a list, for example list = {2, 1, 3, 5, 4, 6} How to find longest ascending sequence of this list? There are two meanings of this question: Find the ...
2
votes
5answers
205 views

Treat list as cyclic

I am considering the following case. Say that T={p1,p2,p3} represents a triangle. In addition, I want to parameterize the edges of the triangle ...
2
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1answer
113 views

How to make an efficient difference of sets function?

How to write a nice code that removes all elements from given set A, that occur also in set B? I would like to use DeleteCases[] for this purpose, but have no good ...
0
votes
2answers
156 views

NestWhile application

I have the function which take the last list in nested list, reduce it somehow in several ways so the length of list reduces and output new list wherein input list appended with defferent reduced ...
3
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7answers
333 views

Concise way to generate multiset lists

I wrote the following to generate a multiset with the same number of items over a fixed range: ConstantArray[#, 3]& /@ Range[9] // Flatten ...
0
votes
1answer
126 views

Adding labels on ArrayPlot and coloring rows

I need to add lables on the right from ArrayPlot for each row and color the black square of each row depending on values from two list. Color list has a numbers in some range and should be mapped ...
1
vote
1answer
181 views

Formatting plot of symmetric points differently to asymmetric points

From an array of numbers, I would like to determine (and then colour appropriately) which points are symmetric about a given axis (here, $x = 1/2$), and which are not. For example, form this: ...
4
votes
1answer
197 views

MapThread Alternatives

I want to add two matrices, the first one containing a 2D vector at each position the other one a list of 2D vectors. The 2D vector from the first matrix should be added to each of the 2D vectors at ...
5
votes
4answers
193 views

Group list of lists by Total

I have some list which looks like {{0,1},{4},{0,0,1},{2,0,1},{3,0,0},{3,1},{0,0,0,4}} and I need to group lists with equal sum of elements in ascending order ...
3
votes
2answers
134 views

Write list of polynomials as a matrix of coefficients times a list of monomials

I have the following problem: given a list of polynomials P = {p1, ..., pn} on the variables x[1], ..., x[n], find a list of ...
0
votes
1answer
271 views

How can I combine several 2D-plots to one big 3D plot?

So I've been able to make a list given by list = Table[{xValues, f[xValues, t (*fixed*)]}, {xValues, xmin, xmax}] For example: ...
0
votes
0answers
25 views
0
votes
2answers
123 views

Problem with Select and Pick

I want to filter a data file choosing those elements that match a condition and then plot them. Here is the corresponding code I use: ...
1
vote
4answers
151 views

Can I combine two FoldList into one?

I want get something like this: {{x, x}, {g[x, 1], f[x, 1]}, {g[g[x, 1], 2], f[f[x, 1], 2]}, {g[g[g[x, 1], 2], 3], f[f[f[x, 1], 2], 3]}} one way is ...
18
votes
3answers
729 views

Strip waste braces in nested list

I have nested lists wherein there are a lot of waste levels which looks like l = {{{{{{2, 2}}, 3}, 2, {{2, 33}}, 4, 5}}}; I would like to reduce it to somthing ...
-3
votes
3answers
182 views

Statistical analysis of a data file and its Plot [closed]

As the title says, I have an external data file which contains thousands lines of data. The data file contains eight columns and here is what I would like to plot: Let's assume that the length of the ...
5
votes
5answers
322 views

Counting function, comparing lists

Update I would now like to produce a plot that explores the difference between the squarefree count and the expected mean (without using SquareFreeQ) - something along the lines of: ...
11
votes
11answers
438 views

Replace elements in list not matching elements of another list at the same position

I would like to compare two arrays: m = {a,b,c,d,d,f}; n = {b,b,a,d,d,e}; and get: {0,b,0,d,d,0} I have tried all kinds ...
2
votes
1answer
407 views

Newton-Raphson Method and the Van der Waal Equation Coding question

So I need to find Specific Volumes using the Newton Method from the Van der Waal equation over a change of constant Temperature but variant Pressure. I have been able to make a list of however many ...
1
vote
2answers
102 views

How do I operate on this list elegantly? [duplicate]

calibData = { {200, 10}, {100, 20} } MapAt[N, MapAt[Log10, calibData, {;; , 1}], {;; , 1}] I want to apply a base 10 Log to the first element of each tuple. ...
2
votes
0answers
204 views

Taking real and imaginary parts of indexed functions and speeding up ComplexExpand

I am setting up a large system of ODEs and in order to use the IDA method (which is sig. faster for my system and thus attractive), I must split my equations into real and imaginary parts. I am ...
2
votes
3answers
92 views

List Manipulation matrices

I have the following two lists: List A: ...
5
votes
1answer
131 views

Strange phenomenon with Outer

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6
votes
3answers
223 views

How do I find the number of countries that have a type of industry?

I am trying to find the number of countries that have a certain type of industry. Currently, I have this code: ...
0
votes
4answers
61 views

Don't understand why Do-loop index is not evaluated in Play expression

So here is some weird behavior: When I create a list inside a loop whose elements are Play functions, with arguments that depend on the counter, it is as if the counter is being stored symbolically, ...
0
votes
1answer
149 views

Do loop - variable does not change [duplicate]

I got the follwing code which should add a '1' 100 times to an empty list. plotVals = {} Do[Append[plotVals, 1], {l, 1, Nmax}]; The output is again an empty ...
12
votes
10answers
661 views

Counting sublists containing 0

Given a list: data = {{0, 2}, {0, 0}, {1, 0}, {1, 2}, {2, 3}}. I would like to count the number of sublists which contain zero. ...
9
votes
8answers
579 views

Position of First nonzero number

I want to know is there any one line code to find position of first nonzero number without calculating position of all non zero numbers. For example, ...
1
vote
1answer
266 views

Row-Reduced-Echelon-Form with Equation Parameters for Consistent Systems

I often do row-reduced-echelon-form (RREF) calculations that involve parameters using the RowReduce command. Most times, I want to know which parameters make the system consistent. For example: ...
0
votes
0answers
11 views

Part::partd error on one of two similar lists [duplicate]

I have run into a problem that I can't explain. Here is the code: ...
4
votes
4answers
124 views

Expanding lists with split strings

I've got data of the type: list = {"Class","MW","10 - 11"} which I would like to split into a number of lists based on the number of characters in the second ...
1
vote
1answer
74 views

Exporting data which includes rule as number only and use lhs as label

I use listD1 = Table[FindRoot[(*my eqns depending on k*), {k, conc}] to get a list of solutions for the different values of ...
0
votes
2answers
111 views

how to export nested list

I have a ListPlot where I extract my data again using pts1 = Cases[(*I put my list plot here*), , x_Point :> First@x, Infinity]; which gives me the data as ...
0
votes
2answers
81 views

Generate higher dimensional box vectors

I'd like to generate integer vectors in $\{-M,-M+1,\dots,M\}^n$, where $M$ and $n$ are parameters. For a fixed $n$, say $n=3$ for instance, I only know I can use ...
3
votes
5answers
304 views

Elegantly adding two differently spaced lists of ordered pairs $(x, y)$

Suppose that I have two lists, list1 and list2, of ordered pairs $(x, y)$. The two lists are differently spaced in $x$; some ...
5
votes
2answers
144 views

Ranking a vector containing ties

How can I rank a vector such that the ties are replaced by their middle ranks. For example, {1, 2, 2, 3}. I want to rank this vector but the ties must be replaced ...
0
votes
1answer
96 views

Problem with List Dimension Outer Map [duplicate]

I am currently handling a big list which has the following dimension: {6, 3, 4, 2, 2, 1, 8} where the last number 8 represent a ...
8
votes
1answer
252 views

How can I define a Listable function only apply to a vector?

Consider the function f which should behave as f[{{1, 2}, {3, 4}, {5, 6, 7}}] ...
4
votes
3answers
187 views

Variable partitioning of the data in the form of “list of lists”

I am looking for a way for variable partitioning of the data in the form of a "list of lists" for interpolating the imported data from excel. The data looks like: ...
3
votes
1answer
172 views

Levels and slots

I am struggling with levels and #, if I understand this I think I will be able to grasp the entire concept. ...
8
votes
1answer
160 views

Quickly selecting for points in a set that are within a critical distance of points in another set

Imagine two lists of two-dimensional coordinates: listA = RandomReal[{0,100},{202,2}]; listB = RandomReal[{0,100},{97,2}]; I'm attempting to quickly generate a ...
7
votes
1answer
98 views

Why does Rescale performance vary significantly based on the real number values in a list?

I have a list of the form: testList = Table[{Flatten[RandomReal[{-200, 200}, {1, 2}], 1], RandomReal[{-200, 200}, {69, 2}]}, {i, 1, 100}]; And I would like to ...