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

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3answers
176 views

Gather lists according to another list

I have a first list of pairs like this one: ...
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1answer
238 views

GatherBy and two conditions

I have a list of 4 dim points, given by ...
1
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1answer
584 views

How can you convert a matrix back into a list of lists?

It is very simple in Mathematica to convert a list of lists into a matrix: all you need to do is apply the //MatrixForm function to it and voila. Is it possible ...
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1answer
109 views

A list containing zero elements

I have a list containing zero and nonzero elements. How can I throw away zero elements and just keep non zero ones.
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2answers
140 views

Result of NIntegrate ploting to list

I've been working on a project where I need to make two Plots. Those plots are of the form: ...
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3answers
206 views

Distinguishing slots in a function mapping Position across a list

Suppose that I have a list myList that has more than one level. Here is an example of such a "data structure": ...
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2answers
164 views

How to create automatically some matrices for symbolic manipulation?

I want to create in an automatic way some matrices to do symbolic calculations with them. They look like these: $$ \left( \begin{array}{cccc} a & 0 & b & 0 \\ 0 & 1 & 0 & 0 ...
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2answers
151 views

Delete duplicates from hierarchy of lists

Is it possible for Mathematica to compare a number of lists of different sizes, and delete duplicates in a hierarchical manner? For example, given the following lists: ...
1
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3answers
329 views

Matlab-style Find in Mathematica? Value list and Boolean List, how to select values according to the boolean list?

I want to select elements with the true value (Indices list) in the corresponding point to the value list (MCS). Is there anything like Matlab-style Find to get the indices of true values in the ...
1
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4answers
155 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 ...
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3answers
303 views

Creating overlapped block matrices

I'm doing an FEM assignment using Mathematica. (EK1 = {{a11, a12}, {a21, a22}}) // MatrixForm (EK2 = {{b22, b23}, {b32, b33}}) // MatrixForm I don't know how ...
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1answer
197 views

Averaging multiple 2D data sets

I have multiple data sets, each of which is a 2D matrix. I want to construct a new 2D Matrix in which each element is the average of that element for all the original data sets. i.e ...
1
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3answers
190 views

How can I create a new tables out of a table and plot it

I have the following problem. I have a table, call it m, which is labelled by 3 indices (say i,j,k), each of them running from 1 up to 100. I would like to be able to construct a new table which would ...
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1answer
162 views

ReplacePart inside For loop

I am trying to replace the last column of the following expression (mat) by doing ...
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1answer
135 views

How can I make my code simpler?

I want to find similar letters ...
1
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2answers
294 views

How to generate patterns by a list of integers

I have a list of integers {3,4,2,2}. This list will give patterns {x_,_,y_,y_,_,_,z_,z_,w_,w_,x_} and ...
1
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2answers
498 views

Specifying parts from lists for plotting using Show

I have the following data: ...
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2answers
142 views

Return a string from a vector containing a string and a number

I currently have a List of the form, {{String_1, 8.}, {String_2, `101.}, {String_3, 37.}, ..., {String_n, 28.}} Along with another list, ...
1
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1answer
109 views

How can I manipulate with elements inside sublists if sublists of different lenght?

I have some kind of output like this: {{1, 5}, {1, 13}, {1, 5, 25}}. I would like to be able to enter in each sublist and make sums of every two elements in sublists, for example my desired output ...
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2answers
403 views

Operations on sets of sets [duplicate]

Possible Duplicate: How can I remove B -> A from a list if A -> B is in the list? Delete duplicate elements from list Pattern matching deletion of list items How do I delete the ...
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2answers
68 views

Create a table of Mean Values and Standard Deviations from data list

I need to create a table of the Mean Values and Standard Deviations of 18 columns of data from a table. I know how to compute the Mean and Standard Deviation for the different columns, but am unsure ...
1
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1answer
62 views

Incompatibility of Append and NumberForm? [closed]

Consider the code list = {.12, .23, .34}; Append[Round[list, .1], 10] Append[NumberForm[list, 1], 10] The use of Round returns the expected result ...
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1answer
49 views

Collecting specific Lists of data in coordinate form

Note: This might be trivial for many of the users but i am new to mathematica so i don't know!!! Question: Suppose i have three list of data as follows: ...
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4answers
184 views

How to check if all the members of list lies in specific range

I have a list the form: ...
1
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2answers
163 views

Complex numbers from two arrays with Real and Imaginary parts

I have two arrays, containing the real and imaginary parts of a list of complex numbers. Re = {{Re_number1},{Re_number2},...} Im = {Im_number1},{Im_number2},...} ...
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3answers
61 views

Delete permutations of subtables in a table [closed]

I've got a table of tables: $A=\{\{a,b\},\{b,a\},...,\{a,b,c,d,e\},\{e,d,c,a,b\},...\}$. How do I do to remove backward duplicates, or more generally permutations of duplicates in the table? For ...
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2answers
68 views

How to make function accept list of rules as an argument?

Considering the list of rules: r= {"a" -> "1", "b" -> "2", "c" -> 3, d -> 231, "e" -> 1.25}; I want to have a function ...
1
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2answers
124 views

Checker rut for over 7 digit numbers

In Chile the RUT identifier identity, every rut has a check digit module 11 is used, I made this code to 7 digits, but not me 8 digits, a number of 7 digits is the abcdef- form (check digit ) and ...
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2answers
66 views

Evaluate list of functions at a certain point

I have a list of functions (actually they are derivatives) of the type: {D[g[x,y],x],D[g[x,y],y]} I would like to evaluate all of these functions at a point, ...
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1answer
61 views

Nested list element at position specified by a list

I'm trying to avoid constructions like Y[[X[[1]], X[[2]], X[[3]]]]. That is we have a nested list (Y) of depth $n$ and another ...
1
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3answers
149 views

How to ReplaceAll independent of depth?

I have a big list which in principle can be described as this more compact list : ...
1
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2answers
176 views

Replace a value in a nested array

When I run the following, ...
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4answers
128 views

Replacing more than one element from a Sublist

The following expression allows me to extract the value of x and y: ...
1
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1answer
135 views

Check every list element for appearance

I'm used to MATLAB so this might be a stupid question but Mathematica is freaking me out. I have a big matrix with the following format: ...
1
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1answer
82 views

If statement and elements of an imported data

I import a data file: SetDirectory["C:\\Users\\SE7EN\\Desktop\\mathematica\\test"]; dd = Import["data.dat", "Table"] Out[2] = {{1}, {2}, {3}, {4}, {5}, {6}, {7}} ...
1
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1answer
295 views

Compile with array operations

When I use the function f with only the Module ...
1
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1answer
123 views

Need help defining my own rounding function

First of all: I'm a beginner with Mathematica. I'd like to define a function called Rounding which does the following: if for $x = n+a, n \in \mathbb{N}, a\in ...
1
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1answer
501 views

How to convert the following list into a LaTeX table?

How to convert the output of the following code In[43]:= Func[x_]:=Select[Range[x],Total[IntegerDigits[#]^3]==#&]; Func[1000] which is Out[44]= ...
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2answers
266 views

Deleting parts from a nested list

I have a very long nested list. Here is a short example: list = {{1.2, {1, 1, 1, 1}, {2, 2, 2}}, {0.9, {3, 3, 3, 3}, {4, 4, 4}}, {1.4, {4, 4, 4, 4}, {5, 5, 5}}} ...
1
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1answer
125 views

How to apply compiled function on list

Compile function output error: How to apply compiled function on list? ...
1
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3answers
108 views

ArrayRules for a ragged list

Let there be a sample list as , l = {a, {{b, c}}, {d, e}, {f}, {{g, {y}, u, h}, {{{{k, j}}}}},k, {{{{q}, {w}, {r}, {x}}}}}; ArrayRules[l] ArrayRules::rect: ...
1
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2answers
495 views

Swapping elements of list

Say I have a directed graph inputted in the following format in Mathematica: g = {{1, "a", 2}, {2, "b", 1}} I'd like to plot this graph using ...
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1answer
542 views

List plot joined with stair steps instead of diagonal lines

What's a simple way to plot a list of points so that they're joined with stair steps instead of straight lines between the points? I'd imagine something like... ...
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1answer
88 views

Create a new list under conditions from an existing one

I have an external file (data.out) which I read it with Mathematica using data = ReadList["data.out", Number, RecordLists -> True]; This file contains three ...
1
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2answers
172 views

Indicating the probability that a weather datum is above/below some given value on a geographic map

With help of the previous questions here, I am analyzing weather data as daily MeanWindSpeed of some cities with the following code: ...
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1answer
152 views

Statistical analysis of data-list with recurring x-values

I have a list of data as follows with repeated x-values: ...
1
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1answer
67 views

PrependTo fails on a Table of Evaluated funtions

My task is something like this: PrependTo[Evaluate[Table[{x, Sin[x]}, {x, 0.1, 2 \[Pi], 0.1}], {0., 1.}]] where I tried also skipping the ...
1
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3answers
649 views

Ignore missing data while doing a Mean

I want to compute the mean of a list while ignoring missing values, but I don't find a lot of information on how to deal with Missing data in Mathematica. I have a list like : ...
1
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3answers
2k views

How to create functions of arbitrary number of variables? [duplicate]

In the following code what would be the simplest way to generalize it to say some $N_f$ number of $z$ instead of just $z_1$ and $z_2$? ...
1
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3answers
302 views

Replace values of a list containing words and numbers

I'm trying to import some data in a .txt file which contains numbers and words. I import a list which consists of four rows of measured data acquired with an oscilloscope, but the acquisition program ...