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

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19
votes
5answers
896 views

Map-Thread-Through-Apply a list of functions onto a list of (lists of) values

I have a list of functions: fns = {f, g, h} and a list of triples: ...
0
votes
1answer
37 views

ListPlot problem

I have the following example: x = {1, 2, 3, 4} y = {{1, 2, 3, 4}, {2, 3, 4, 5}, {3, 4, 5, 6}, {4, 5, 6, 7}} Now I can plot: ...
4
votes
1answer
31 views

Built-in (or Terse) Method to Combine and Transpose Datasets

From some calculations I have ended with Datasets of the form: ...
0
votes
1answer
34 views

Export list in 4 columns without curly brackets

I have generated the following list: http://pastebin.com/vmtRrfcD (updated) The dimension of the list is ...
4
votes
3answers
121 views

Extracting *firstly roots* from some lists to plot their pairs values

I have two different lists as list1 and list2. Their ListPlot3D of them are: and As shown in these plots, there are some points of which ...
-3
votes
0answers
46 views

Can I use function to generate List from another?

Suppose we got a 3 dimensional List M(x,y,z),xyz indicates the dimension number. Can I get a new List use just function like NewList=M(x,y,z+1)/M(x,y-1,z)? M here would like {{{a[1, 1, 1], a[1, 1, ...
0
votes
2answers
97 views

Uniting lists of lists

Here's what I'm trying to do. First a simple example: ...
0
votes
0answers
30 views

A function that takes in an array and returns an array (or lists)

So I have function f[x_] := c.x - Total[Log[b - A.x]] where the variables have dimension c is 1x100, b is 500x1, A is 500x100, and x is 100x1. My goal is to get the ...
0
votes
1answer
29 views

Struggling to Apply “Differences” [duplicate]

It looks like the following code should work, and allow it spits out error messages saying I have too many arguments, the code spit out after the error message looks like exactly what I want to ...
2
votes
1answer
73 views

Apply function to a part of a list [on hold]

Let's say I have some data: data={{a1,b1},{a2,b2},{a3,b3},{a4,b4},...} and I would like to apply the function: f1[x_]=x*5 to ...
5
votes
2answers
101 views

Threading sublists on list

Suppose I have a list of the form: list = {a, b, {c, d}, f, {g, h}} i.e. an element of the list could be another list. I want to 'thread' each element of the ...
0
votes
1answer
43 views

Manipulation of imported Datafile

Since I am solving a differential equation in a for loop with NDSolve ...
2
votes
2answers
40 views
3
votes
1answer
119 views

Plotting a table with many y values

I'm trying to plot a bifurcation map for a Lorenz System. I have a function (called estables in the code that follows) which, for a certain value r, returns the ...
0
votes
0answers
44 views

How to apply a function to a list, being able to use a list index inside of the function? [on hold]

In the documentaion I find things like: M = {a, b, c}; kappa[x_, y_, z_] := x PauliMatrix[1] + y PauliMatrix[2] + z PauliMatrix[3] kappa @@ M // MatrixForm But ...
1
vote
1answer
182 views

Finding Coordinates of a Peak on a Plot

I have plotted a graph from a CSV file which consists of two columns of data Time and Intensity. I simply want to find the time where the intensity is largest. This code: ...
6
votes
1answer
104 views

Filters on image vs data

I was using GaussianFilter and realized that applying it to an array yields a different result from applying it to an image. For instance: ...
-1
votes
0answers
30 views

Insert several sequential alphanumeric characters pdf [closed]

As I can make it through "this" directory 1 to "this" in the directory 2 and so on for 50 pdf, Deputy sample directory Example
3
votes
3answers
167 views

Looking for a better way to delete an arbitrary list of rows from a matrix

Delete is not suitable to delete the rows of a matrix, as illustrated below: ...
1
vote
3answers
122 views

Basic Programming in Mathematica - How to build a loop [closed]

I want to build a loop with the following rules: I have a list a={5,7,8,9,5,6,8,6,7,8}. I want to print the mean of the first two ...
16
votes
4answers
479 views

How to enumerate all possible binary associations?

Suppose I have a list of symbols like: {a,b,c,d} I would like to enumerate all possible binary associations (combining symbols and/or sublists pairwise): ...
0
votes
0answers
30 views

Find the variables in a set of linear equations [closed]

Suppose I have a set of linear polynomials with integer coefficients, how could I extract the list of variables? Say given the following ...
12
votes
3answers
218 views

Exclude overlapping lists while keeping disjoint- and sub-lists?

Consider a function f[l1_List,l2_List] which is given lists of integers. Whenever two of the lists contain completely disjoint sets of integers OR one of the lists ...
4
votes
2answers
129 views

Select non-zero elements [duplicate]

I have a function that generates a list of numbers and variables . e.g. F[w]= {wx, wy, 5, 0} I want to select all non-zero elements i.e. ...
2
votes
1answer
9k views

Table - find index of the maximum element [duplicate]

Let's suppose that I have table t = {1.23, 3.4, 10, 34, 1.78, 0.98, 12.56}. To take the biggest element I can use Max[t] ...
2
votes
3answers
143 views

What is an efficient way to pick out consecutive, same first-letter words from a list?

Taking a list of words, I'd like to pick out consecutive words that start with the same letter. The output should be a list of these pairs. The following is relatively slow: ...
0
votes
1answer
48 views

How to get a speicifc element from unknown number of lists?

I have a mathematica function that returns a list of the form: ...
0
votes
2answers
77 views

Fitting a Gaussian model to specific section of my list?

I'm analysing some Decay sepctrums for a Nuclear Physics project. I need to fit a gaussian model to a specific X-Ray peak to determine the centroid so I can get a good channel-energy calibration. ...
0
votes
0answers
34 views

Append value to list automatically when day changes

I am trying to append values to a list automatically when the day changes, is there a way to do that on mathematica?
8
votes
3answers
269 views

Creating new List by comparing 2 lists elements

Suppose I have two Lists (Not equal length). Both contain random numbers between 0 to 5000 (or another max limit): ...
4
votes
2answers
206 views

Flip sign of one variable in list

I have this list of x, y-pairs l={{x1, y1}, {x2, y2}, ...}. Now I need to flip the sign of the y values only before plotting. What is the easiest way to do this ...
2
votes
1answer
46 views

Extract part of list by reading it in a cyclic manner

I have trouble extracting part of a list in a specific order, say, increasingly in a cyclic manner. For example, I have the following list list={0,10,6,-5,-10} ...
2
votes
1answer
65 views

Why does `Position` by default return a list of lists of positions instead of a simple list of positions?

Position[{1,2,3,4,2,3,4,5},2] (* Output: {{2},{5}} *) Why does Position work this way? I understand this form might be ...
2
votes
7answers
329 views

How to repeat a matrix on it's side?

I have the following matrix in Mathematica: mat = {{0,0,1,1}, {0,1,0,1}} I want to repeat this matrix N number of times on the side. For example if N = 3 then ...
0
votes
0answers
19 views

General question about solving a large set of linear equations efficiently

In my research, I got a large set of linear equations, about 10 000 equations with more than 10 000 variables. It is not efficient to use "Solve", so does anyone know any way to solve the equations in ...
2
votes
3answers
147 views

Selecting lists from lists of lists

I have the following list: points = Tuples[Range[0, 1.25, 0.25], 9] I would like to select only those lists who have the following properties, naming the ...
0
votes
5answers
156 views

How to expand a MxM matrix with replicates of itself and drop some of the rows and cols periodically?

How can I expand a 2d-matrix with dimensions x,x (e.g. mat = {{ 1, 2 }, { 3, 4 }}) with replicates of mat into ...
7
votes
1answer
103 views

Generalizing LongestCommonSequence to 3 or more arguments?

The function LongestCommonSequence finds a longest common subsequence between 2 lists. Apparently, this built-in function does not accept more than 2 arguments. How ...
4
votes
6answers
424 views

Easiest way to extract the coefficient of a polynomial

For a term in a polynomial, say 387 a1^4 a2^3 x^3 y^7 z^100 w^364 What is the most efficient way to extract the coefficient of this term, i.e. 387?
3
votes
2answers
119 views

Creating a Random list with constraints

I need something similar to the List below, but not totally random and values within each individual column and row remaining the same: ...
3
votes
1answer
75 views

List of first elements

I have a list whose elements are (symbol or list) and I would like to replace the inner lists by their first elements. I do this ...
3
votes
2answers
66 views
3
votes
3answers
227 views

How to switch between a binary number as String and a as a list of digits?

I was trying with String Functions and I viewing any posts and have no results I want to know 1.- From cromo33 = Table[RandomInteger[], {i, 1, 33}] cromo33 ...
0
votes
1answer
24 views

Question about loading data by skipping

. It is often important to take data and measurements and give them a name which has a number, and manipulate them in a for loop fashion to manipulate a large data base efficently. The loop above ...
3
votes
1answer
49 views

Returning maxima of multiple sets

I am trying to prove a conjecture which involves the SetParitions[n] function (which requires the Combinatorica package). This function returns a list of all the set partitions of n. I'd like to take ...