# Tagged Questions

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

107 views

### Changing the order of elements in a list

I have a list of the form list1 = {1, 3, 4, 2, 5, 6} and I would like to replace each of the elements in the position of represented by the previous number in the ...
54 views

### Convolution with modified indices

I want to perform convolution for a sequence but instead of having the indices cycle from the ends periodically, I want to apply a function, specifically Abs, to ...
164 views

### Selecting points inside a closed curve

Let's create a rather dense grid of initial conditions ...
29 views

### Splitting a list into sublists with different sizes [duplicate]

I have the list {7, 8, 9, 10, 11, 12, 13, 14} and would like to split it into a list of size 2, a list of size 3, and covert the remaining element into singleton ...
46 views

### Mapping AssociationThread over list with repeating keys [closed]

I have two lists. One with the same repeating four keys and the other with unique values. Both are the same length. I want to Associate the first list with the second list. So if that if the 5th ...
197 views

### Selection of points based on position

I have a series of points, for example: points = {{0, 0}, {1, 3}, {2.5, 2.5}, {4, 4}, {6, 6}}; I want to join all points successively unless, for example, the y-...
162 views

In the following example Nearest finds the nearest values between list1 and list2 and ...
95 views

### Group matrix values by column [closed]

Original Question: I have a list {{a, 1}, {b, 3}, {c, 1}, {d, 2}, {e, 3}}. I want to be able to group the the first number in each pair that has the same second ...
125 views

### Calculating density of states from lists of momentum/energy data

I am trying to calculate the density of states for a 2D system given certain band structure data organized in a specific format. Below is an example of my procedure: Beginning with a simple 2 x 2 ...
40 views

### ListPlot[Transpose[{xx,yy}]] returns blank plot [duplicate]

This is complete mystery for me, but I am unable to plot the following data... I have two lists, that I want to ListPlot. The data is created in the following way (I edited the code for more clarity): ...
158 views

### Operation with lists

I have created this code and was wondering if you could suggest a less convoluted way of solving the problem. I have two lists: ...
246 views

### How to double elements of a list given by their positions

Given that I have a list $\{P_0,P_1,P_2,\cdots,P_7\}$, where, $P_i$ is a real number or a list like {x,y}/{x,y,z}. Now I would like to double some elements ...
82 views

### Mapping a simple 2 variable function

Quick Question: What is the best way to map this function so it performs seperately for 102 different values of x? ...
88 views

### best fitting crossing divides region plots with different background colors

We have two lists: ...
102 views

### Hovering over specific coordinates on a picture

I'm working on a small function which can be used so that when the user hovers over certain coordinates in a LocatorPane, these coordinates can be checked against a separate list of coordinates, and ...
194 views

### Finding the most common n-tuples of a list of lists where order does not matter

I am still learning to use Mathematica and I need some help. How could I get the most common pair, and generally the most common n-tuple of a list (row vector) given a list of lists of ...
35 views

### How to create a function similar to MorphologicalComponents?

As everyone knows, MorphologicalComponents can create a list that shows only the difference between morphological clusters. But sometimes we need to find out the ...
71 views

### How to import multiple .m files at once?

For example, I import several files with the following lines: ...
69 views

### Keeping determine digits in Append to process

The end of my code is written as below. Ignoring the inefficient role of Append, I want to have very simple set of values as for example: ...
614 views

### Are there more readable and terse method can get this list

I have a list like following list = {{1, 2, 3, 4, 5}, {6, 7, 8, 9, 10}}; I want get this list by a more better method: I ...
159 views

### Filling between two listplots

I have two lists which are plotted by below simple command ...
64 views

### Combining the entries of two lists [closed]

I have two lists {a, b, c, d, e} and {1, 2, 3, 4, 5}. I want to creat a new list of tuples as follows ...
70 views

### Counting the rows of a list where the order of numbers in the row doesn't matter

I am trying to make a computation with a large set of rows. As a sample, suppose I have a list of numbers with rows and columns like such: ...
62 views

### Need help with making an interactive 3D plot

My main problem is to generate a manipulatable 3D plot, combining three functions and two of those functions depend on another variable Theta (which shall be the manipulateable variable). To explain ...
55 views

### How to generate a random matrix and its average value is a specified value

I want to generate a random matrix whose average value is a specified value,such as 5.5. I found these function here.But I don't know how to use it to do this.I think ...
45 views

### Successive differences of elements in a list with step s apart

I have a list of elements list = {a, b, c, d, e, f, g, h, i, j, k, l, ...} I am trying to get successive differences with step s apart. For example, for $s=3$, I ...
234 views

### Solve and design “water flow”

In some strategy game I play, I'll have to change the terrain to make the water flow in some specific way to fulfill my goal. The water flow changes with terrain so if I can change the terrain wisely ...
82 views

### Updating a nested list using elements from another nested list of the same shape

I am new to Mathematica. A quick question: Given a = {{1,0,0,2},{2,0,1,0}} aR = {{1,0,1,0},{0,1,0,1}} if element in a is ...
244 views

### Unexpected behavior of Sequence — using Sequence to delete parts of an expression

I thought that assigning Sequence[] to the part of an expression was an effective way to remove it. For example, the following code yields {2,3,4,5}: ...
31 views

### Using DatePlus with a list of dates and list of times to add

I have a list of dates such as t2 = {"2016-06-08 05:00:00", "2016-06-08 05:00:00", "2016-06-08 05:00:01"} and a list of offsets (in seconds), such as ...
186 views

### Delete all strings that are prefixes of another string

I have a long list of strings and I'm trying to find a more efficient way of removing those elements that are prefixes of another: ...
46 views

### Showing the numbers greater than 0 in a list [duplicate]

I have an operation that outputs the list ...
57 views

### Working with Real/Imaginary/Modulus parts of an complex Interpolating Function?

From solving n times a numerical (complex) equation, like: ...
58 views

### How do I get a 'list' (or something similar) of functions?

I'm solving an NDSolve equation, like: ...
63 views

### How to merge a ListLogPlot including a discrete set of data points with a LogPlot including some analytical functions?

I have an analytical 1d-function of a variable called $M$ and I have plotted that function using the following code: ...
33 views

### List RGB Values from DominantColors [duplicate]

I have taken an screenshot using the GUIScreenShot function from GUIKit and then evaluated the dominant colours in the image. I ...
82 views

### How to split a SymmetricGroup into some PermutationGroup with smaller GroupOrder

Background I want to get a permutation list, so I use the SymmetricGroup(or use Permutations) to produce it when the ...
31 views

### Use “FindFit” for Multi-variable Polynomial Fit

I'm interested in defining three input vectors: $L=\{L_{1}, \ldots, L_{N} \}$ $W=\{W_{1}, \ldots, W_{N} \}$ $Q=\{Q_{1}, \ldots, Q_{N} \}$ and I'm hoping to be able to input a number for each of ...
159 views

### Picking element from continnuous segment of list according to criteria

From list like: {1, 2, 3, 4, 5, 6, 20, 21, 22, 23, 24, 25, 26, 27, 28, 100, 101, 102, 103, 104} I need to pick position of number that is greatest in continuous ...
93 views

### remove unevaluated cells from table

I have created a table Tv where each row is of the form {x, y, Iv[x,y]} where Iv is some complicated numerical integral and <...
135 views

### How to FoldList over Dataset column without destroying/rebuilding Dataset?

I have a Dataset in the following form but with many more rows and a few other columns. ...
69 views

### generating random algebraic matrix using elementary operations

I generate several algebraic matrices of 12x12 where each element is a combination no repeat of the variables x, y, z and operations +, -, *, /, power, establishment (square root), any of them or any ...
122 views

### How to initialize downvalues from a list?

The For expression below initializes downvalues of a variable a from the values in a list ...
106 views

### Generation of sublists through a single list

I have a list with 25 numbers: list = Range[1, 25] What would be a simple code that could generate 44 new lists with 15 numbers each one of them? Also need to ...
79 views

### Creating a constant-valued matrix having the same dimensions as previously defined matrix

I have the dimensions of a matrix A. I would like to create a matrix B (say, of only 0's) of the same size as A. But A's dimensions are variable. Is there an efficient way using ...
99 views

### How to read a part of huge matrix saved in a TXT file as single expression?

I saved a huge matrix of numbers with dimensions {400, 4001, 2} using Put and got a TXT file formatted in the following way: <...
99 views

### How to add some element in a incomplete list

I have two list to process.Their first of each 2D part increasing monotonically and without repetition. ...
75 views

### Implementing the Cimmino method [closed]

What am I doing wrong? I am trying to implement the Cimmino method, an iterative method for the solution of linear algebraic systems. The final output should be a vector. Here is a description of the ...