# Questions tagged [list-manipulation]

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

548 questions with no upvoted or accepted answers
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97 views

### How to create a listable, memoized function

Suppose I have a known real constant $a$, and I want to calculate $f(n) = \prod_{k=1}^{n}(a-k)$. I know I could memoize this function ...
77 views

### How do I plot multiple lists that were assigned variables created in an iterative fashion from a larger matrix?

I have a 70x16 array of values ("DATA22K") imported from a .xls spreadsheet, with the x-values (time) being column 1, and the fluorescence intensities of 15 samples (over time) being columns 2 thru 16....
280 views

### Limit of a List

Is it possible to take the limit of a list instead of using the Limit method? I'll try to explain what I mean. I am generating a list of numbers that converge to some number. The generated numbers ...
88 views

### Distance between points in a 3d data given a direction

I'm trying to group the points in a given direction as a function of the distance between each point, and then apply a function to the third coordinate. But I can only get these two directions, using ... 55 views

### Exporting a large number of image variables in mathematical 11

I used the following code to import a large number of tiff images into notebook. ...
153 views

### How to draw local trend lines and divergence lines?

Here are two lists as lstClose and lstCCI, the lstCCI is computed from ...
172 views

### Designing a Manipulate Block

I am trying to create a Manipulate block which contains tabels, graphs and explanations. In the first row I want to add some tables and explanations, but sometimes the tabels are cut. For doing this I ...
65 views

### How to iteratively change RGB style in Show[Table[ListPlot[...]]] and create a Legend?

I am trying to plot the outputs of a ListPlot with different colors for the 3 different cases and create a legend. I have tried with a simple For cycle, but then ...
249 views

### A Table of Sums, but faster

I'm trying to calculate the following lists a_j and b_j from some predefined values. (this is not code, it's just supposed to be a mathematical expression) ...
121 views

### Output in table form with 10 digit precision

I am trying to generate tabular output for the following code. I am trying to solve transcendental equation and I am using FindRoot to solve this equation. ...
210 views

### Export list and NumberForm

Say I have the following code ...
139 views

### Extracting Data from For Loop

I want to add phases in for loop and after adding a new phase I want to export this data? How can I do this? Can you show me where I do wrong? ...
80 views

### An array of function values over the region $\{(x,y): -1\le x,y\le 1\}$

I had one of my colleague instructors ask me how to evaluate the function $f(x,y)=x^2+2y^2-x$ over a few points in the region $\{(x,y): -1\le x,y\le 1\}$ and display them in table form with headings ...
146 views

### ArrayPlot with blended color

I have two ArrayPlot and I would like to show using one legend. The flowing is works. My question is can we use ...
37 views

### Selecting few arrays from a list and displaying their content

I am using FeynHiggs package on Mathematica 11 to calculate fermion masses in MSSM. Function FHGetPara[] returns a list that ...
78 views

### How to build a list nesting if statements

Let's say I have a function f[i_,j_] $i$ and $j$ take integer values. $i$ can range from 1 to 20. For any given integer i (between 1 and 20), as you increase $j$ ...
48 views

### Inconsistencies in the Timing of evaluation of equal-sized lists

If I read data from a data file and manipulate the list and do some calculations. The resulting is a list of dimensions: Dimensions@δx {16, 59210} Then I create ...
59 views

### built-in functions with one argument

I want to find the (NumericFunction) built-in functions that take exactly one document. ...
396 views

### ParallelTable and Table give different results

I am trying to parallelize a table operation, but I find that the table is not the same with and without the parallel function. I have looked at this question, but I cannot transfer it to my own ...
61 views

### Sequentially generate elements of Mathematica-generated list

Mathematica has a number of built-in functions that generate lists, such as Permutations. Is there is universal way to generate only portions of these lists at a ...
40 views

### ComposeList not building the expected list of compositions

Starting with: ...
99 views

### FindRoot inside Flatten Table

I want to evaluate a function that depends on parameters and on another function that, by its turn, also depend on the same parameters. For example, let's say I have f(x(a,b);a,b), where a and b are ...
97 views

### Roots of cubic polynomial when a coefficient is an infinite list

I would like to have an expression of the roots of a cubic equation of the type $x^3+ \gamma x^2 + kx = f(k)$ where $\gamma \in [0,1]$, $k$ is an integer and where $f(k) = \{|k|,|k|+2, |k|+4,...\}$. I ...
88 views

### Correct Loop to use for Repeated Applications of /. Rule?

I have a $n\times n$ table (matrix). Let's just say $n=2$ but it is arbitrary. It has a smattering of indexed coefficients, see below for example. ...
172 views

### Tuples with restrictions

SHORT VERSION Given 2t Ranges, each of length len, what is the fastest way of finding the ...
57 views

### Formatting Infinities in a Table

What is the correct method to replace all types of infinity e.g. ComplexInfinity that are present in a Flatten ...
51 views

### output has a term uncomputed

I am trying to sum the all numbers in each row of matrix and divide them by the max value of the row. My output has the following terms that has not been computed yet (example, the second element in ...
330 views

### Easier way to input Dynamic matrix?

I've only been using MMA for a month, and I'm working on making interactive Linear Algebra examples that will be used online for students. Right now, for inputting numbers into a matrix, I've been ...
222 views

### Henon Map Equation Trekker

I am trying to make an Equation Trekker for the Henon map in the following way: ...
516 views

### Use If condition with ListPlot

Here is my code to use If condition with PLot: ...
204 views

### Make smooth plot from data

After some awesome tips from @qwerty I still have some doubts. As I said, I'd Like to make a smooth function with some other colors, I plot the graph, there is a lot of data. The situation is this: I ...
100 views

### Can't operate on vector within a list of rules

I'm trying to set up a list of rules which includes the following: ...
82 views

### Time needed to solve NIntegrate is much longer than what I was expecting

I'm trying to do the following list: tablevdip = ParallelTable[{x, y, Vdip[x, y, 6]}, {x, -1, 1, .5}, {y, -1, 1, .5}];] with ...
171 views

### Nestlist inside Compile

My question is a continuation of question1 and question2, but I think it may be considered as a self-contained one. I am interested to make the following code faster ...
253 views

### Inverse Superposition

There are 4 tables that, I have written them as bellow: (m, n, s, and r are orthogonal basis. r.r=n.n=m.m=s.s=1, and m.n=n.r=...=0). a's, b's, c's and d's are coefficients and are numeric values. <...
133 views

### Equation Autogeneration

The following is resubmitted as edit here to reflect suggested formatting corrections so indentations separate the lines neatly. I also fixed the unknown D variable which I actually meant to state as ...
138 views

### How to efficiently find period orbits in a series defined by recurrence relation?

I have a series defined as $z_{n+1} = z_n^2 + c$, which is the series for the Mandelbrot set. I have defined it, in order to plot the set, as ...
99 views

### Matrix iteration failing after second step

I am calculating 11x6 matrix using different logics as in below code. Problem is in Do loop in below code where I have two different criteria to update matrix "fd". I am expecting logic in IF which ...
75 views

### How can I get the covariance result cumulatively?

I am trying to derive the covariance results for a $n \times 4$ matrix where $n$ is an arbitrary number. I am trying to derive the covariance for each row cumulatively. For example, I am trying to ...
80 views

### Improve performance of processing transactions in a large file

I want to work with a table which has 296,705 transactionslines and 172,147 transactions. ...
246 views

### Improving the speed of evaluating Table with nested functions

I am a Mathematica novice working with a stack of 1024 x 1024 WatershedComponents (or MorphologicalComponents) label matrices ...
104 views

### How to compute variances from a matrix/table

I have created a matrix/table with an imported dataset. I want to know what the variance is for 3 values at a time but across 68 columns. I would like to do this in an automated way rather than 1 set ...
121 views

### Optimization of vector manipulation

I'm trying to implement an upwind scheme for solving transport equation (at first, I work with no right hand side and the simpliest case possible - velocity is constant, initial data is smooth, etc). ...
62 views

### How to find all functions that accept level specifications as an argument?

How can I find a list of every function that takes a level specification as an argument?
191 views

### Why can”t I get a smooth curve?

I used "Table" to calculate and plot the following complicated function. First, we choose an initial value for $G$ and other parameters, but at later times $G$ changes with function $I_a$. ...
82 views

### Picking phase terms out of an exponential

I need to pick out certain terms from a sum of exponentials. For example, in the sum below: \$a + b e^{i\,\Delta\,t} + c e^{ i( (\Delta + \Omega) t + \varphi_{0})} + \Delta e^{i\,\delta\,t + \varphi_{...
108 views

### How to construct a matrix composed of a subset of column of multiple .cvs files

Suppose I have a lot of .cvs files in a directory. All have the same structure and the first column is a column of dates --- their length is not necessarily equal. For instance, say I have two files ...