# Tagged Questions

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

80 views

### Generating a sequence of lists [closed]

I have learnt how to generate a sequence of numbers, but now I come across a question whether it is possible to generate e sequence of lists. Say, I would like to generate {1},{1,2},{1,2,3},...,{1,2,3,...
348 views

### Give a element rank list of a list

SeedRandom[417] list1 = RandomChoice[Range[22, 28], 4] {22, 24, 26, 23} We can get the rank list ...
53 views

### Rearrange the list with some rules

I am trying to solve physic problem on operators which are not commute. However, I am not good at coding, so I am having some problem with Mathematica code. Let's define my list such that ...
63 views

### How to prove that an equation can be divided by any n?

I'm new to Mathematica and came across with the problem. I can't prove that (for example) 2*n is always even no matter what n is....
46 views

### How to graph the max and min values of a sheet?

Hi I just start working in Mathematica version 10.3.1 and I want to graph a sheet of data that I created in Excel (yeah i use Windows). The problem is i have so many data; 200 columns and 50 row of ...
46 views

### Generate list of first 100 prime number? [closed]

I know how to generate a list of prime numbers up to a limit, but how would I generate the first 100 prime numbers in a list?
101 views

### Using “Outer” with “ChineseRemainder”?

I'm looking to build a $7\times3$ matrix using ChineseRemainder. Trying to use ${0,1,2,3,4,5,6} \pmod 7$ and ${3,15,21} \pmod {30}$ so that the first element of ...
70 views

### Calculate Cumulative Mean and Standard Deviation of a list without FOR loops [duplicate]

I have a simple list mylist={x_1,x_2,...,x_N};. Now I want to map a function over this list, e.g. the Mean and StandardDeviation functions, so that it will give me ...
129 views

### How to partition a set with a condition on subsets?

I want to partition a set of $n$ elements into $k$ subsets with a condition For example: partitioning this set {1,...,5} into 3 subsets with this condition: if $|i-j|<d$ then $i$ can't be with $j$ ...
61 views

### Append[] is not working for empty list [duplicate]

I am trying to create an empty list and add an element but the list is not being populated. My code ...
92 views

### How to turn a subroutine into a function?

I've written a subroutine that takes in 6 matrices and after some manipulation returns back 3 new ones. I will use this subroutine fairly often in this notebook so I think it would be easier to turn ...
40 views

### Do[If[ *stuff* ]*arguments*]: Increasing range over which Do iterates changes results of If?

Summary: If I run the same Do[] expression but with the variable(s) over which I am iterating taking on more values (but same increment), an If statement inside the Do[] evaluates as false a few times ...
356 views

### Performance of calculation of means squared displacement

How can I improve the performance of the following code which calculates the mean squared displacement for coordinates stored in data? Here for each time difference ...
41 views

### Help with limiting output

I wrote this program on Mathematica (which I am very new to): ...
486 views

### How do I extract a matrix of only positive numbers given a set of assumptions?

I want to divide a matrix: mat = {{a, 0, -b}, {d, a, 0}, {0, 0, -a}} with the following assumptions: ...
281 views

### Convert elements of list to string

how easily can I convert elements of this list to string. If I have output like this: {{M, 1, 0, 0, 1, 1, 1, 0}, {A, 0, 0, 0}} And I want something like this: <...
77 views

### ListPlot and Show n plots from two lists with large n

For the context, I have been dealing with Random Matrices and Dyson Brownian motion. I have two lists, the first one contains the number of steps, so ...
135 views

MWE: ...
54 views

### Estimating processing time for commands

I am trying to evaluate some equations by using Taylor series of expansion (Series[], ExpandAll[], and Normal[] command), and using n equation and n unknown (Solve). Following is not full command (if ...
134 views

### Replicate sublist in new list

If I have a list of lists $a$ and a list of occurrences of each sublist $n$ a={ {1,1,1}, {2,2,2}, {3,3,3} } n={1,3,2} what is the most efficient way to get the ...
331 views

### How to construct a dataset with lists as columns

So I know this should be pretty easy, but I cannot seem to find a solution anywhere, so thanks in advance for your help: I have three Lists (with numbers as ...
231 views

### How to get this list with a terse method

If I have like {a,b} and I want to get {{a+1,b},{a-1,b},{a,b+1},{a,b-1}} We don't care about the ordering of the list....
187 views

### How to prevent substitution in a part of an expression?

Background: I am trying to write a program that can execute scheme in Mathematica. Now I have things like {"+", 3, {"-", 2, {"'", {"*", 1, 3}}}}. The syntax ...
282 views

### How can one get all possible sublists of a list? [duplicate]

So if list={1,2,3} then output should be {{},{1},{2},{3},{1,2},{2,3},{1,2,3}} or in different order.
91 views

### Lattice model array for distribution of energy [closed]

Edited for clarity I am trying to make a 2-D array constant, lets say 100x100, and perform a function on that. The array would look like ConstantArray=[1,{100,100}]...
57 views

### RSolve - basic question about using rules as functions

I think this is basic question, but I can't find it in Help... (I am begginer :P) I have this expression ...
429 views

### How to fill a grid make its total be largest

I have a blank grid whose dimension is 5*5. I want to fill it with some number using 1, 2, 3 and 4. But in every blank space if you fill 2, its neighbor (include four direction, such as left, right,...
683 views

### Matrix indexed by one number

I'm trying to find a generic way (for arbitrary dimensions) to create a matrix like so a[1] a[2] a[3] a[4] i.e where it is indexed by one number, instead of say ...
157 views

### How do I select strings based on the number they end in?

I have a list of alphanumeric strings, str = {"ANH7134UR1", "ANH7134UL4", "ANH7134UR7", "ANH7134UL17", "ANH7134UR18"}; that I want to assign each string to ...
95 views

### list of all permuations of sublists of a nested list

I've got a certain class of lists with, say, 4 elements, that are lists themselves. E.g. {{1, 2, 3}, {4}, {5, 6}, {7}}. I'd like to find a way to generate a list ...
24 views

### How do I add a finite value to one component of a set of vectors [closed]

I have a set of (x,y) values in some *.csv file, when I open them with Mathematica to plot it some of the plots are shifted so I need to add some finite value to one of the components of every vector. ...
48 views

### List within a Do loop, I can't get any values [duplicate]

I am having the following problem. I am trying to get some values from solving an equation and apply them into a list but in the output I get nothing but the symbol of the variable... The code is as ...
214 views

### Why SetDelayed won't work

I'm trying to do this: Riffle[list = {a, b, c, d, e, f}, tem = RandomInteger[1, Length@list-1]] {a, 0, b, 0, c, 1, d, 0, e, 0, f} But I think this method is ...
200 views

### Creating Nested For Loops for modifying values to append to a List

Basically, the title says it all. I am familiar with python, not so much with mathematica. For the program, I am starting out with three unique lists of values for which I am using a triple nested ...
31 views

### Envelope of a given table (or plot)

Is there any way to construct an envelope of a given table (list) or plot? For example, I have plotted (used ListPlot of txt-file) And then I want to plot the envelope (upper or lower) of this plot ...
27 views

### Find same list elements of two lists [closed]

Example: I have two 2D lists (each list has no duplicate elements): l1 = {{1, 1}, {2, 2}, {3, 3}, {4, 4}}; l2 = {{1, 1}, {3, 3}, {5, 5}}; How can I create a new ...
90 views

### How to ListContourPlot a functional eigenvalue spectrum?

We have a (Hermitian) matrix of some finite dimension (n) whose elements are functions of real variables x and y. We wish to plot contours of the spectrum (level sets of the n real eigenvalues) at ...
76 views

### Function that counts number of consecutive elements after iterator in Table command

I have a 1D Table, something like this, that I want to turn into musical notes: ...
162 views

### Nonzero element positions of a matrix

Let m={{1, 2, 0}, {4, 0, 9}}; I want to find the position of every nonzero element of the above matrix. The code ...
275 views

### How to mesh a region using adaptive cubic elements

Assume a list of {x,y,z} coordinates. The coordinates are arranged in a regular fashion through a fixed raster size (called ...
295 views

### What is the most efficient way to replace items in a list at periodic intervals?

For example, if I want a list of $\phi(n)$ for $1 \leq n \leq 100$ but if $n$ is a multiple of 3 I want to show a 3 instead of $\phi(n)$. I tried ...
42 views

### How to solve from a list

I have this equation: $y(t)=aE^{-bE^{-ct}}$ and I have this list: ...
100 views

### How can I extract the x and y values from a coordinate pair? [closed]

I think the question says it all. I have a coordinate pair, {x,y} and I want to extract x and y for use in further calculations. Can't find anything in the docs about this but it seems like it should ...
55 views

### How to combine 3 list together in a form like this {x,y,z}

have a list like this ...
110 views

### Differentiating between zero and “empty” in lists, and adding them?

(Edit: I mean 'differentiate' as in telling the difference between two things, not as in f'(x) ) I have n series of numbers, let's say two for example, with some "empty" spaces between the numbers, ...
123 views

### Assign a list of sums to indexed variables

I want to generate a list of sums {a, b, c, d, ..., z} and assign them to a list of variables such that ...
69 views

### Import Excel sheet into 3D array, 1st row and column as x- and y-axis

It might be simple, but for me, it took several hours working on, but still cannot figure out. Basically, I'd like to create 3 dimensional list data ({x,y,z}) from excel file, so I can plot them ...
54 views

### positions satisfying pattern and grouped

I have a list of numbers and I am looking for a way to most efficiently find positions of values that satisfy a certain condition and group those positions that are sequential. To illustrate, a simple ...