# Tagged Questions

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

85 views

### How to determine distance of periodic features in measured dataset

I have a list of x- and y-values associated with a measured height (z-values). Part of the list is plotted below. As you can see, there is a periodic arranged structure, namely a cross. Now I would ...
29 views

### factoring a phrase of matrix elements and calculating main eigenvalues

I have a question containg two parts: 1-If we have a matrix as ...
236 views

### How to use Select with lists

I am trying to do: Select[minimus[[6]], #1[[2]] < (min[[6]] + emin[[6]]) &] applied to all elements of minimus, ...
328 views

### Indicate minimal path sum

Described on the page: http://www.mathblog.dk/project-euler-81-find-the-minimal-path-sum-from-the-top-left-to-the-bottom-right-by-moving-right-and-down/ It is an example of the solution indicated in ...
49 views

### How to pad numbers to the border of the Matrix?

I want to pad the numbers,but it throws an error Part::partw,so I use Quiet to suppress this error. ...
70 views

### Calling results of applying f to expr inside NestList

Being new to Mathematica, I try to follow the suggestions of using NestList, Map, Table ...
44 views

### Heading in Table Form Question

I have: modadd = Table[Mod[i + j, 3], {i, 0, 2}, {j, 0, 2}]; TableForm[modadd, TableHeadings -> {{0, 1, 2}, {0, 1, 2}}] Which produces: How can I put a ...
182 views

### select elements in a list

I am new in Wolfram Math and I need a help in making a simple program. Let's suppose we have a list: list = {{1, 11}, {2, 7}, {4, 2}, {7, 9}, {-2, 3}, {-1, 10}}; ...
51 views

### insert elements into 2 D array [duplicate]

say I have a 2 dimensionsal array like a={{1,2,3},{4,5,6},{7,8,9}} and a vector like v={10,11,12} I want the result to be ...
105 views

### UpTo for negative indices?

The symbol UpTo emerged as a sort of "safe take" in version 10: Take[{1, 2, 3}, UpTo[4]] (* Out: {1, 2, 3} *) But it wasn't ...
83 views

### Group Datasets and take minimum/maximum

Good Morning I have the following dataset: And I try to reach this output: key: only one row per key text: join all texts of the rows with the same key (but no duplicates) min: take the lowest ...
98 views

### For loop works at top-level but not in a function

Why does this work: For[i = 1, i <= Dimensions[list][[1]], i++, list = Insert[list, i, {i, 3}]] But this doesn't: ...
135 views

### Alternative forms to Table for iterating over replacement rules

I have a multivariate polynomial x. I get coefficients of various monomials using CoefficientRules, which returns a list of ...
199 views

### Fast implementation of Metropolis-Hastings update with multiple sets

This is an optimisation question rather than something I am unable to do. I have a naive, primitive working version of the code (I submit it below) but I am trying to make it work faster. I am asking ...
78 views

### Create table of elements which belongs to specific sets

I would like to produce elements (preferably by Table or For-If commands) that they belong to specific sets. For example I want to write positive integers from 1 to 100 such that they are $2 \pmod 3$, ...
265 views

### Minimize sum of array elements subject to conditions

I have array where each point at different times are shown parameters ...
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 ...
54 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 ...
357 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: ...
283 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: <...
78 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: ...
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....
188 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 ...