Questions on the use of the Table[] command and other functionality related to lists. Use [tag:matrix] for matrix algebra and related methods, and [tag:list-manipulation] for questions about transforming or operating on existing lists.

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8
votes
1answer
202 views

Export bug in combination with ParallelTable?

I am programming with Mathematica 10.3.1.0 on Windows 10 Professional 64 Bit and have an i7-4940-MX 3,1 GHz processor (4 cores). When I use in the example code below ...
0
votes
2answers
65 views

Color according to condition. [closed]

So, my problem is the following: I have the following table ...
3
votes
3answers
121 views

How to substitute Table environments by a more sophisticated code

I often use Tables inside of Tables to fill 2 dimensional arrays. Is it possible for the lower example code to substitute the Table environments by a more sophisticated and shorter code? ...
6
votes
4answers
478 views

A fast way to compute arrays avoiding If or Which

I found out that if I have to calculate huge arrays with most of the elements being zero( let's say each row has 10000 elements and only 8 are non zero) and the non zero elements' positions being ...
0
votes
1answer
55 views

Combining first 5 columns from CSV file into AbsoluteTime date

Thanks in advance for all your help. I need to import data from a CSV file that looks like : (easier to read in excel) I would like to convert the data into timestamps by creating a Table with 2 ...
1
vote
2answers
65 views

Export NDSolve data

I have calculated a solution of a system of differential equations using NDSolve and generated a plot. How could I extract the data of the solutions? The input is ...
1
vote
1answer
68 views

First come, first save in ParallelTable parallelization

Short version of the question: In C++'s OpenMP, I know how to get what I want, but I'm wondering whether Mathematica has the same option. It's called "dynamic scheduling" when parallelizing. Long ...
3
votes
1answer
69 views

Similar Table commands differ greatly in run time

With version 10.3.1 for Microsoft Windows (64-bit), the similar codes ...
1
vote
0answers
56 views
13
votes
6answers
914 views

Calling Table with custom iterator

I often find myself in situations where I, for example, need to build a table for some expression, but want to set the number of points rather then the step size, so the code ends up looking like this ...
0
votes
1answer
49 views

Grid with recurrence relation terms

I want to get the recurrence relation for several values of n in a grid form. At the moment I am using ...
1
vote
1answer
37 views

Access variable middle of the run [duplicate]

I execute a Table[] that need large time to be finished. If I abort it I loose what evaluated until now. Does it possible to stop running and save what evaluated ...
3
votes
2answers
81 views

Table of Buttons [duplicate]

What's the correct way to form a table of buttons in which each action depends on the index in the table? E.g., I want to get {Button[1,f[1]],Button[2,f[2]]} ...
2
votes
0answers
51 views

Transposing a table [closed]

I created this table so that it is a collection of 5 different functions that I need. It outputs the values that I want, however, I cannot figure out how to get the orientation right. I would like to ...
-1
votes
1answer
140 views

A pointer to the array in p1=Table in Table =p0 Eror [closed]

There is a circle of 10 points. How to draw another circle around this point from the first array? And so it drags along in the first circle. As in the program, drag the red. The coordinates of the ...
1
vote
1answer
410 views

Factor vector out of a matrix

I am wondering how to factor a[1],a[2],...,a[4] out of sim so that I can write sim as the ...
0
votes
1answer
57 views

Strange behavior of ParallelTable

I was trying to carry out the following calculations: ...
4
votes
2answers
95 views

Finding the smallest starting number producing a Collatz sequence of length 125 which ends with a value > 4

I'm supposed to do a Mathematica function that selects the smallest number not less or equal to 4 after 125 iterations. I am not good at coding, so some help/advice would be awesome. My code so far. ...
2
votes
2answers
77 views

Multiplying a table with constants

I have a table with coordinates {{x1,y1},{x2,y2}} that I want to multiply with a separate constant for x and one for y so: ...
2
votes
0answers
95 views

Fast construction and reshaping of large tensors

I'm trying to construct a large matrix which is derived from some higher rank tensor (the rank of interest to me changes case by case, so it needs to be a general method). Currently, the process of ...
2
votes
2answers
115 views

How can I increase the precision of my table?

I want to see first 15 digits for the values in the table computed below. ...
2
votes
3answers
54 views

Specify number of elements instead of step in Table [duplicate]

I think I have seen what I was looking for a ong time ago but I can't see nothing such in documentation. Quite often, I would like to create a Table with given ...
4
votes
1answer
137 views

How to increase the evaluation speed of this somewhat complicated table / matrix operation?

I'd like to calculate the following one-dimensional array: OneDimArray = Table[(Norm[Sum[ MatrixA[[i,j]]VectorB[[j]],{j,N}]])^2,{i,N}] However this takes a very ...
1
vote
1answer
191 views

Extracting data from NDSolve result

Normally I wouldn't ask such question before even read the material from the Wolfram Documentation about what I'm trying to do but this time I have a pretty tigh dead end. I apologize for that. So, ...
4
votes
1answer
89 views

How to combine two large tables and export them to .txt file?

I have two large tables. I shall post only 2 rows out of 100+. I shall name the first table blabla and the elements are: ...
1
vote
0answers
46 views

NIntegrate and Part issues [closed]

I'm trying to numerically evaluate an integral. To try and speed up the process, I decided to calculate some values that will be needed in advance using Parallel Tables. This is what I have: ...
3
votes
1answer
62 views

How to fill a tensor with matrices one by one?

I have this tensor: nn = 4; tableToFill = Table[x, {p, 1, nn}, {q, 1, nn}, {i, 1, nn}, {j, 1, nn}]; that I want to fill with a matrix one by one with a matrix ...
3
votes
3answers
177 views

Optimizing a series of basic matrix operations—scaling doesn't seem right with matrix size

I have a simple operation that I'd like to apply to an n×n matrix. My problem (well, one of them...) is that it runs in, say, 4 seconds for a 100×100 matrix, but it took five and a half minutes to run ...
-1
votes
1answer
79 views

Parallelize in Mathematica [duplicate]

Here is two test to understand the parallelize in Mathematica: ...
3
votes
1answer
113 views

Generate a 3D grid data table

I would like to generate a 3D Grid, not for displaying, but to do computations on it, so no draw functions I guess. I have a simple version of what I am thinking, however, it is terribly slow: ...
6
votes
2answers
2k views

How to export results of an analysis in table format into MS word file

I'm working on a simulation study using Mathematica 8. At the end of the analysis I'll have a matrix of data containing my results (assume for three variables like x,y & z). I used these codes for ...
2
votes
5answers
78 views

tabulating summation series with restrictions

Trying to solve this question for a good 5 hours but remained stuck. My intuition tells me I am missing something trivial that I've overlooked or forgotten. I am restricted only to the function 'table'...
0
votes
0answers
49 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 ...
1
vote
0answers
34 views

Defining an object which is function in some variables and tensor in some other indices

I am trying to define an object which function in some variable and tensor in other indices. My attempt at it was: ...
0
votes
0answers
57 views

FindRoot for vectors

My problem is the following: quad = 26; R is a quad x 3 matrix, lpand ...
1
vote
1answer
314 views

How to use Table to assign values to variables in a list?

I'm trying to do the following: R = {a, b, c, d, e, f, g, h, i}; Table[R[[n]] = RandomInteger[{0, 20}], {n, 1, Length[R]}] My intention is to assign a random ...
0
votes
2answers
105 views

How to evaluate function in the grid?

I have a function f[a_, b_]: = b^a + a b. a takes values {1,2,3,4}, and ...
1
vote
2answers
111 views

depicting specific element of a table (knowing its position) in different color

there is some 20 Time 20 tables, in each step we choose one element randomly. how can show this random selected element with different color?
2
votes
1answer
49 views

Add text label in the top-left of a TableForm

I have a function that should give a multiplication table for an integer input: TableForm[Outer[Times, Range[#], Range[#]], TableHeadings -> Automatic]& ...
1
vote
1answer
55 views

Problem averaging multiple series of data [duplicate]

Recently I'm having trouble figuring out a certain problem in Mathematica. I have a table of data in the following arrangement: {series no., x, y} Now, each series of data has exactly the same x ...
2
votes
1answer
123 views

order items of a table

I am trying to change order of a table. ...
2
votes
1answer
270 views

Appending elements to a list in parallel table

Is there any way to store values in a list that is being computed in parallel? For example, if ParallelTable is computing some ...
0
votes
1answer
131 views

Follow up: how to evaluate this double sum quickly

This question is a follow-up to my previous question. The code I use at the moment is the following: ...
6
votes
2answers
163 views

Grouping the list of numbers that have common.

I am working on some simple problem. It is like puzzle.. Let's say I have some list input={{1,1},{1,2},{1,3},{2,3},{3,3},{4,4}} Which means 1 can go and back to ...
2
votes
1answer
98 views

How to download tables from a url?

I'm trying to import all the tables on a website, this one in particular: https://aws.amazon.com/ec2/pricing/ For local files that are already tabular, ...
2
votes
3answers
66 views

Having a function check a column and perform a task every time an entry satisfies a condition

So I have a matrix (technically a table) points = Table[{x, f[x]}, {x, Range[0, 2, .1]}]; Which gives something like this in matrixform \begin{array}{cc} ...
0
votes
1answer
58 views

Indexing a value within a table function

Is what I'm looking to do possible? I know that I can get it to work with a for loop, but a table would make things much neater. What I need to do while calculation the table below is to reset the ...
1
vote
1answer
81 views

Defining function from table [closed]

I have a table of values of the form Table[{i1,j1}, {i2,j2}...] and I want to define a function like f[i] to take the values ...