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.

learn more… | top users | synonyms

4
votes
1answer
115 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 ...
4
votes
2answers
2k views

How to create a Table of Tables with indexed variables

I want to use concise code to generate a table of values that list the addition of a set of vectors. What I am looking for is essentially a Table of Tables. I will show here the kind of lists I want, ...
4
votes
1answer
75 views

Joining table of tuples with table of scalar values [closed]

I have a table of dimension $M \times N \times Q$ of 3-tuples {x,y,z} that represent points, and another table of dimension $M \times N \times Q$ of scalar values. ...
4
votes
2answers
302 views

Selecting y-values from xy coordinate grid

Suppose I have a table, u, which is created as follows: ...
4
votes
2answers
89 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. ...
4
votes
2answers
218 views

Mysterious behaviour of ParallelTable

This question is related to Export bug in combination with ParallelTable?. The following code shows an even stranger bug than in the upper question. The y-axis should always be logarithmic, but in ...
4
votes
2answers
229 views

How to make sure Table or Do only runs through specific values?

I often need to generate or run through very large numbers of integers (we're talking {i, 1, 10^9} and higher) and want to add certain integers to a list, say ...
4
votes
2answers
976 views

What is the Mathematica way of joining two tables?

Is there a special Mathematica way of joining tables of data together, so that I would get similar functionality as if I was running a database with sql? For example, I have one particular table ...
4
votes
1answer
88 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: ...
4
votes
1answer
640 views

Create a table with inline conditions

I am trying to create a table with conditionals inline. For example, I'd like to create a 2 dimensional table like this: ...
3
votes
3answers
4k views

Importing multiple files using a for-loop

once again I am stuck solving a seemingly easy problem :( I would like to make a List of tables by importing data from several txt-Files. Importing the data into a table works so far and I am able to ...
3
votes
3answers
177 views

Drop in nested tables?

I want to drop a specified number of elements from a 'table ...
3
votes
3answers
175 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 ...
3
votes
5answers
423 views

Creating a conditional table

I'm trying to create a conditional table. Let's say I want to have such result: {1,2,3,4,5,0,0,0,0,0}. The idea is to create a table of n elements (10 in a given example), but when one element takes ...
3
votes
2answers
453 views

How do I display the plane of best fit in 3D?

I'm trying to display the plane of best fit in the same 3D-box. Currently, I have the following code which spits out a plot of the points in 3D. I want to have a plane of best fit, can Mathematica do ...
3
votes
3answers
118 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? ...
3
votes
4answers
265 views

AccountingForm w/o significant figures

Basically I want to build a chart like something I would do in Excel. It should look like this: Here is the formula I'm using and what I've done so far ...
3
votes
4answers
356 views

Are table headings functional?

Are table headings for aesthetics only? For example, if I have: ...
3
votes
1answer
320 views

How can I create a colour image using raw black and white data? (FITS data cube)

I have a data cube containing pictures of a galaxy across a thousand wavelengths. I want to take the data for the image slides in the red and blue parts of the spectrum, and have them represented in ...
3
votes
1answer
660 views

Suppress warnings in ParallelTable

I'm using ParallelTable to evaluate a function that involves NIntegrate. There are a lot of ...
3
votes
3answers
211 views

How to make a defined symbol stay in symbol form?

How to make a defined symbol stay in symbol form? w = 3; g = 4; {w, g}[[2]] 3 I want the output to be ...
3
votes
1answer
767 views

How to convert an output to a graphic that can be selected like a plot?

EDIT: István Zachar informed me of the Rasterize[] command, which does exactly what I need. Danke! I have a self-built function that uses Grid[] to create a table that is more presentation-friendly ...
3
votes
1answer
73 views

Table with programmatically specified number of iterators in Compile

Compare two ways of computing a table of values of a multivariable Gaussian: ...
3
votes
2answers
79 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]]} ...
3
votes
1answer
86 views

How to make a table with from two lists?

I have two lists. ...
3
votes
2answers
426 views

How to create a 'shortest-path link matrix'?

I am currently struggling with a problem in Mathematica. I have a randomly generated weighted Barabasi-Albert graph and a corresponding demand matrix of the same size. I'm generating the graph with ...
3
votes
1answer
638 views

Why am I getting so many error messages from my pendulum simulation?

I'm doing my end of semester project for a physics class. We were supposed to graphically model a physical occurrence; I chose doing a Pendulum Wave. I have my code written, however Mathematica keeps ...
3
votes
1answer
405 views

Why can't Mathematica parallelize this?

The following code makes mathematica print "ParallelTable::nopar1: [...] cannot be parallelized; proceeding with sequential evaluation." ...
3
votes
1answer
110 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: ...
3
votes
1answer
159 views

Table with some editable cells

I have a table: I want it to be editable only where the zeros appear. I read this post Generating an editable table that can be used as input because it's almost exactly what I want, but I couln't ...
3
votes
1answer
710 views

Cartesian product of sets

I have two types of sets, one of them is a list of points of the form $\{t_{k}\}$ and the other one is an interval of the form $[a,b]$. And my custom set consists of these type of sets and I need to ...
3
votes
2answers
673 views

How to export a table of complex numbers?

I'm having problems exporting a table of complex numbers. I have: ...
3
votes
1answer
119 views

Plotting a table with many y values

I'm trying to plot a bifurcation map for a Lorenz System. I have a function (called estables in the code that follows) which, for a certain value r, returns the ...
3
votes
4answers
135 views

Find the length of the intersection of two lists including duplicates

I have 2 Lists. The first one includes all the numbers from 1 to 10. listA={1,2,3,4,5,6,7,8,9,10} The second includes ...
3
votes
1answer
60 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
1answer
186 views

Print array with indices

Is there a single function that prints an array together with the indices? I know how to achieve this with Grid[{Range[n],array},Frame->All], but I vaguely ...
3
votes
3answers
125 views

Combination of interpolations doesn't work?

I have tables of function values f[i_] and g[i_] and I need to plot various combinations of the function and its derivatives ...
3
votes
2answers
238 views

Problem with exporting lists to Excel

When I use the form Export["file", list, "Table"] to export a list to Excel, I get columns of lists. I want my Excel sheet to have each list element in a separate ...
3
votes
2answers
457 views

Converting from TableForm to Grid

I wonder if there is an easy way to convert from TableForm to Grid. I have an existing data format that uses the Table function that I’d like to prettify…. Let’s setup a nested table as follows: ...
3
votes
2answers
84 views

Faster use of Condition for a large array (see the example)

Here is the example/problem. I have a array of $n$ random number. n = 2000; p = RandomReal[{0, 9}, n]; I have to create a $n\times n$ sparse matrix with ...
3
votes
1answer
335 views

Table with dynamic iterator

I would like to make a Table whose iterator has a dynamically updated endpoint, i.e. Table[i,{i,1,Dynamic[n]}] Is this possible? Here is the context: ...
3
votes
1answer
41 views

Table headings for a single column of data?

Is there a way to get this to work? data = {2, 1, 4, 3}; TableForm[ data, TableHeadings -> { {"L1", "L2", "L3", "L4"}, {"data"} } ]
3
votes
1answer
66 views

Similar Table commands differ greatly in run time

With version 10.3.1 for Microsoft Windows (64-bit), the similar codes ...
3
votes
1answer
682 views

Exporting/Importing a Table of complex numbers

I'm generating a long table of list of the form: PN={{1,2,1+i},{3.5,2.6,2}...},{...},... Using: Export["PN.dat", PN, "Table"] ...
3
votes
1answer
122 views

Table doesn't replace inside conditionals (If, Which) [duplicate]

This: Table[If[cond, y], {y, 1, 3}] outputs this: {If[cond, y], If[cond, y], If[cond, y]} The ...
2
votes
4answers
424 views

How do I find the position of the maximum value in each column of a table?

Given a table of values, I know how to find find maximum values, but how do I find the position of the maximum value in each column. For example, given ...
2
votes
3answers
239 views

how can I generate a sequence of assignments?

I want to make a sequence like follows r[1]= r[2]= r[3]= r[4]= .... r[n]= The above r[i] represents coordinates which I have ...
2
votes
4answers
130 views

Table and IF statement

I want to make a table to get a nbyn matrix. However, the diagonal are divided by zero. For example: n = 5; Table[1/(Sin[i] - Sin[j]), {i, 1., n}, {j, 1, n}] I ...
2
votes
2answers
155 views

How do you program a large table and search the minimum in each column? [closed]

How does one program a table (2d list) with a huge amount of data which can be done manually. For example: the rows go from -1 to 1 by step 0.0005 and the columns go from -3 to 3 by step 1. ...
2
votes
3answers
179 views

Extracing information from a table

I am new to Mathematica. I have created a table of real numbers. I want to create a new table that contains the set of values of $i$ such that, in my original table, the $i$th entry is greater than ...