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17
votes
5answers
656 views

Instruct a Table to only evaluate until a condition is fulfilled

I am looking for the way of building a Table of pairs of numbers in a fast way. My true table evaluates huge functions, and I see no way and reason to show those cumbersome expressions here. Let us ...
10
votes
6answers
661 views

Multiplying two dimensional data by a constant

I have a list of lists of the form: {{1, 2}, {2, 4}, {2, 8}} But I want to multiply only the second dimension of that data by a constant. I know I could do this ...
10
votes
2answers
2k views

Is there a Mathematica equivalent to MATLAB's logspace? [duplicate]

Possible Duplicate: How can I get exactly 5 logarithmic divisions of an interval? I want to use Table to generate a list of items, but want the indices ...
10
votes
5answers
378 views

Relational joining of tables

A common thing to want to do with data is to combine it (at least I thought this was a common thing). In SQL there is the idea of table joins "select id,v1,v2 from A,B where A.id=B.id" kind of thing. ...
8
votes
5answers
330 views

TableAlignments -> Left not working

For a very simple dataset TableAlignments->Left does not work: ...
8
votes
1answer
161 views

Why is building a table of function values so much slower than just plotting the function?

Here is a function that take some time to evaluate: n = 1000; coeffs = RandomVariate[NormalDistribution[], n]; f[x_] := Sum[coeffs[[k]] Sin[k x]/k, {k, 1, n}]; ...
8
votes
2answers
249 views

Correct way to generate large data sets (i.e.forward yield curve )

I would like to generate a set of forward yield curve matrix of size 1000 x 100. First I defined my SparseArray of 1000 x100: ...
7
votes
3answers
238 views

How do I avoid scoping collisions of iterator variables?

Yesterday I had an issue that kept for quite a while. My code wasn't producing the right results. Now I know why and I am wondering how to avoid the issue in future. Consider the following code. ...
6
votes
2answers
374 views

Merging two Lists

I have two tables. One is given by T1 = Table[{x, y, 0.}, {x, 0, V},{y, 0, V}] and from a calculation I have the second, a list of points {x, y, z} ...
6
votes
7answers
296 views

A problem involving classification of data

Toady, I encountered a problem while trying to classify certain data. I have the coordinates of six points. ...
5
votes
4answers
417 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 ...
5
votes
4answers
174 views

Creating simple table

How do I create a table like this? I find it very hard to create the zero-row and zero-column. Edit: I am looking for a solution where a formula eg. Table or something else is being used. I can ...
5
votes
2answers
933 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 ...
5
votes
2answers
268 views

Is there a Break[] equivalent for short-circuiting in Table?

I am running Mathematica 7. The following is admittedly a silly example, but suppose that I have a list list whose entries are either ...
5
votes
2answers
292 views

How to create this list more elegantly

There is list containing some $(i,j)$ values of indices. Now i want to create a matrix of dimension n $\times$ m whose entries are 1 for the indices corresponding to the given list otherwise its ...
5
votes
2answers
175 views

Interactive grid

I would like to create an interactive grid, whereby one number from a grid is selected by the cursor ("3" in the example below), and all other numbers in the grid are highlighted that are related to ...
5
votes
1answer
232 views

Making the TableForm output into two columns

I have a program that calculates Christoffel symbols for a given metric, and the output I'm getting now is such that I have every calculated symbol in one column like this: I'd like that I could ...
5
votes
1answer
97 views

Finding minimum fly-by radius between Mars and spacecraft from interpolating function

I've written an interplanetary trajectory solver/plotter that plots the path taken by a spacecraft on an Earth-Mars mission, but have run into a little trouble when the spacecraft actually reaches ...
4
votes
5answers
197 views

How to make a table of $\sum_{i=1}^n$?

I want to create a table of $\displaystyle \sum_{i=1}^n i^k$ for $1\le k\le 5$. The output I want to obtain is a TeXForm output as follows. \begin{align} ...
4
votes
2answers
197 views

Extracting data from a table under conditions

I have a very large table with two columns. Let's say the name of first column is E and the name of the second is P. How can I get the E values when P = 0.
4
votes
2answers
201 views

Labeling a grid

I have m = {{0, -1, -2, -3, -4}, {1, 0, -1, -2, -3}, {2, 1, 0, -1, -2}, {3, 2, 1, 0, -1}, {4, 3, 2, 1, 0}}; And a grid ...
4
votes
3answers
143 views

Using If statements internal to Table [duplicate]

Is there a way to use If statements with Table? To give a kind of ridiculous example that captures to spirit of what I'm trying ...
4
votes
2answers
828 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
2answers
248 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 ...
3
votes
8answers
337 views

How to add a column to a table that counts the number of times the lines appear?

I am at a complete loss at this. I have a table with 2 columns and n lines. Some of the lines are repeated. What I want to do is add a new column that counts the number of repetitions of each line. ...
3
votes
4answers
684 views

How can I format a table to look nice?

I have this code, but i would like to see the results well formated, How can I obtain a well formatted data with aligment?, similar to this one insted what i obatin, you can see here Here is ...
3
votes
4answers
138 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
2answers
96 views

TableForm with a title

My question is rather simple. I want to put a title into a table. For example, consider a list with depth two and a title ...
3
votes
1answer
326 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
249 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
213 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
156 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 ...
3
votes
1answer
223 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
1answer
349 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"] ...
2
votes
3answers
198 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
3answers
165 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 ...
2
votes
2answers
254 views

Get positions of all non zero matrix elements

I want to find all non zero elements of a table and I want to create a list that contains the name of the table the element was removed from, the position of the element, and the value of the element. ...
2
votes
2answers
268 views

How to populate a table using a rule replacement

I am trying to populate the rows and columns of a table by using a rule replacment. To generate a table that looks like this For example Sc would be row 1, column 1. An example of a record looks ...
2
votes
2answers
94 views

Create a matrix of matrices using Band and ArrayFlatten [duplicate]

I can easily write a simple Band matrix using: SparseArray[{Band[{2, 1}] -> a}, {Dim, Dim}] where a is a number. Now, I ...
2
votes
2answers
426 views

Fast way to extract data from a list

I used data=Table[{i,f[i]},{i,1,n}] to produce a list, here n is greater than 2^20 = 1048576. The function f(N) runs in time ...
2
votes
2answers
180 views

Table of Variables

I use a list of variables {x1, x2, x3} to Solve a particular set of equations. I am now trying to generalise this depending on ...
2
votes
2answers
203 views

Deleting parts of groups that do not have equal dates

Find the intersection of dates within the pair and remove the other dates & corresponding prices. Also keep the list in same format as it currently is in. Let me explain: Each stock has closing ...
2
votes
1answer
149 views

Errors when using ParallelTable inside a package

I'm developing a package that contains a function that requires evaluation of an expensive Table, so I use ParallelTable ...
2
votes
2answers
156 views

Replacing all values in a table > $T$ [duplicate]

I want to generate a table of Euclidean distances from the points in a list to a given point, e.g.: ...
2
votes
1answer
177 views

Find points on the surface of a Graphics3D object

If I have a Graphics3D object that was generated from manipulations to PolyhedronData rather than via an explicit equation, for example the Spikey (for which the entire code can be found here The ...
2
votes
2answers
146 views

How can I create a table of sliders?

I'm trying to do the following: I have a table: w = Table[ToExpression[ToString[h] <> ToString[i]], {i, 1, Length[c]}] This table is suposed to generate ...
2
votes
3answers
89 views

One-column table not properly displayed by TableForm

I want a table with a single column of data, and with headings along both the rows and the column. One might expect it to work like this: ...
2
votes
1answer
154 views
2
votes
2answers
243 views

Parametric plot of multiple graphs on the same axes

I'm trying to plot on a single axes system multiple graphs but ran into a problem when tryinf to label my graphs. Here's what I've used so far Mathematica code: ...
2
votes
1answer
174 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 ...