Copy/Pasting a Grid of Numbers from Project Euler

Question

On Project Euler Problem 11 (link: https://projecteuler.net/problem=11), there is a 20x20 grid of numbers. However, when I pasted it into Mathematica, I got this strange result where the times symbol 'x' is interlaced between the numbers.

Here is an image that shows this (again, this grid is directly copy/pasted from the website): http://i.gyazo.com/6336b0c44a1cb6afef7ee3f962c06522.png

Are there any in-line commands/functions you can use on that mass of numbers so that you can enter everything once and it will return a nicely formatted list/matrix? The only way I could think of, which did not make use of in-line commands, was very tedious: Ctrl+F --> Replace all "x" with "," and then manually entering curly brackets to turn the grid into a list/matrix.

Ideally, I want to turn it into something like {{1,2,3},{4,5,6},{7,8,9}}, but of course with the appropriate elements.

Edit: From this StackExchange post (Cut and paste data from a spreadsheet), I found that

data = ImportString["(copy/paste grid here)", "TSV"]

works exactly as desired :)

Edit 2: Just kidding, the above doesn't work. It doesn't add commas.

Karsten7 · Accepted Answer · 2015-06-29T03:49:58.767

9

Here is one way to import the grid into Mathematica

Partition[
 StringCases[
  Import["http://projecteuler.net/problem=11", "Plaintext"], 
  DigitCharacter ..][[10 ;; -8]], 
 20] // ToExpression

edited Jun 29 '15 at 03:49

answered Jun 29 '15 at 03:23

Karsten7

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Thank you for this :) Can you explain what the ". . " are for? I looked in the documentation for DigitCharacter, and that seems to be paired with the function, kind of like how pure functions involve the pairing of # and &. – user155812 Jun 29 '15 at 03:35
1

@AisforAmbition It is a String Pattern. DigitCharacter .. means one or more digits. – Karsten7 Jun 29 '15 at 03:39
A problem I ran into was that since this treats every digit as a string and not a standard number, the inside elements cannot be operated upon by the Times function. What can I do if I want to multiply the matrix's first diagonal, for example? – user155812 Jun 29 '15 at 03:46
Ah, thank you very much :) – user155812 Jun 29 '15 at 03:50
1

@Karsten7., output is the same w/o "Plaintext". – alancalvitti Jun 29 '15 at 17:38
@alancalvitti Yes, "Plaintext" is the default element used by Import. – Karsten7 Jun 29 '15 at 19:08

score 5 · Answer 2 · edited Apr 13 '17 at 12:55

5

Szabolcs's Past Tabular Data palette still works just like it should. This palette is so useful it is one of only two I always open on start-up.

If for some reason you are looking for a one-off solution here is mine:

Block[{Times = List}, (*paste here*) ] ~Partition~ 20

Reference: Convert head Times to List

edited Apr 13 '17 at 12:55

Community

1

answered Jun 29 '15 at 08:44

Mr.Wizard

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Very elegant method, Mr. Wizard. Once again, you've been a tremendous help :) Thank you! – user155812 Jun 29 '15 at 09:05
Nice. With and Module also work. – alancalvitti Jun 29 '15 at 17:43

score 1 · Answer 3 · answered Jun 29 '15 at 15:49

1

Highlight the list and paste into a text file and then

t=Import["put path of text file in here","Table"]
t//MatrixForm

works for me. Does it work for anyone else?

answered Jun 29 '15 at 15:49

bobbym

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No, I get HTML, eventually containing ... {32, 98, 81, 28, 64, 23, 67, 10, "<span", \ "style=\"color:#ff0000;\"><b>26</b></span>", 38, 40, ... – alancalvitti Jun 29 '15 at 17:50
It certainly ought to. This is the basic method without direct copy-and-paste, but it's the one I used for years before the introduction of ImportString. – Mr.Wizard Jun 29 '15 at 17:51
@alancalvitti Is your browser really copying HTML code? Which do you use? – Mr.Wizard Jun 29 '15 at 17:51
@Mr.Wizard Possible confusion: bobbym wrote "put path..." so I used Import["http://projecteuler.net/problem=11","Table"] – alancalvitti Jun 29 '15 at 17:52
@alancalvitti but first Highlight the list and paste into a text file and then – Mr.Wizard Jun 29 '15 at 17:58
@alancalvitti the text file is on your machine, so put the path of it in between the quotes. – bobbym Jun 29 '15 at 23:34
@Mr.Wizard & bobbym, too many steps: http://www.amazon.com/Smaller-Faster-Lighter-Denser-Cheaper/dp/1610392051 – alancalvitti Jun 30 '15 at 17:07
Hi alancalvitti, hard to argue with that. – bobbym Jun 30 '15 at 23:33

Copy/Pasting a Grid of Numbers from Project Euler

3 Answers3