# Importing a Matrix whit different column numbers depending on the row

I have a bunch of coordinates given in a file. The file contains Startpoints and Endpoints of arrows in columns(Example):

t    start1    end1    start1   end2
1    1  2     2  2    0  0     1  1
2    0  0     1  4


Where the number of arrows is not constant over time. I tried to read the file like this and it did not work (especially the No_of_columns which gives the number of columns for a given row should depend on the row number as each row does not contain the same number of coordinates):

{{#1, #2}, {#3, #4}} & @@@ #[[All, 1 ;; No_of_columns(row) ;; 4]] &/Arrows;


I could also output another file stating the number of coordinate pairs in each row:

t   No_of_arrows


So basically I need a matrix whose column number is not the same for all rows. Is that even possible?

EDIT:

https://www.dropbox.com/s/xuuc6v0az73k49e/arrows.txt

EDIT2:

I will try to be more specific. I created (with a lot of help) a code animating rectangles movement in 2D. In the next step I want to connect those rectangles by arrows. Importantly those arrows come and go so that I would have to give another file stating the number of arrows at each time point (maybe?).

So for now I need data looking like this (?)

Arrow_coordinates={{{{1,2},{2,2}},{{0,0},{1,1}}},{{{0,0},{1,4}}}}


In this case I could run an animation with 2 arrows in the first step and 1 in the second step.

Animation of moving rectangles in 2D from data file

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Can you please provide the actually file that you are importing? –  Öskå Jun 2 at 12:01
Its just a huge file with several thousand lines which I need another computer to produce. For now I am experimenting with the 2 lines above, where the first one contains 2 arrows and the 2nd one only one. –  user3683367 Jun 2 at 12:46
Then provide a text file with a few lines formatted in the same way as your huge file.. :) Because here you have spaces, you may have tabulations in your text file. –  Öskå Jun 2 at 12:48
OK I added the file –  user3683367 Jun 2 at 12:53
Does it work if you use {{#1, #2}, {#3, #4}} & @@@ #[[All, 1 ;; -1 ;; 4]] &/@Arrows? –  kguler Jun 2 at 13:21

data = Import["http://pastebin.com/raw.php?i=1Wmx3GKH", "Data"];