Mathematica plot vector field from data file

Question

I am trying to plot a vector field from data file. I can put the data into file in any way, but for now data file contains information in this form:

x y Fx Fy

where Fx and Fy are x and y components of a vector.

Any ideas how to plot it?

Answer 1

Given a a file vector.txt in an appropriate location containing exactly eight lines

1 1 2 3
1 2 5 3
1 3 4 5
1 4 2 2
2 1 3 3
2 2 5 6
2 3 4 1
2 4 1 4

(without any additional white space anywhere)

and a fresh Mathematica notebook containing

datain = Partition[ToExpression[ "{" <>
 StringReplace[Import["vector.txt"], 
  RegularExpression["\\s"] -> ","] <> "}"], 4];
arrow = Map[Arrow[{Take[#, 2], Take[#, 2] + Drop[#, 2]}] &, datain];
Graphics[arrow]

Evaluate that and a small collection of arrows appears in the notebook.