I have the data stored in the textfile like this:
0.5 0.5 -0.7 -0.8
0.51 0.51 -0.75 -0.85
0.6 0.1 0.1 1.00
and so on
4 numbers in each row. Two first numbers means coordinates (x0,y0), two last - (x1,y1). This determines the coordinates of a line. So, the first row tells, that I have a line starting from (0.5, 0.5) and finishing in (-0.7, -0.8). The aim is to plot all of these lines. How can I do this? Explain it for beginner, please.