Question

I need to plot a function on a coordinate system that has its origin at the center of the screen (or somewhere near the center, but not necessarily in the center) and I need to draw axes so that they cross at the origin. Axes should have labels and tics as well, and arrows.

I have no idea how to do this efficiently, so far in my code I manually set offsets for my tics, and draw arrows manually using offsets as well. I also set offsets on the axes labels. All this is very fragile, and offsets change depending on the terminal settings.

Would someone please help me with a sample code or an explanation how to do this the right way?

Answer 1

Well, using _zeroaxis is the “right” way to go to get the tics and labels in: setting the _range gives you the symmetry to make 0,0 centre … and once you know the _range, you can draw arrows on manually.

set xzeroaxis
set xtics axis
set xrange [-10:10]
set arrow 1 from -9,0 to -10,0
set arrow 2 from  9,0 to  10,0

set yzeroaxis
set ytics axis
set yrange [-1:1]
set arrow 3 from 0,-.9 to 0,-1
set arrow 4 from 0,.9  to 0,1

set border 0

plot sin(x)