I've got a list of two-dimensional points represented in a numpy style array:
lines = np.array([
[[1,1], [2,3]], # line 1 (x,y) -> (x,y)
[[-1,1], [-2,2]], # line 2 (x,y) -> (x,y)
[[1,-1], [2,-7]] # line 3 (x,y) -> (x,y)
])
I'd like to plot these lines with matplotlib in the simplest form possible.
However, most of matplotlib's methods expect points to be represented component wise like ([x1, x2, x3, ...], [y1, y2, y3, ...]) instead of point wise.
I managed to get the slices right for a quiver type plot with vectors:
x = lines[:,0,0]
y = lines[:,0,1]
u = lines[:,1,0]
v = lines[:,1,1]
# quiver([X, Y], U, V, [C], **kwargs)
plt.quiver(x, y, u, v, color=['r','b','g'], scale=1, scale_units='xy', angles='xy')
plt.xticks(np.arange(-10, 10, 1))
plt.yticks(np.arange(-10, 10, 1))
plt.grid()
plt.show()
But it's my impression that quiver isn't really the right type of plot for my use case. Especially the scale, scale_units and angles arguments took me quite a while to figure out. Without them, vectors were displayed "wrong".
I'd rather use the simpler plot, in this signature
plot([x], y, [fmt], [x2], y2, [fmt2], ..., **kwargs)
which for each line to plot expects the two x coordinates followed by the y coordinates.
So for the lines above, we need
rearranged = [ [1,2],[1,3], [-1,-2],[1,2], [1,2],[-1,-7] ]
# ^line1 ^line2 ^line3
If I add these to a call of plot statically, it's exactly what I need.
Question is, how can I slice or rearrange my initial lines array?
All I've got so far is
lines[:,[0,0],[0,1]]
but that only gives me the x coordinates of each line:
[[ 1 1]
[-1 1]
[ 1 -1]]
