def plot_field(function):
'''Return a Gnuplot command to plot a field.'''
s = "plot '-' with vectors head\n"
separation = WORLDSIZE / SAMPLES
end = WORLDSIZE / 2 - separation / 2
start = -end
points = ((x, y) for x in linspace(start, end, SAMPLES)
for y in linspace(start, end, SAMPLES))
for x, y in points:
tank = Answer()
tank.index = 0
tank.x = x
tank.y = y
tank.angle = 0
tank.flag = '-'
vec = function(tank)
plotvalues = gpi_point(x, y, vec[0], vec[1])
if plotvalues is not None:
x1, y1, x2, y2 = plotvalues
s += '%s %s %s %s\n' % (x1, y1, x2, y2)
s += 'e\n'
return s
def show_arrows(plot, potential_func, obstacles, xlim=(-400, 400), ylim=(-400, 400), res=20):
"""
Arguments:
fns: a list of potential field functions
xlim, ylim: the limits of the plot
res: resolution for (spacing between) arrows
"""
plot.set_xlim(xlim)
plot.set_ylim(ylim)
for x in range(xlim[0], xlim[1] + res, res):
for y in range(ylim[0], ylim[1] + res, res):
tank = Answer()
tank.x = x
tank.y = y
tank.index = 1
tank.goal = "-"
dx, dy = potential_func(tank, obstacles)
if dx + dy == 0: continue
plot.arrow(x, y, dx, dy, head_width=res/7.0, color='red', linewidth=.3)
