1 from math
import pi
, atan2
7 # we abuse a parametric function below, so we express everything in terms of a parameter k
8 x
= lambda k
: int(k
)/11
9 y
= lambda k
: int(k
)%11
10 z
= lambda k
: x(k
) + y(k
) * 1j
11 f
= lambda k
: 1/(z(k
)-z1
)/(z(k
)-z2
) # function to be plotted
12 s
= lambda k
: 5*abs(f(k
)) # magnitude of function value
13 a
= lambda k
: 180/pi
*atan2(f(k
).imag
, f(k
).real
) # direction of function value
15 g
= graph
.graphxy(width
=8,
16 x
=graph
.axis
.linear(min=0, max=10),
17 y
=graph
.axis
.linear(min=0, max=10))
18 g
.plot(graph
.data
.paramfunction("k", 0, 120,
19 "x, y, size, angle = x(k), y(k), s(k), a(k)",
20 points
=121, context
=locals()),# access extern
21 [graph
.style
.arrow()]) # variables&functions
22 g
.writeEPSfile("arrows") # by passing a context
23 g
.writePDFfile("arrows") # by passing a context
