# 10.1.7. Polar plots and aspect ratioΒΆ

File 07-polar-aspect.py in folder demo/plotting/

```import pyopus.plotter as pyopl
from numpy import arange, sin, cos, exp, pi, e

if __name__ == '__main__':
# Initialize gui thread, clean up.
pyopl.init()
pyopl.close()

# Plot data - sin(x), cos(x), exp(x/pi) .. for x in [0, 2pi] with 0.2 step.
t = arange(0.0, 10*pi, 0.2)
r = 100/(10+t)
y = sin(t)*r
x = cos(t)*r

# Plot window
f1=pyopl.figure(windowTitle="xy and polar plot", figpx=(800,400), dpi=100)

# Lock GUI
pyopl.lock(True)

# Check if figure is alive
if pyopl.alive(f1):
# Create 2 subplots, horizontal stack of 2
ax1=f1.add_subplot(1,2,1, aspect='equal')	# Equal aspect ratio
ax2=f1.add_subplot(1,2,2, aspect='equal', projection='polar')	# Equal aspect ratio, polar plot

# First axes
ax1.plot(x, y, '-', label='sin(x)', color=(1,0,0))
ax1.grid(True)
ax1.set_xlabel('x')
ax1.set_ylabel('y')
ax1.set_title('Equal aspect ratio, x-y plot')

# Second axes
ax2.plot(t, r, '-', label='r=r(t)', color=(1,0,0))
ax2.grid(True)

# Get r limits
r1=ax2.get_rmin()
r2=ax2.get_rmax()
print("R limits: %f..%f" % (r1, r2))
# Reduce rmax by 20%, set rmin to 5.0. The latter means that only
# points with r>=5 are plotted. Points with r=5 are at the origin.
ax2.set_rmin(5.0)
ax2.set_rmax(r2*0.8)
ax2.set_title('Equal aspect ratio, polar plot r=r(t)')

# Draw figure on screen
pyopl.draw(f1)

# Unlock GUI
pyopl.lock(False)

# Handle keyboard interrupts properly.
pyopl.join()
```