This is a package for introductory microeconomics topics. Find additional code, albeit unpackaged, in the loose-code branch. This new refactor does not yet have all of the same capabilities as in the old unpackaged code.
Demand and Supply objects can be created in several ways, but most naturally with the from_formula class method. The method requires an explicit slope, so "P=12-1*Q" or "P=12-1Q" must be used instead of "P=12-Q".
from microecon.curves import Demand, Supply
d1 = Demand.from_formula("Q = 10 - 1*P")
d2 = Demand.from_formula("P = 15 - 2*Q")
s1 = Supply.from_formula('Q = 2*P')
s2 = Supply.from_formula('Q = 2*P - 1')
The addition operator performs horizontal summation, allowing aggregation.
d = d1 + d2
s = s1 + s2
Then you can solve for and plot an equilibrium.
from microecon.equilibrium import Equilibrium
e = Equilibrium(d, s)
print(e.p, e.q)
e.plot()
Use matplotlib to customize plots further.
import matplotlib.pyplot as plt
fig, ax = plt.subplots()
e.plot(ax=ax)
ax.set_ylim(0, 16)
ax.set_xlabel("Quantity")
ax.set_ylabel("Price")
# Label curves
ax.text(2, d(2) + 0.05,
s='D',
fontsize=16,
horizontalalignment='left',
verticalalignment='bottom')
ax.text(16, s(16) + 0.05,
s='S',
fontsize=16,
horizontalalignment='right',
verticalalignment='bottom')
# Label equilibrium
ax.plot([e.q], [e.p], marker='o', markersize=10)
ax.text(e.q, e.p + 2,
s=f'Q={e.q:.2f}, P={e.p:.2f}',
horizontalalignment='center',
verticalalignment='bottom')
plt.savefig("equilibrium.svg", transparent=True)
plt.show()
