It is a function that was created for this assignment, The code of it is
def plt_roast(X,Y):
Y = Y.reshape(-1,)
colormap = np.array(['r', 'b'])
fig, ax = plt.subplots(1,1,)
ax.scatter(X[Y==1,0],X[Y==1,1], s=70, marker='x', c='red', label="Good Roast" )
ax.scatter(X[Y==0,0],X[Y==0,1], s=100, marker='o', facecolors='none',
edgecolors=dlc["dldarkblue"],linewidth=1, label="Bad Roast")
tr = np.linspace(175,260,50)
ax.plot(tr, (-3/85) * tr + 21, color=dlc["dlpurple"],linewidth=1)
ax.axhline(y=12,color=dlc["dlpurple"],linewidth=1)
ax.axvline(x=175,color=dlc["dlpurple"],linewidth=1)
ax.set_title(f"Coffee Roasting", size=16)
ax.set_xlabel("Temperature \n(Celsius)",size=12)
ax.set_ylabel("Duration \n(minutes)",size=12)
ax.legend(loc='upper right')
plt.show()
The implementation of it is in the lab_coffee_utils.py, You can download it and get all the functions in this file, This thread is about how to download files in your PC
Cheers,
Abdelrahman