Note
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Integral as the area under a curve#
Although this is a simple example, it demonstrates some important tweaks:
A simple line plot with custom color and line width.
A shaded region created using a Polygon patch.
A text label with mathtext rendering.
figtext calls to label the x- and y-axes.
Use of axis spines to hide the top and right spines.
Custom tick placement and labels.
importmatplotlib.pyplotaspltimportnumpyasnpfrommatplotlib.patchesimportPolygondeffunc(x):return(x-3)*(x-5)*(x-7)+85a,b=2,9# integral limitsx=np.linspace(0,10)y=func(x)fig,ax=plt.subplots()ax.plot(x,y,'r',linewidth=2)ax.set_ylim(bottom=0)# Make the shaded regionix=np.linspace(a,b)iy=func(ix)verts=[(a,0),*zip(ix,iy),(b,0)]poly=Polygon(verts,facecolor='0.9',edgecolor='0.5')ax.add_patch(poly)ax.text(0.5*(a+b),30,r"$\int_a^b f(x)\mathrm{d}x$",horizontalalignment='center',fontsize=20)fig.text(0.9,0.05,'$x$')fig.text(0.1,0.9,'$y$')ax.spines[['top','right']].set_visible(False)ax.set_xticks([a,b],labels=['$a$','$b$'])ax.set_yticks([])plt.show()