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Anchored Artists#
This example illustrates the use of the anchored objects without thehelper classes found inmpl_toolkits.axes_grid1. This versionof the figure is similar to the one found inSimple Anchored Artists, but it isimplemented using only the matplotlib namespace, without the helpof additional toolkits.
frommatplotlibimportpyplotaspltfrommatplotlib.linesimportLine2Dfrommatplotlib.offsetboximport(AnchoredOffsetbox,AuxTransformBox,DrawingArea,TextArea,VPacker)frommatplotlib.patchesimportCircle,Ellipsedefdraw_text(ax):"""Draw a text-box anchored to the upper-left corner of the figure."""box=AnchoredOffsetbox(child=TextArea("Figure 1a"),loc="upper left",frameon=True)box.patch.set_boxstyle("round,pad=0.,rounding_size=0.2")ax.add_artist(box)defdraw_circles(ax):"""Draw circles in axes coordinates."""area=DrawingArea(width=40,height=20)area.add_artist(Circle((10,10),10,fc="tab:blue"))area.add_artist(Circle((30,10),5,fc="tab:red"))box=AnchoredOffsetbox(child=area,loc="upper right",pad=0,frameon=False)ax.add_artist(box)defdraw_ellipse(ax):"""Draw an ellipse of width=0.1, height=0.15 in data coordinates."""aux_tr_box=AuxTransformBox(ax.transData)aux_tr_box.add_artist(Ellipse((0,0),width=0.1,height=0.15))box=AnchoredOffsetbox(child=aux_tr_box,loc="lower left",frameon=True)ax.add_artist(box)defdraw_sizebar(ax):""" Draw a horizontal bar with length of 0.1 in data coordinates, with a fixed label center-aligned underneath. """size=0.1text=r"1$^{\prime}$"sizebar=AuxTransformBox(ax.transData)sizebar.add_artist(Line2D([0,size],[0,0],color="black"))text=TextArea(text)packer=VPacker(children=[sizebar,text],align="center",sep=5)# separation in points.ax.add_artist(AnchoredOffsetbox(child=packer,loc="lower center",frameon=False,pad=0.1,borderpad=0.5))# paddings relative to the legend fontsize.fig,ax=plt.subplots()ax.set_aspect(1)draw_text(ax)draw_circles(ax)draw_ellipse(ax)draw_sizebar(ax)plt.show()