Plotting GridObjects

Inbuilt Functions

There a two ways to plot your DEMs using the provided show functions.

• The class GridObject has the inbuilt GridObject.show(), which will plot the object using matplotlib.

• To plot multiple GridObjects, use topotoolbox.show(). This util function can take multiple GridObject as arguments.

import topotoolbox as topo

dem1 = topo.load_dem("taiwan")
dem1.show()

dem2 = topo.load_dem('perfectworld')

# To increase resolution use the dpi argument. Default value is 100.
topo.show(dem1, dem2)

---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
Cell In[3], line 4
      1 dem2 = topo.load_dem('perfectworld')
      3 # To increase resolution use the dpi argument. Default value is 100.
----> 4 topo.show(dem1, dem2)

File ~/.local/lib/python3.10/site-packages/topotoolbox/utils.py:96, in show(dpi, cmap, *grid)
     94 for i, dem in enumerate(grid):
     95     ax = axes[i]
---> 96     im = ax.imshow(dem, cmap=cmap)
     97     ax.set_title(dem.name)
     98     fig.colorbar(im, ax=ax, orientation='vertical')

AttributeError: 'numpy.ndarray' object has no attribute 'imshow'

External plotting

If you want to customize your plots, use the matplotlib library. A GridObject can be passed just like a np.ndarray when plotting.

import matplotlib.pyplot as plt

fig, (ax1, ax2) = plt.subplots(1, 2, dpi=200)
ax1.imshow(dem1, cmap='terrain')
ax1.set_title(dem1.name)

ax2.imshow(dem2, cmap='terrain')
ax2.set_title('my custom plot name')

plt.tight_layout()
plt.show()