Interaction between GridObjects

In this Jupyter Notebook, the magic functions of the gridObject are explained. These are operations like adding two GridObjects together. Instead of utilizing functions that could look like new_dem = topo.add(dem1, dem2), this package utilizes magic functions. The same addition will therefor look like this: new_dem = dem1 + dem2.

The following operations are possible using GridObjects:

• Equality Check: ==

• Inequality Check: !=

• Greater Than: >

• Less Than: <

• Greater Than or Equal To: >=

• Less Than or Equal To: <=

• Addition: +

• Subtraction: -

• Multiplication: *

• Division: /

• Logical AND: &

• Logical OR: |

• Logical XOR: ^

• Length: len()

• Iteration: for i in dem:

• Item Access: y = dem[x]

• Item Assignment: dem[x] = y

• Array Representation: Passing the GridObject in places where a numpy.ndarray is expected

• String Representation: print(dem)

import topotoolbox as topo
import matplotlib.pyplot as plt
from mpl_toolkits.axes_grid1 import make_axes_locatable
import numpy as np

Iterating through a GridObject:

dem = topo.gen_random_bool(rows=4, columns=4)

# looping through a GridObject
for i in dem:
    print(i)

# Accessing cells of an GridObject
print(f"\n{dem[2][2]}")
dem[2][2] = 2
print(f"\n{dem[2][2]}")

[1. 0. 0. 1.]
[0. 1. 0. 0.]
[1. 1. 1. 0.]
[1. 1. 0. 1.]

1.0

2.0

Comparing GridObjects

dem1 = topo.gen_random(rows=32, columns=32, hillsize=24)
dem2 = topo.gen_random(rows=32, columns=32, hillsize=32)

dem3 = dem1 > dem2
dem4 = dem1 == dem2

# Some comparisons between the two generated GridObjects
fig,axs = plt.subplots(1,4,figsize=(20,5),squeeze=False)
img1 = dem1.plot(axs[0,0],cmap="terrain")
div1 = make_axes_locatable(axs[0,0])
cax1 = div1.append_axes("right", size="5%", pad=0.05)
fig.colorbar(img1,cax=cax1)

img2 = dem2.plot(axs[0,1],cmap="terrain")
div2 = make_axes_locatable(axs[0,1])
cax2 = div2.append_axes("right", size="5%", pad=0.05)
fig.colorbar(img2,cax=cax2)

img3 = dem3.plot(axs[0,2],cmap="Greys")
div3 = make_axes_locatable(axs[0,2])
cax3 = div3.append_axes("right", size="5%", pad=0.05)
fig.colorbar(img3,cax=cax3)

img4 = dem4.plot(axs[0,3],cmap="Greys")
div4 = make_axes_locatable(axs[0,3])
cax4 = div4.append_axes("right", size="5%", pad=0.05)
fig.colorbar(img4,cax=cax4)

plt.tight_layout()

Using AND, OR as well as XOR

dem1 = topo.gen_random_bool()
dem2 = topo.gen_random_bool()

dem3 = dem1 & dem2
dem4 = dem1 | dem2
dem5 = dem1 ^ dem2

fig,axs = plt.subplots(1,5,figsize=(25,5),squeeze=False)
img1 = dem1.plot(axs[0,0],cmap="Greys")
div1 = make_axes_locatable(axs[0,0])
cax1 = div1.append_axes("right", size="5%", pad=0.05)
fig.colorbar(img1,cax=cax1)

img2 = dem2.plot(axs[0,1],cmap="Greys")
div2 = make_axes_locatable(axs[0,1])
cax2 = div2.append_axes("right", size="5%", pad=0.05)
fig.colorbar(img2,cax=cax2)

img3 = dem3.plot(axs[0,2],cmap="Greys")
div3 = make_axes_locatable(axs[0,2])
cax3 = div3.append_axes("right", size="5%", pad=0.05)
fig.colorbar(img3,cax=cax3)

img4 = dem4.plot(axs[0,3],cmap="Greys")
div4 = make_axes_locatable(axs[0,3])
cax4 = div4.append_axes("right", size="5%", pad=0.05)
fig.colorbar(img4,cax=cax4)

img5 = dem4.plot(axs[0,4],cmap="Greys")
div5 = make_axes_locatable(axs[0,4])
cax5 = div5.append_axes("right", size="5%", pad=0.05)
fig.colorbar(img5,cax=cax5)

plt.tight_layout()

dem1 = topo.gen_random(rows=32, columns=32, seed=128, name='dem1')
dem2 = topo.gen_random(rows=32, columns=32, seed=84, name='dem2')

dem3 = dem1 + dem2
dem4 = dem1 * 2

# Adding two GridObject together and multiplying dem1 by 2. Notice the colorbar
fig,axs = plt.subplots(1,4,figsize=(20,5),squeeze=False)
img1 = dem1.plot(axs[0,0],cmap="terrain")
div1 = make_axes_locatable(axs[0,0])
cax1 = div1.append_axes("right", size="5%", pad=0.05)
fig.colorbar(img1,cax=cax1)

img2 = dem2.plot(axs[0,1],cmap="terrain")
div2 = make_axes_locatable(axs[0,1])
cax2 = div2.append_axes("right", size="5%", pad=0.05)
fig.colorbar(img2,cax=cax2)

img3 = dem3.plot(axs[0,2],cmap="terrain")
div3 = make_axes_locatable(axs[0,2])
cax3 = div3.append_axes("right", size="5%", pad=0.05)
fig.colorbar(img3,cax=cax3)

img4 = dem4.plot(axs[0,3],cmap="terrain")
div4 = make_axes_locatable(axs[0,3])
cax4 = div4.append_axes("right", size="5%", pad=0.05)
fig.colorbar(img4,cax=cax4)

plt.tight_layout()