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 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]}")

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

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)

# Some comparisons between the two generated GridObjects
topo.show(dem1, dem2, dem1 > dem2, dem1 == dem2)

---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
Cell In[3], line 5
      2 dem2 = topo.gen_random(rows=32, columns=32, hillsize=32)
      4 # Some comparisons between the two generated GridObjects
----> 5 topo.show(dem1, dem2, dem1 > dem2, 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'

Using AND, OR as well as XOR

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


topo.show(dem1, dem2, dem1 & dem2, dem1 | dem2, dem1 ^ dem2)

---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
Cell In[4], line 5
      1 dem1 = topo.gen_random_bool()
      2 dem2 = topo.gen_random_bool()
----> 5 topo.show(dem1, dem2, dem1 & dem2, dem1 | dem2, 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'

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

# Adding two GridObject together and multiplying dem1 by 2. Notice the colorbar
topo.show(dem1, dem2, dem1 + dem2, dem1*2)

---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
Cell In[5], line 5
      2 dem2 = topo.gen_random(rows=32, columns=32, seed=84, name='dem2')
      4 # Adding two GridObject together and multiplying dem1 by 2. Notice the colorbar
----> 5 topo.show(dem1, dem2, dem1 + dem2, dem1*2)

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'