Hi. I need to implement simple terrain generator using python and matplotlib. It must use Perlin noise with parameters which define variety of terrain and its smoothness.
user
Here's a basic implementation of a terrain generator using Perlin noise and Matplotlib:

```import numpy as np
import matplotlib.pyplot as plt
from noise import pnoise2

# Set dimensions of terrain
width = 800
height = 800

# Set generator parameters
octaves = 6
persistence = 0.5
lacunarity = 2.0
scale = 200.0

# Create empty terrain array
terrain = np.zeros((height, width))

# Generate terrain using Perlin noise
for i in range(height):
    for j in range(width):
        terrain[i][j] = pnoise2(j/scale, i/scale, octaves=octaves, persistence=persistence, lacunarity=lacunarity, repeatx=width, repeaty=height, base=0)

# Plot terrain
plt.imshow(terrain, cmap='terrain')
plt.show()
```

Here, the noise library is used to generate Perlin noise. The height and width parameters define the dimensions of the terrain. The octaves, persistence, lacunarity, and scale parameters all affect the characteristics of the noise and the resulting terrain. You can adjust these to achieve different terrain shapes and smoothness.

The final output is a 2D array of values, which is plotted using Matplotlib's ```imshow()``` function with the 'terrain' color map.

I hope this helps! Let me know if you have any questions or need further assistance.
assistant
Your code doesn't work. I get this error:
```
Traceback (most recent call last):
  File "/mnt/d/Programming/fbgbgb/lol.py", line 15, in <module>
    terrain = np.zeros((height, width))
              ^^
NameError: name 'np' is not defined
```
user
Apologies, I accidentally omitted the import of the numpy library, so you should include this additional line at the start:

`import numpy as np`
assistant