# Random Mandala Python package
***Anton Antonov***
[Python-packages at GitHub/antononcube](https://github.com/antononcube/Python-packages)
***November 2021***
***February 2022***
## Introduction
This Python package implements the function `random_mandala` that generates plots (and images) of random mandalas.
The design, implementation *strategy*, and unit tests closely resemble the Wolfram Repository Function (WFR)
[`RandomMandala`](https://resources.wolframcloud.com/FunctionRepository/resources/RandomMandala),
[AAf1].
(Another, very similar function at WFR is
[`RandomScribble`](https://resources.wolframcloud.com/FunctionRepository/resources/RandomScribble), [AAf2].)
The Bezier mandala seeds are created using the Python package
[`bezier`](https://pypi.org/project/bezier/),
[DHp1].
For detailed descriptions of Machine Learning studies that use collections of random mandalas see the articles
[AA1, AA2].
------
## Installation
To install from GitHub use the shell command:
```shell
python -m pip install git+https://github.com/antononcube/Python-packages.git#egg=RandomMandala\&subdirectory=RandomMandala
```
To install from PyPI:
```shell
python -m pip install RandomMandala
```
------
## Details and arguments
- The mandalas made by `random_mandala` are generated through rotational symmetry of a “seed segment”.
- The function `random_mandala` returns `matplotlib` figures (objects of type `matplotlib.figure.Figure`)
- The function `random_mandala` can be given arguments of the creation function `matplotlib.pyplot.figure`.
- If `n_rows` and `n_columns` are `None` a `matplotlib` figure object with one axes object is returned.
- There are two modes of making random mandalas: (i) single-mandala mode and (ii) multi-mandala mode. The multi-mandala mode is activated by giving the `radius` argument a list of positive numbers.
- If the argument `radius` is a list of positive reals, then a "multi-mandala" is created
with the mandalas corresponding to each number in the radius list being overlain.
- Here are brief descriptions of the arguments:
- `n_rows`: Number of rows in the result figure.
- `n_columns`: Number of columns in the result figure.
- `radius`: Radius for the mandalas, a flot or a list of floats. If a list of floats the mandalas are overlain.
- `rotational_symmetry_order`: Number of copies of the seed segment that comprise the mandala.
- `connecting_function`: Connecting function, one of "line", "fill", "bezier", "bezier_fill", "random", or `None`. If 'random' or `None` a random choice of the rest of values is made.
- `number_of_elements`: Controls how may graphics elements are in the seed segment.
- `symmetric_seed`: Specifies should the seed segment be symmetric or not.
If 'random' of None random choice between `True` and `False` is made.
- `face_color`: Face (fill) color.
- `edge_color`: Edge (line) color.
-----
## Examples
Load the package `RandomMandala`, `matplotlib`, and `PIL`:
```python
from RandomMandala import random_mandala, figure_to_image
import matplotlib
import matplotlib.pyplot as plt
import matplotlib.cm
from PIL import Image, ImageOps
from mpl_toolkits.axes_grid1 import ImageGrid
import random
```
Here we generate a random mandala:
```python
random.seed(99)
fig = random_mandala()
```

Here we generate a figure with 12 (3x4) random mandalas:
```python
random.seed(33)
fig2 = random_mandala(n_rows=3, n_columns=4, figsize=(6,6))
fig2.tight_layout()
plt.show()
```

------
## Arguments details
### n_rows, n_columns
With the argument `n_rows` and `n_columns` are specified the number of rows and columns respectively in the figure object; `n_rows * n_columns` mandalas are generated:
```python
random.seed(22)
fig=random_mandala(n_rows=1, n_columns=3)
```

### connecting_function
The argument `connecting_function` specifies which graphics primitives to be used over the seed segment points:
```python
fig = matplotlib.pyplot.figure(figsize=(6, 6), dpi=120)
k = 1
for cf in ['line', 'fill', 'bezier', 'bezier_fill', 'random', None]:
random.seed(667)
fig = random_mandala(connecting_function=cf,
figure=fig,
location=(2, 3, k))
ax = fig.axes[-1]
ax.set_title(str(cf))
k = k + 1
plt.show()
plt.close(fig)
```

With values `None` or `"random"` a random choice is made from `['line', 'fill', 'bezier', 'bezier_fill']`.
### radius
In single-mandala mode the argument `radius` specifies the radius of the seed segment and the mandala:
```python
fig = matplotlib.pyplot.figure(figsize=(8, 4), dpi=120)
k = 1
for r in [5, 10, 15, 20]:
random.seed(2)
fig = random_mandala(connecting_function="line",
radius=r,
figure = fig,
location = (1, 4, k))
ax = fig.axes[-1]
ax.set_title("radius:" + str(r))
ax.axis("on")
k = k + 1
plt.show()
plt.close(fig)
```

If the value given to `radius` is a list of positive numbers then multi-mandala mode is used.
If `radius=[r[0],...,r[k]]`, then for each `r[i]` is made a mandala with radius `r[i]` and the mandalas are drawn upon each other according to their radii order:
```python
random.seed(99)
fig3=random_mandala(radius=[8,5,3],
face_color=["blue", "green", 'red'],
connecting_function="fill")
```

**Remark:** The code above used different colors for the different radii.
### rotational_symmetry_order
The argument `rotational_symmetry_order` specifies how many copies of the seed segment comprise the mandala:
```python
fig = matplotlib.pyplot.figure(figsize=(6, 12), dpi=120)
k = 1
for rso in [2, 3, 4, 6]:
random.seed(122)
fig = random_mandala(connecting_function="fill",
symmetric_seed=True,
rotational_symmetry_order=rso,
figure = fig,
location = (1, 4, k))
ax = fig.axes[-1]
ax.set_title("order:" + str(rso))
k = k + 1
plt.show()
plt.close(fig)
```

### number_of_elements
The argument `number_of_elements` controls how may graphics elements are in the seed segment:
```python
fig = matplotlib.pyplot.figure(figsize=(6, 6), dpi=120)
k = 1
for ne in [2, 3, 4, 5, 6, 12]:
random.seed(2)
fig = random_mandala(connecting_function="line",
symmetric_seed=True,
rotationa_symmetry_order=6,
number_of_elements=ne,
figure = fig,
location = (2, 3, k))
ax = fig.axes[-1]
ax.set_title("n:" + str(ne))
k = k + 1
plt.show()
plt.close(fig)
```

```python
fig = matplotlib.pyplot.figure(figsize=(4, 4), dpi=120)
k = 1
for ne in [5, 10, 15, 20]:
random.seed(26)
fig = random_mandala(connecting_function="bezier",
radius=[1],
symmetric_seed=True,
rotationa_symmetry_order=6,
number_of_elements=ne,
figure = fig,
location = (2, 2, k))
ax = fig.axes[-1]
ax.set_title("n:" + str(ne))
k = k + 1
plt.show()
plt.close(fig)
```

### symmetric_seed
The argument `symmetric_seed` specifies should the seed segment be symmetric or not:
```python
fig = matplotlib.pyplot.figure(figsize=(4, 4), dpi=120)
k = 1
for ssd in [True, False]:
random.seed(2)
fig = random_mandala(connecting_function="fill",
symmetric_seed=ssd,
figure = fig,
location = (1, 2, k))
ax = fig.axes[-1]
ax.set_title(str(ssd))
k = k + 1
plt.show()
plt.close(fig)
```

### face_color and edge_color
The arguments `face_color` and `edge_color` take as values strings or list of strings that specify the coloring of the filled-in polygons and lines respectively:
```python
fig = matplotlib.pyplot.figure(figsize=(6,3), dpi=120)
k = 1
for fc in [["0.8", "0.6", "0.2"], ["olive", "gold", "red"]]:
random.seed(11)
fig = random_mandala(radius=[10,6,4],
connecting_function="bezier_fill",
symmetric_seed=True,
face_color=fc,
figure = fig,
location = (1, 2, k))
ax = fig.axes[-1]
ax.set_title(str(fc))
k = k + 1
plt.show()
plt.close(fig)
```

### alpha
The argument `alpha` controls the opacity of the plots; it takes as values `None` and floats between 0 and 1.
```python
fig = matplotlib.pyplot.figure(figsize=(6,3), dpi=120)
k = 1
for al in [None, 0.2, 1.0]:
random.seed(23)
fig = random_mandala(radius=[10,6,4],
connecting_function="bezier_fill",
symmetric_seed=True,
alpha=al,
color_mapper=matplotlib.cm.rainbow_r,
figure = fig,
location = (1, 3, k))
ax = fig.axes[-1]
ax.set_title(str(al))
k = k + 1
plt.show()
plt.close(fig)
```

### color_mapper
The argument `color_mapper` takes as values `None` and `matplotlib.colors.Colormap` objects.
See the color mappers in the reference page ["color example code: colormaps_reference.py"](https://matplotlib.org/2.0.2/examples/color/colormaps_reference.html).
If `color_mapper` is specified then the arguments `face_color` and `edge_color` are ignored.
Here is an example using two color mappers:
```python
fig = matplotlib.pyplot.figure(figsize=(6,3), dpi=120)
cMappers=[matplotlib.cm.rainbow_r, matplotlib.cm.Accent_r]
cMappersNames=["rainbow_r", "Accent_r"]
for k in range(2):
random.seed(15)
fig = random_mandala(radius=[10,6,4],
connecting_function="bezier_fill",
symmetric_seed=True,
color_mapper=cMappers[k],
figure = fig,
location = (1, 2, k+1))
ax = fig.axes[-1]
ax.set_title(cMappersNames[k])
plt.show()
plt.close(fig)
```

------
## Applications
### Generate a collection of images
In certain Machine Learning (ML) studies it can be useful to be able to generate large enough collections of (random) images.
In the code block below we:
- Generate 64 random mandala *plots*
- Convert them into `PIL` images using the package function `figure_to_image`
- Invert and binarize images
- Plot the images in an image grid
```python
# A list to accumulate random mandala images
mandala_images = []
# Generation loop
random.seed(443)
for i in range(64):
# Generate one random mandala figure
fig2 = random_mandala(n_rows=None,
n_columns=None,
radius=[8, 6, 3],
rotational_symmetry_order=6,
symmetric_seed=True,
connecting_function='random',
face_color="0.")
fig2.tight_layout()
# Convert the figure into an image and add it to the list
mandala_images = mandala_images + [figure_to_image(fig2)]
# Close figure to save memoru
plt.close(fig2)
# Invert image colors
mandala_images2 = [ImageOps.invert(img) for img in mandala_images]
# Binarize images
mandala_images3 = [im.convert('1') for im in mandala_images2]
# Make a grid of images and display it
fig3 = plt.figure(figsize=(14., 14.))
grid = ImageGrid(fig3, 111,
nrows_ncols=(8, 8),
axes_pad=0.02,
)
for ax, img in zip(grid, mandala_images3):
ax.imshow(img)
ax.set(xticks=[], yticks=[])
plt.show()
```

## Neat examples
### A table of random mandalas
```python
random.seed(124)
fig=random_mandala(n_rows=6, n_columns=6, figsize=(10,10), dpi=240)
```

## A table of colorized mandalas
```python
fig = matplotlib.pyplot.figure(figsize=(10, 10), dpi=120)
k = 1
random.seed(56)
for i in range(36):
rs=list(range(1,random.choice([3,4,5,6])+1))
rs.sort()
rs.reverse()
fig = random_mandala(connecting_function="bezier_fill",
color_mapper=matplotlib.cm.gist_earth,
symmetric_seed=True,
radius=rs,
rotational_symmetry_order=random.choice([3,4,5,6,7]),
number_of_elements=random.choice([2,3,4]),
figure=fig,
location=(6, 6, k))
ax = fig.axes[-1]
ax.set_axis_off()
k = k + 1
fig.tight_layout()
plt.show()
plt.close(fig)
```

### A table of open colorized mandalas
```python
fig = matplotlib.pyplot.figure(figsize=(10, 10), dpi=120)
k = 1
random.seed(883)
for rso in [2 * random.random() + 2 for _ in range(36)]:
random.seed(33)
fig = random_mandala(connecting_function="bezier_fill",
radius=3,
face_color="darkblue",
rotational_symmetry_order=rso,
number_of_elements=8,
figure=fig,
location=(6, 6, k))
ax = fig.axes[-1]
ax.set_axis_off()
k = k + 1
plt.show()
plt.close(fig)
```

------
## Acknowledgements
- [Johannes Huessy](https://github.com/jhuessy) for discussing different design elements.
- [Mr.T](https://stackoverflow.com/users/8881141/mr-t) for
[figuring out and explaining the opacity argument implementation](https://stackoverflow.com/a/71267997/14163984).
------
## References
### Articles
[AA1] Anton Antonov,
["Comparison of dimension reduction algorithms over mandala images generation"](https://mathematicaforprediction.wordpress.com/2017/02/10/comparison-of-dimension-reduction-algorithms-over-mandala-images-generation/),
(2017),
[MathematicaForPrediction