https://github.com/brianpursley/sorting-network
Python script to check sorting networks and generate sorting network diagrams
https://github.com/brianpursley/sorting-network
comparison-network python sorting-algorithms sorting-network sorting-network-diagrams
Last synced: 5 months ago
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Python script to check sorting networks and generate sorting network diagrams
- Host: GitHub
- URL: https://github.com/brianpursley/sorting-network
- Owner: brianpursley
- License: mit
- Created: 2015-09-12T15:21:19.000Z (over 10 years ago)
- Default Branch: master
- Last Pushed: 2024-04-26T00:13:15.000Z (over 1 year ago)
- Last Synced: 2024-04-27T00:41:39.656Z (over 1 year ago)
- Topics: comparison-network, python, sorting-algorithms, sorting-network, sorting-network-diagrams
- Language: Python
- Size: 70.3 KB
- Stars: 17
- Watchers: 3
- Forks: 4
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# sorting-network
Python script to check sorting networks and generate sorting network diagrams
## Requirements
* Python 3.10 or later
## Usage
```text
usage: sortingnetwork.py [-h] [--input [inputfile]] {check,print,sort,svg} ...
a tool for working with sorting networks
positional arguments:
{check,print,sort,svg}
check check whether it is a sorting network
print print the comparison network definition
sort sort a sequence using the input comparison network
svg generate an SVG
options:
-h, --help show this help message and exit
--input [inputfile], -i [inputfile]
file containing comparison network definition, or use stdin if not specified
```
Comparison networks can be specified like this: `0:1,2:3,0:2,1:3,1:2` and can either be loaded from a file using the `--input` argument or if no input file is specified, read from stdin.
Multiple lines can be used as well, to logically group the comparators at each depth. `0:1,2:3,0:2,1:3,1:2` is the same as this:
```text
0:1,2:3
0:2,1:3
1:2
```
## Check Command
```text
usage: sortingnetwork.py check [-h] [--show-progress]
check whether it is a sorting network
options:
-h, --help show this help message and exit
--show-progress show percent complete while checking
```
* If it is a sorting network, the output will be `It is a sorting network!` and the exit code will be 0.
* If it is not a sorting network, the output will be `It is not a sorting network.` and the exit code will be 1.
You can use the `--show-progress` option to see the percent complete while it is checking.
For better performance while checking large sorting networks, the use of [pypy](https://github.com/pypy/pypy?tab=readme-ov-file) is recommended.
### Example: Check a comparison network from a file
```shell
./sortingnetwork.py --input example.cn check
```
### Example: Check a comparison network from stdin
```shell
echo "0:1,2:3,0:2,1:3,1:2" | ./sortingnetwork.py check
```
## Print Command
```text
usage: sortingnetwork.py print [-h] [filename]
print the comparison network definition
positional arguments:
filename the file to save the output to
options:
-h, --help show this help message and exit
```
* If a filename is not specified, the comparison network will be output to stdout.
### Example: Print the comparison network to a file
```shell
./sortingnetwork.py --input example.cn svg example.svg
```
### Example: Print the comparison network to stdout
```shell
./sortingnetwork.py --input example.cn svg
```
## Sort Command
```text
usage: sortingnetwork.py sort [-h] [sequence]
sort a sequence using the input comparison network
positional arguments:
sequence the sequence to sort, e.g. '3,1,2'
options:
-h, --help show this help message and exit
```
* The sequence can be a list of any types that can be compared, such as integers or strings, as long as it is parse-able.
* The number of items in the sequence must match the number of inputs in the comparison network.
### Example: Sort a sequence
```shell
./sortingnetwork.py --input example.cn sort 3,1,2
```
## SVG Command
```text
usage: sortingnetwork.py svg [-h] [filename]
generate an SVG
positional arguments:
filename the file to save the SVG to
options:
-h, --help show this help message and exit
```
* If a filename is not specified, the SVG will be output to stdout.
### Example: Generate an SVG to a file
```shell
./sortingnetwork.py --input example.cn svg example.svg
```
### Example: Generate an SVG to stdout
```shell
./sortingnetwork.py --input example.cn svg
```
### Example pipe the output through rsvg-convert to generate a PNG (or other format) instead of SVG.
(*rsvg-convert can be installed by using `sudo apt-get install librsvg2-bin` on Ubuntu.*)
```shell
./sortingnetwork.py --input example.cn svg | rsvg-convert > examples/4-input.png
```
## Example sorting networks
### 4-Input
```text
0:1,2:3
0:2,1:3
1:2
```
### 5-Input
```text
0:1,3:4
2:4
2:3,1:4
0:3
0:2,1:3
1:2
```
### 8-Input Bitonic
```text
0:1,2:3,4:5,6:7
0:3,1:2,4:7,5:6
0:1,2:3,4:5,6:7
0:7,1:6,2:5,3:4
0:2,1:3,4:6,5:7
0:1,2:3,4:5,6:7
```
### 16-Input
```text
0:1,2:3,4:5,6:7,8:9,10:11,12:13,14:15
0:2,1:3,4:6,5:7,8:10,9:11,12:14,13:15
0:4,1:5,2:6,3:7,8:12,9:13,10:14,11:15
0:8,1:9,2:10,3:11,4:12,5:13,6:14,7:15
5:10,6:9,3:12,13:14,7:11,1:2,4:8
1:4,7:13,2:8,11:14
2:4,5:6,9:10,11:13,3:8,7:12
6:8,10:12,3:5,7:9
3:4,5:6,7:8,9:10,11:12
6:7,8:9
```
See the [examples](examples) directory for more examples.
The examples provided are not necessarily the most efficient sorting networks for the given number of inputs. They are provided for illustrative purposes and testing.
## Contributors
* [brianpursley](https://github.com/brianpursley) - Original author / maintainer
* [mizar](https://github.com/mizar) - Various improvements, including an optimized `is_sorting_network()` function using a [three-valued-logic DFS approach](https://github.com/brianpursley/sorting-network/pull/9).