# curvepy
A mathematical and financial function curve utility library for Python.
# Installation
With [poetry](https://python-poetry.org):
```bash
poetry add curvepy
```
Or with pip:
```
pip3 install curvepy
```
# Usage
Have a look at the [documentation](https://diatche.github.io/curvepy/).
## Basic usage:
```python
# Create a line
from curvepy import Line
line = Line(const=1, slope=2)
assert line.y(0) == 1
assert line.y(1) == 3
# Function arithmetic
line2 = Line(const=-1, slope=-2)
line_sum = line1 + line2
assert line_sum.y(0) == 0
assert line_sum.y(1) == 0
```
## JSON Format
**Function values:**
Functions are denoted by `$`, for example, `$add`. Available functions:
- `$add`: Adds values. Example: `{ "$add": [1, 2] }`, which results in `1 + 2`.
- `$line`: Adds values. Example: `{ "$line": { "points": [[1, 2], [2, 3]] } }` which results in a line joining the points `(1, 2)` and `(2, 3)`.
For other functions, refer to `Curve` documentation.
Decorators modify applicable values and functions inside of them as well as deeply nested values. Available decorators:
- `@date`: Converts all string values to seconds from Unix epoch. If no GMT offset is given, uses the local time zone at the time of parsing.
- `@log`: Converts all number literals to log space. On exit from the decorator, the result is raised bacj by the base into linear space. Available varaints: `@log2`, `@log10`.
- `@args`: Allows using both named and unamed arguments in a function. For example: `{ '$raised': { '@args': [4], 'base': 2 } }`, which will result in `pow(2, 4)`.
A full example:
The following price will be in the form of a line (on a log chart) joining the prices **10080.2** and **8975.0** on dates **8 May 2020 11:01 am** and **13 May 2020 5 am** respectively.
```json
{
"price": {
"@log": {
"$line": {
"points": [
[{"@date": "2020-05-08 11:01"}, 10080.2],
[{"@date": "2020-05-13 05:00"}, 8975.0]
]
}
}
}
}
```
# Development
## Setup
Clone repository and run:
```bash
poetry install
```
## Running Unit Tests
```bash
poetry run test
```
## Updating Documentation
The module [pdoc3](https://pdoc3.github.io/pdoc/) is used to automatically generate documentation. To update the documentation:
1. Install `pdoc3` if needed with `pip3 install pdoc3`.
2. Navigate to project root and install dependencies: `poetry install`.
3. Generate documetation files with: `pdoc3 -o docs --html curvepy`.
4. The new files will be in `docs/curvepy`. Move them to `docs/` and replace existing files.
If you get errors about missing modules, make sure you have activated the python enviroment (in .venv) and that there are no python version mismatches. If so, use `poetry env use <python version>; poetry install` to fix.
