# emtrees
Tree-based machine learning classifiers for microcontroller and embedded systems.
Train in Python, then do inference on any device with support for C.
Want Naive Bayes instead? Go to [embayes](https://github.com/jonnor/embayes)
## Key features
Embedded-friendly Inference
* Portable C99 code
* No libc required
* No dynamic allocations
* Integer/fixed-point math only
* Single header file include
* Fast, sub-millisecond classification
* Memory efficient. Can run with `<100 bytes RAM`
Convenient Training
* API-compatible with [scikit-learn](http://scikit-learn.org)
* Implemented in Python 3
* C classifier accessible in Python using pybind11
[MIT licensed](./LICENSE.md)
Can be used as an open source alternative to MATLAB Classification Trees,
Decision Trees using MATLAB Coder for C/C++ code generation.
`fitctree`, `fitcensemble`, `TreeBagger`, `ClassificationEnsemble`, `CompactTreeBagger`
## Status
**Minimally useful**
* Random Forests and ExtraTrees classifiers implemented
* Tested running on AVR Atmega, ESP8266 and Linux.
* On ESP8266, 8x8 digits classify in under 0.3ms with 95%+ accuracy
* On Linux, is approx 2x faster than sklearn
## Installing
Install from PyPI
pip install emtrees --user
## Usage
1. Train your model in Python
```python
import emtrees
estimator = emtrees.RandomForest(n_estimators=10, max_depth=10)
estimator.fit(X_train, Y_train)
...
```
2. Generate C code
```python
code = estimator.output_c('sonar')
with open('sonar.h', 'w') as f:
f.write(code)
```
3. Use the C code
```c
#include <emtrees.h>
#include "sonar.h"
const int32_t length = 60;
int32_t values[length] = { ... };
const int32_t predicted_class = sonar_predict(values, length):
```
For full example code, see [examples/digits.py](./examples/digits.py)
and [emtrees.ino](./emtrees.ino)
## TODO
0.2
* Standalone example application on microcontroller
* Include emtrees.h inline in generated code
1.0
* Support returning probabilities
* Support serializing/deserializing trees
Probably
* Support sklearn GradientBoostingClassifier
* Support regression trees
* Support weighted voting
* Implement Isolation Forests (requires path/depths)
Maybe
* Support [XGBoost](https://github.com/dmlc/xgboost) learning of trees
* Support [LightGBM](https://github.com/Microsoft/LightGBM) learning of trees
* Support [CatBoost](https://github.com/catboost/catboost) learning of trees
* Support/Implement a Very Fast Decision Tree (VFDT) learning algorithm
* Implement multithreading when used in Python bindings, using OpenMP
