https://github.com/linkedin/featurefu
Library and tools for advanced feature engineering
https://github.com/linkedin/featurefu
Last synced: 5 months ago
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Library and tools for advanced feature engineering
- Host: GitHub
- URL: https://github.com/linkedin/featurefu
- Owner: linkedin
- License: apache-2.0
- Created: 2015-04-21T23:26:41.000Z (over 10 years ago)
- Default Branch: master
- Last Pushed: 2020-12-16T22:34:16.000Z (about 5 years ago)
- Last Synced: 2024-04-13T23:22:26.089Z (almost 2 years ago)
- Language: Java
- Homepage:
- Size: 172 KB
- Stars: 564
- Watchers: 79
- Forks: 109
- Open Issues: 2
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
FeatureFu
======
FeatureFu[l] contains a collection of library/tools for advanced feature engineering, such as using extended s-expression based feature transformation, to derive features on top of other features, or convert a light weighted model (logistical regression or decision tree) into a feature, in an intuitive way without touching any code.
Sample use cases:
1. Feature normalization
"(min 1 (max (+ (* slope x) intercept) 0))" : scale feature x with slope and intercept, and normalize to [0,1]
2. Feature combination
"(‐ (log2 (+ 5 impressions)) (log2 (+ 1 clicks)))" : combine #impression and #clicks into a smoothed CTR style feature
3. Nonlinear featurization
"(if (> query_doc_matches 0) 0 1)" : negation of a query/document matching feature
4. Cascading modeling
"(sigmoid (+ (+ (..) w1) w0))" : convert a logistic regression model into a feature
5. Model combination (e.g. combine decision tree and linear regression)
"(+ (* model1_score w1) (* model2_score w2))" : combine two model scores into one final score
Expr: A super fast and simple evaluator for mathematical s-expressions written in Java.
Using it is as simple as:
```java
VariableRegistry variableRegistry=new VariableRegistry();
Expr expression = Expression.parse("(sigmoid (+ (* a x) b))",variableRegistry);
Variable x = variableRegistry.findVariable("x");
Variable a = variableRegistry.findVariable("a");
Variable b = variableRegistry.findVariable("b");
expression.evaluate();
Map varMap = new HashMap();
varMap.put("x",0.2);
varMap.put("a",0.6);
varMap.put("b",0.8);
variableRegistry.refresh(varMap);
expression.evaluate();
```
## To Build
gradle clean build
##Test
```java
cd build/expr/lib
$java -cp expr-1.0.jar Expression "(+ 0.5 (* (/ 15 1000) (ln (- 55 12))))"
=(0.5+((15.0/1000.0)*ln((55.0-12.0))))
=0.5564180017354035
tree
└── +
├── 0.5
└── *
├── /
| ├── 15.0
| └── 1000.0
└── ln
└── -
├── 55.0
└── 12.0
```
## Maven
expr is available under:
com.linkedin.featurefu
expr
0.0.3
## Gradle
dependencies {
compile "com.linkedin.featurefu:expr:0.0.3"
}