Add documentation for Kullback-Leibler divergence (#239)

Shashi456 · rxwei · commit 1b3f7c9231ca · 2019-06-14T08:57:55.000-07:00
diff --git a/Sources/TensorFlow/Loss.swift b/Sources/TensorFlow/Loss.swift
@@ -153,7 +153,8 @@ public func poissonLoss<Scalar: TensorFlowFloatingPoint>(
     return (predicted - expected * log(predicted)).mean()
 }
 
-/// Returns the Kullback-Leibler divergence between predictions and expectations.
+/// Returns the Kullback-Leibler divergence (KL divergence) between between expectations and predictions.
+/// Given two distributions `p` and `q`, KL divergence computes `(p * log(p / q)).sum()`.
 ///
 /// - Parameters:
 ///   - predicted: Predicted outputs from a neural network.

Original file line number	Diff line number	Diff line change
`@@ -153,7 +153,8 @@ public func poissonLoss<Scalar: TensorFlowFloatingPoint>(`
`153`	`153`	`return (predicted - expected * log(predicted)).mean()`
`154`	`154`	`}`
`155`	`155`
`156`		`-/// Returns the Kullback-Leibler divergence between predictions and expectations.`
	`156`	`+/// Returns the Kullback-Leibler divergence (KL divergence) between between expectations and predictions.`
	`157`	+/// Given two distributions `p` and `q`, KL divergence computes `(p * log(p / q)).sum()`.
`157`	`158`	`///`
`158`	`159`	`/// - Parameters:`
`159`	`160`	`/// - predicted: Predicted outputs from a neural network.`