Rename (xVariable, yVariable) -> (xs, ys)

jsbean · jsbean · commit 95efaec8dc8b · 2016-11-08T20:50:52.000-05:00
diff --git a/Linear Regression/LinearRegression.playground/Contents.swift b/Linear Regression/LinearRegression.playground/Contents.swift
@@ -37,11 +37,11 @@ func multiply(_ a: [Double], _ b: [Double]) -> [Double] {
     return zip(a,b).map { $0.0 * $0.1 }
 }
 
-func linearRegression(_ xVariable: [Double], _ yVariable: [Double]) -> ((Double) -> Double) {
-    let sum1 = average(multiply(yVariable, xVariable)) - average(xVariable) * average(yVariable)
-    let sum2 = average(multiply(xVariable, xVariable)) - pow(average(xVariable), 2)
+func linearRegression(_ xs: [Double], _ ys: [Double]) -> ((Double) -> Double) {
+    let sum1 = average(multiply(ys, xs)) - average(xs) * average(ys)
+    let sum2 = average(multiply(xs, xs)) - pow(average(xs), 2)
     let slope = sum1 / sum2
-    let intercept = average(yVariable) - slope * average(xVariable)
+    let intercept = average(ys) - slope * average(xs)
     return { intercept + slope * $0 }
 }
 

Original file line number	Diff line number	Diff line change
`@@ -37,11 +37,11 @@ func multiply(_ a: [Double], _ b: [Double]) -> [Double] {`
`37`	`37`	`return zip(a,b).map { $0.0 * $0.1 }`
`38`	`38`	`}`
`39`	`39`
`40`		`-func linearRegression(_ xVariable: [Double], _ yVariable: [Double]) -> ((Double) -> Double) {`
`41`		`- let sum1 = average(multiply(yVariable, xVariable)) - average(xVariable) * average(yVariable)`
`42`		`- let sum2 = average(multiply(xVariable, xVariable)) - pow(average(xVariable), 2)`
	`40`	`+func linearRegression(_ xs: [Double], _ ys: [Double]) -> ((Double) -> Double) {`
	`41`	`+ let sum1 = average(multiply(ys, xs)) - average(xs) * average(ys)`
	`42`	`+ let sum2 = average(multiply(xs, xs)) - pow(average(xs), 2)`
`43`	`43`	`let slope = sum1 / sum2`
`44`		`- let intercept = average(yVariable) - slope * average(xVariable)`
	`44`	`+ let intercept = average(ys) - slope * average(xs)`
`45`	`45`	`return { intercept + slope * $0 }`
`46`	`46`	`}`
`47`	`47`