filter by course and metro works on average

public/app.js

@@ -178,6 +178,7 @@ const populateMetrosCoursesCheckboxes = ()=>{
 		.on('click', (event, datum)=>{
 			datum.checked = !datum.checked
 			renderPoints()
+			displayMeanStandardDeviation()
 		})
 
 	d3.select('#metros ul')
@@ -194,6 +195,7 @@ const populateMetrosCoursesCheckboxes = ()=>{
 		.on('click', (event, datum)=>{
 			datum.checked = !datum.checked
 			renderPoints()
+			displayMeanStandardDeviation()
 		})
 
 	d3.select('#courses button:nth-child(2)')
@@ -202,6 +204,7 @@ const populateMetrosCoursesCheckboxes = ()=>{
 				course.checked = true
 			}
 			renderPoints()
+			displayMeanStandardDeviation()
 			populateMetrosCoursesCheckboxes()
 		})
 	d3.select('#courses button:nth-child(3)')
@@ -210,6 +213,7 @@ const populateMetrosCoursesCheckboxes = ()=>{
 				course.checked = false 
 			}
 			renderPoints()
+			displayMeanStandardDeviation()
 			populateMetrosCoursesCheckboxes()
 		})
 
@@ -219,6 +223,7 @@ const populateMetrosCoursesCheckboxes = ()=>{
 				metro.checked = true
 			}
 			renderPoints()
+			displayMeanStandardDeviation()
 			populateMetrosCoursesCheckboxes()
 		})
 	d3.select('#metros button:nth-child(3)')
@@ -227,6 +232,7 @@ const populateMetrosCoursesCheckboxes = ()=>{
 				metro.checked = false 
 			}
 			renderPoints()
+			displayMeanStandardDeviation()
 			populateMetrosCoursesCheckboxes()
 		})
 }
@@ -281,6 +287,18 @@ const getAverage = (start, end) => {
 
 const displayMeanStandardDeviation = () => {
 	sortedInstances = instances.sort((a,b) => Date.parse(a.graduation_date) - Date.parse(b.graduation_date))
+	sortedInstances = sortedInstances.filter(datum=> {
+		const instanceMetro = datum.course.split('-')[0]
+		const instanceCourse = datum.course.split('-')[1]
+		const metro = metros.find(m => m.metro === instanceMetro)
+		const course = courses.find(c => c.course === instanceCourse)
+		if(metro.checked && course.checked){
+			return true
+		} else {
+			return false
+		}
+	})
+
 	averageOutcomes = []
 	for(let i = 0; i < sortedInstances.length-10; i += 10){
 		getAverage(i,i+10)