adding example draft

Author: MayaGans

src/dataforge/data-forge-real-world.js

@@ -0,0 +1,42 @@
+const fs = require('fs')
+const papa = require('papaparse')
+const DF = require('data-forge');
+const DataManager = require('../dataman/data-manager.js');
+
+class JSONtoDataFrame {
+
+    constructor (filename) {
+        const raw = fs.readFileSync(filename, 'utf-8')
+        const options = {header: true, dynamicTyping: true}
+        this.data = papa.parse(raw, options).data
+      }
+    
+}
+
+const temp = new JSONtoDataFrame('../../data/national_parks.csv')
+const nps = new DF.DataFrame(temp.data)
+
+const npsCleaned = nps
+         .where(row => row.year !== "Total")
+         .where(row => row.visitors !== "NA")
+         // now we can turn those columns into integers rather than strings
+
+console.log(npsCleaned.toString())
+const typesDf = npsCleaned.detectTypes(); 
+//console.log(npsCleaned.detectTypes().toString())
+
+const distinctDf = npsCleaned.dropSeries(['gnis_id', 'geometry', 'metadata', 'number_of_records', 'parkname',
+'region', 'state', 'unit_code', 'unit_name', 'unit_type', 'visitors'])
+// console.log(distinctDf.toString())
+
+const annualVisitors = npsCleaned
+    .groupBy(row => row.year)
+    .select(group => ({
+        // we will use the unique year values
+        // to populate the rows of the Year column
+        Year: group.first().year,
+        // Now we can sum the annual visitors
+        Total: group.select(row => row.visitors).sum(),
+    }))
+    .inflate()
+console.log(annualVisitors.toString())