From 373010be532616b89f4c3e9fef0a972f7cf539f5 Mon Sep 17 00:00:00 2001
From: marwolaethblack <a.unal677@gmail.com>
Date: Thu, 30 Nov 2017 12:34:56 +0100
Subject: aqi

---
 src/AppBundle/Utils/Aqi.php | 43 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)
 create mode 100644 src/AppBundle/Utils/Aqi.php

(limited to 'src/AppBundle/Utils/Aqi.php')

diff --git a/src/AppBundle/Utils/Aqi.php b/src/AppBundle/Utils/Aqi.php
new file mode 100644
index 0000000..6451c77
--- /dev/null
+++ b/src/AppBundle/Utils/Aqi.php
@@ -0,0 +1,43 @@
+<?php
+/**
+ * Created by PhpStorm.
+ * User: andy
+ * Date: 11/30/17
+ * Time: 11:27 AM
+ *
+ *
+ */
+
+Namespace AppBundle\Utils;
+
+class Aqi {
+    public function calculateAQI($gasName, $concentration, $table) {
+        $bpLow = 1;
+        $bpHi = 2;
+        $bpLowIndex = 1;
+        $bpHiIndex = 1;
+
+        $arr = $table ->{$gasName} ->{'breakpoints'};
+        foreach ($arr as $index => $value) {
+            if ($value < $concentration && $table->{$gasName}->{'breakpoints'}[$index + 1] > $concentration) {
+                $bpLow = $value;
+                $bpLowIndex = $index;
+            }
+
+            if ($value > $concentration && $table->{$gasName}->{'breakpoints'}[$index - 1] < $concentration) {
+                $bpHi = $value;
+                $bpHiIndex = $index;
+            }
+
+        };
+
+
+
+        $airQualityIndex = (($table->{$gasName}->{'aq'}[$bpHiIndex] - $table->{$gasName}->{'aq'}[$bpLowIndex]) / ($bpHi - $bpLow)) * ($concentration - $bpLow) + $table->{$gasName}->{'aq'}[$bpLowIndex];
+
+        return $airQualityIndex;
+
+    }
+}
+
+?>
\ No newline at end of file
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