DashboardController.php

<?php

namespace App\Http\Controllers;

use App\EnviromentalData;
use App\Datasets\StatisticsDataset;
use App\Services\TransformService;
use Illuminate\Http\Request;

use App\Http\Requests;
use App\Http\Controllers\Controller;


class DashboardController extends Controller
{
    public function dashboard()
    {
        return view('pages.dashboard');
    }

    /*public function index()
    {
        $dataset = EnviromentalData::all();
        return TransformService::transform($dataset);
    }*/

    /**
     * Display a listing of the resource.
     *
     * @param Request $request
     * @return string
     */
    public function show(Request $request)
    {
        $from = $request->input('from');
        $to = $request->input('to');

        $envData = EnviromentalData::where('data_recorded', '>=', $from)
            ->where('data_recorded', '<=', $to)->get();

        return TransformService::transform($envData);
    }
}

EnviromentalData.php

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class EnviromentalData extends Model
{
    /**
     * The database table used by the model.
     *
     * @var string
     */
    protected $table = 'enviromental_data';

    /**
     * The attributes that are mass assignable.
     *
     * @var array
     */
    protected $fillable = ['data_recorded', 'air_temp', 'bar_press', 'wind_speed'];

    /**
     * The attributes excluded from the model's JSON form.
     *
     * @var array
     */
    protected $hidden = ['created_at', 'updated_at'];

    /**
     * The Accessor for 'air_temp' attribute
     *
     * @param $value
     * @return array
     */
    public function getAirTempAttribute($value)
    {
        return explode(',', $value);
    }

    /**
     * The Accessor for 'bar_press' attribute
     *
     * @param $value
     * @return array
     */
    public function getBarPressAttribute($value)
    {
        return explode(',', $value);
    }

    /**
     * The Accessor for 'wind_speed' attribute
     *
     * @param $value
     * @return array
     */
    public function getWindSpeedAttribute($value)
    {
        return explode(',', $value);
    }

    /**
     * The Mutator for 'air_temp' attribute
     * 
     * @param $value
     */
    public function setAirTempAttribute($value)
    {
        $this->attributes['air_temp'] = implode(',', $value);
    }

    /**
     * The Mutator for 'bar_press' attribute
     * 
     * @param $value
     */
    public function setBarPressAttribute($value)
    {
        $this->attributes['bar_press'] = implode(',', $value);
    }

    /**
     * The Mutator for 'wind_speed' attribute
     * 
     * @param $value
     */
    public function setWindSpeedAttribute($value)
    {
        $this->attributes['wind_speed'] = implode(',', $value);
    }

    /**
     * Display first date
     *
     * @return mixed
     */
    public static function getFirstDate()
    {
        $rowFirst = EnviromentalData::findOrFail(1);
        return $rowFirst->data_recorded;
    }

    /**
     * Display last date
     *
     * @return mixed
     */
    public static function getLastDate()
    {
        $rowLast = EnviromentalData::all()->last();
        return $rowLast->data_recorded;
    }
}

routes.php

scripts.js

// Ajax call to update the dashboard
    function loadChart() {

        var form = $('#dashboard-date');

        $.ajax({
            url: form.prop('action'),
            data: form.serialize(),
            method: form.prop('method'),
            dataType: 'json'
        })
        //$.getJSON(window.location.href + '/from/' + fromDate + '/to/' + toDate)
            .done(function (data, textStatus, jqXHR) {
                if(jqXHR.status === 200 ) {
                    console.log(data);

                }
            })
            .fail(function (jqXHR, textStatus, errorThrown) {

                var errorsHtml = '<div class="alert alert-danger"><ul>';

                /*if(jqXHR.status === 401 ) {
                    $( location ).prop( 'pathname', 'auth/login' );
                    var errors = data.responseJSON.msg;
                    errorsHtml = '<div class="alert alert-danger">' + errors + '</div>';
                    $( '#form-errors' ).html( errorsHtml );
                }*/

                // Laravel error message
                if (jqXHR.status === 422 ) {
                    var errors = jqXHR.responseJSON;
                    $.each(errors , function(key, value) {
                        errorsHtml += '<li>' + value[0] + '</li>';
                    });
                }

                // if not found
                /*if (jqXHR.status === 404) {
                 console.log(errorThrown);
                 //$('.alert.alert-danger').html(errorThrown);
                 }*/

                if (jqXHR.status === 500)
                {
                    if ($('#from').val() > $('#to').val()) {
                        errorsHtml += "<li>from date field can't be greater than to</li>";
                    }
                    else {
                        errorsHtml += "<li>no data for these time intervals</li>";
                    }
                }

                errorsHtml += '</ul></div>';
                $('#form-errors').html(errorsHtml);
            });
    }

StatisticsDataset.php

<?php

namespace App\Datasets;

class StatisticsDataset
{
    private $values;
    private $valuesLength;
    private $precision = 2;

    public function __construct(array $vals)
    {
        $this->values = $vals;
        sort($this->values);

        $this->valuesLength = count($vals);
    }

    public function getMedian()
    {
        $mid = $this->valuesLength * 0.5;

        if ($this->valuesLength % 2)
        {
            $median = $this->values[$mid - 0.5];
        }
        else
        {
            $median = round(($this->values[$mid - 1] + $this->values[$mid]) / 2, $this->precision);
        }

        return $median;
    }

    public function getMean()
    {
        $mean = round(array_sum($this->values) / $this->valuesLength, $this->precision);
        return $mean;
    }
}

TransformService.php

<?php

namespace App\Services;

use App\Datasets\StatisticsDataset;

class TransformService
{
    public static function transform($bigData)
    {
        $airStats = array();
        $barStats = array();
        $windStats = array();

        foreach ($bigData as $row)
        {
            $airStats = array_merge($airStats, $row['air_temp']);
            $barStats = array_merge($barStats, $row['bar_press']);
            $windStats = array_merge($windStats, $row['wind_speed']);
        }

        $airAvg = new StatisticsDataset($airStats);
        $barAvg = new StatisticsDataset($barStats);
        $windAvg = new StatisticsDataset($windStats);

        $result = array(
            'air_temp' => array(
                'mean'      => $airAvg->getMean(),
                'median'    => $airAvg->getMedian()
            ),
            'bar_press' => array(
                'mean'      => $barAvg->getMean(),
                'median'    => $barAvg->getMedian()
            ),
            'wind_speed' => array(
                'mean'      => $windAvg->getMean(),
                'median'    => $windAvg->getMedian()
            )
        );

        return $result;
    }
}