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charts interview questions

Top charts frequently asked interview questions

What is the best open-source java charting library? (other than jfreechart) [closed]

Why are there not more opensource easy to use charting libraries for Java?. The only successful opensource project in this area seems to be jfreechart, and it doesn't even have any documentation or examples available.


Source: (StackOverflow)

WPF chart controls [closed]

I am looking for a very simple WPF chart which should have a 2D graph and should have pan and zoom facilities .


Source: (StackOverflow)

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Hide axis and gridlines Highcharts

I am trying to hide the axis and gridlines of my Highcharts chart entirely. So far I have tried to set the width of the lines to 0, but it didn't work out.

xAxis: {
  lineWidth: 0,
  minorGridLineWidth: 0,
  lineColor: 'transparent'
}

Is it possible to just globally disable the axis lines/ticks and gridlines to create a "plain" plot?


Source: (StackOverflow)

Is there a good charting library for iPhone? [closed]

I have a need to render and display charts (bar charts for now, but more types may be needed later) in an iPhone app I'm working on. I've done some looking around and it doesn't look like there are any really good, mature charting libraries for iPhone yet. I've also looked for something written for Cocoa on the Mac that can be adapted, but haven't found anything great yet.

Anybody dealt with this before? Any recommendations?

I did find Core Plot, but it seems to be in the early stages of development.

Edit to add some details of requirements (as they currently stand ;) )

  • Bar Charts
  • Horizontal bar charts
  • Double stacked bar charts
  • Axis labels (including rotated 90 degrees on the y axis)
  • Labels above each bar on the chart
  • Shaded or custom backgrounds

Source: (StackOverflow)

PHP MySQL Google Chart JSON - Complete Example

I have searched a lot to find a good example for generating a Google Chart using MySQL table data as the data source. I searched for a couple of days and realised that there are few examples available for generating a Google Chart (pie, bar, column, table) using a combination of PHP and MySQL. I finally managed to get one example working.

I have previously received a lot of help from StackOverflow, so this time I will return some.

I have two examples; one uses Ajax and the other does not. Today, I will only show the non-Ajax example.

Usage:

    Requirements: PHP, Apache and MySQL

    Installation:

      --- Create a database by using phpMyAdmin and name it "chart"
      --- Create a table by using phpMyAdmin and name it "googlechart" and make 
          sure table has only two columns as I have used two columns. However, 
          you can use more than 2 columns if you like but you have to change the 
          code a little bit for that
      --- Specify column names as follows: "weekly_task" and "percentage"
      --- Insert some data into the table
      --- For the percentage column only use a number

          ---------------------------------
          example data: Table (googlechart)
          ---------------------------------

          weekly_task     percentage
          -----------     ----------
          Sleep           30
          Watching Movie  10
          job             40
          Exercise        20    


PHP-MySQL-JSON-Google Chart Example:

    <?php
$con=mysql_connect("localhost","Username","Password") or die("Failed to connect with database!!!!");
mysql_select_db("Database Name", $con); 
// The Chart table contains two fields: weekly_task and percentage
// This example will display a pie chart. If you need other charts such as a Bar chart, you will need to modify the code a little to make it work with bar chart and other charts
$sth = mysql_query("SELECT * FROM chart");

/*
---------------------------
example data: Table (Chart)
--------------------------
weekly_task     percentage
Sleep           30
Watching Movie  40
work            44
*/

$rows = array();
//flag is not needed
$flag = true;
$table = array();
$table['cols'] = array(

    // Labels for your chart, these represent the column titles
    // Note that one column is in "string" format and another one is in "number" format as pie chart only required "numbers" for calculating percentage and string will be used for column title
    array('label' => 'Weekly Task', 'type' => 'string'),
    array('label' => 'Percentage', 'type' => 'number')

);

$rows = array();
while($r = mysql_fetch_assoc($sth)) {
    $temp = array();
    // the following line will be used to slice the Pie chart
    $temp[] = array('v' => (string) $r['Weekly_task']); 

    // Values of each slice
    $temp[] = array('v' => (int) $r['percentage']); 
    $rows[] = array('c' => $temp);
}

$table['rows'] = $rows;
$jsonTable = json_encode($table);
//echo $jsonTable;
?>

<html>
  <head>
    <!--Load the Ajax API-->
    <script type="text/javascript" src="https://www.google.com/jsapi"></script>
    <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.2/jquery.min.js"></script>
    <script type="text/javascript">

    // Load the Visualization API and the piechart package.
    google.load('visualization', '1', {'packages':['corechart']});

    // Set a callback to run when the Google Visualization API is loaded.
    google.setOnLoadCallback(drawChart);

    function drawChart() {

      // Create our data table out of JSON data loaded from server.
      var data = new google.visualization.DataTable(<?=$jsonTable?>);
      var options = {
           title: 'My Weekly Plan',
          is3D: 'true',
          width: 800,
          height: 600
        };
      // Instantiate and draw our chart, passing in some options.
      // Do not forget to check your div ID
      var chart = new google.visualization.PieChart(document.getElementById('chart_div'));
      chart.draw(data, options);
    }
    </script>
  </head>

  <body>
    <!--this is the div that will hold the pie chart-->
    <div id="chart_div"></div>
  </body>
</html>


PHP-PDO-JSON-MySQL-Google Chart Example:

<?php
    /*
    Script  : PHP-PDO-JSON-mysql-googlechart
    Author  : Enam Hossain
    version : 1.0

    */

    /*
    --------------------------------------------------------------------
    Usage:
    --------------------------------------------------------------------

    Requirements: PHP, Apache and MySQL

    Installation:

      --- Create a database by using phpMyAdmin and name it "chart"
      --- Create a table by using phpMyAdmin and name it "googlechart" and make sure table has only two columns as I have used two columns. However, you can use more than 2 columns if you like but you have to change the code a little bit for that
      --- Specify column names as follows: "weekly_task" and "percentage"
      --- Insert some data into the table
      --- For the percentage column only use a number

          ---------------------------------
          example data: Table (googlechart)
          ---------------------------------

          weekly_task     percentage
          -----------     ----------

          Sleep           30
          Watching Movie  10
          job             40
          Exercise        20     


    */

    /* Your Database Name */
    $dbname = 'chart';

    /* Your Database User Name and Passowrd */
    $username = 'root';
    $password = '123456';

    try {
      /* Establish the database connection */
      $conn = new PDO("mysql:host=localhost;dbname=$dbname", $username, $password);
      $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

      /* select all the weekly tasks from the table googlechart */
      $result = $conn->query('SELECT * FROM googlechart');

      /*
          ---------------------------
          example data: Table (googlechart)
          --------------------------
          weekly_task     percentage
          Sleep           30
          Watching Movie  10
          job             40
          Exercise        20       
      */



      $rows = array();
      $table = array();
      $table['cols'] = array(

        // Labels for your chart, these represent the column titles.
        /* 
            note that one column is in "string" format and another one is in "number" format 
            as pie chart only required "numbers" for calculating percentage 
            and string will be used for Slice title
        */

        array('label' => 'Weekly Task', 'type' => 'string'),
        array('label' => 'Percentage', 'type' => 'number')

    );
        /* Extract the information from $result */
        foreach($result as $r) {

          $temp = array();

          // the following line will be used to slice the Pie chart

          $temp[] = array('v' => (string) $r['weekly_task']); 

          // Values of each slice

          $temp[] = array('v' => (int) $r['percentage']); 
          $rows[] = array('c' => $temp);
        }

    $table['rows'] = $rows;

    // convert data into JSON format
    $jsonTable = json_encode($table);
    //echo $jsonTable;
    } catch(PDOException $e) {
        echo 'ERROR: ' . $e->getMessage();
    }

    ?>


    <html>
      <head>
        <!--Load the Ajax API-->
        <script type="text/javascript" src="https://www.google.com/jsapi"></script>
        <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.2/jquery.min.js"></script>
        <script type="text/javascript">

        // Load the Visualization API and the piechart package.
        google.load('visualization', '1', {'packages':['corechart']});

        // Set a callback to run when the Google Visualization API is loaded.
        google.setOnLoadCallback(drawChart);

        function drawChart() {

          // Create our data table out of JSON data loaded from server.
          var data = new google.visualization.DataTable(<?=$jsonTable?>);
          var options = {
               title: 'My Weekly Plan',
              is3D: 'true',
              width: 800,
              height: 600
            };
          // Instantiate and draw our chart, passing in some options.
          // Do not forget to check your div ID
          var chart = new google.visualization.PieChart(document.getElementById('chart_div'));
          chart.draw(data, options);
        }
        </script>
      </head>

      <body>
        <!--this is the div that will hold the pie chart-->
        <div id="chart_div"></div>
      </body>
    </html>


PHP-MySQLi-JSON-Google Chart Example

<?php
/*
Script  : PHP-JSON-MySQLi-GoogleChart
Author  : Enam Hossain
version : 1.0

*/

/*
--------------------------------------------------------------------
Usage:
--------------------------------------------------------------------

Requirements: PHP, Apache and MySQL

Installation:

  --- Create a database by using phpMyAdmin and name it "chart"
  --- Create a table by using phpMyAdmin and name it "googlechart" and make sure table has only two columns as I have used two columns. However, you can use more than 2 columns if you like but you have to change the code a little bit for that
  --- Specify column names as follows: "weekly_task" and "percentage"
  --- Insert some data into the table
  --- For the percentage column only use a number

      ---------------------------------
      example data: Table (googlechart)
      ---------------------------------

      weekly_task     percentage
      -----------     ----------

      Sleep           30
      Watching Movie  10
      job             40
      Exercise        20     


*/

/* Your Database Name */

$DB_NAME = 'chart';

/* Database Host */
$DB_HOST = 'localhost';

/* Your Database User Name and Passowrd */
$DB_USER = 'root';
$DB_PASS = '123456';





  /* Establish the database connection */
  $mysqli = new mysqli($DB_HOST, $DB_USER, $DB_PASS, $DB_NAME);

  if (mysqli_connect_errno()) {
    printf("Connect failed: %s\n", mysqli_connect_error());
    exit();
  }

   /* select all the weekly tasks from the table googlechart */
  $result = $mysqli->query('SELECT * FROM googlechart');

  /*
      ---------------------------
      example data: Table (googlechart)
      --------------------------
      Weekly_Task     percentage
      Sleep           30
      Watching Movie  10
      job             40
      Exercise        20       
  */



  $rows = array();
  $table = array();
  $table['cols'] = array(

    // Labels for your chart, these represent the column titles.
    /* 
        note that one column is in "string" format and another one is in "number" format 
        as pie chart only required "numbers" for calculating percentage 
        and string will be used for Slice title
    */

    array('label' => 'Weekly Task', 'type' => 'string'),
    array('label' => 'Percentage', 'type' => 'number')

);
    /* Extract the information from $result */
    foreach($result as $r) {

      $temp = array();

      // The following line will be used to slice the Pie chart

      $temp[] = array('v' => (string) $r['weekly_task']); 

      // Values of the each slice

      $temp[] = array('v' => (int) $r['percentage']); 
      $rows[] = array('c' => $temp);
    }

$table['rows'] = $rows;

// convert data into JSON format
$jsonTable = json_encode($table);
//echo $jsonTable;


?>


<html>
  <head>
    <!--Load the Ajax API-->
    <script type="text/javascript" src="https://www.google.com/jsapi"></script>
    <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.2/jquery.min.js"></script>
    <script type="text/javascript">

    // Load the Visualization API and the piechart package.
    google.load('visualization', '1', {'packages':['corechart']});

    // Set a callback to run when the Google Visualization API is loaded.
    google.setOnLoadCallback(drawChart);

    function drawChart() {

      // Create our data table out of JSON data loaded from server.
      var data = new google.visualization.DataTable(<?=$jsonTable?>);
      var options = {
           title: 'My Weekly Plan',
          is3D: 'true',
          width: 800,
          height: 600
        };
      // Instantiate and draw our chart, passing in some options.
      // Do not forget to check your div ID
      var chart = new google.visualization.PieChart(document.getElementById('chart_div'));
      chart.draw(data, options);
    }
    </script>
  </head>

  <body>
    <!--this is the div that will hold the pie chart-->
    <div id="chart_div"></div>
  </body>
</html>

Source: (StackOverflow)

What is your preferred way to produce charts in a Ruby on Rails web application?

I'd like to add some pie, bar and scatter charts to my Ruby on Rails web application. I want want them to be atractive, easy to add and not introduce much overhead.

What charting solution would you recommend?
What are its drawbacks (requires Javascript, Flash, expensive, etc)?


Source: (StackOverflow)

Charts for Android

I am working on a project which have some charts (graphs), tick chart, candlestick chart and range chart. But the problem is, there is no library for that charts. I have got Google chart api for candlestick chart. But I don't want graph/chart in a webview. this is the link for example of candlestick chart based on Google chart api http://rpiesnikowski.blogspot.in/2011/03/android-candlestick-chart-with-google.html .


Source: (StackOverflow)

iOS chart libraries? [duplicate]

Possible Duplicate:
Is there a good charting library for iPhone?

Are there any high quality iOS chart libraries (commercial or free) available? I've found very little. Any recommendations?


Source: (StackOverflow)

.NET 3.5 chart controls exception: Error executing child request for ChartImg.axd

Anyone getting this error when using the new free chart controls MS bought from Dundas?

"Error executing child request for ChartImg.axd"

On the MSDN forum they suggested it was my web.config: MSDN forum post

So far that hasn't fixed the problem though. Any other ideas?


Source: (StackOverflow)

New asp.net charting controls - will they work with MVC (eventually)?

Scott Gu just posted about a new set of charting controls being distributed by the .NET team. They look incredible: http://weblogs.asp.net/scottgu/archive/2008/11/24/new-asp-net-charting-control-lt-asp-chart-runat-quot-server-quot-gt.aspx

The million dollar question is ... will they work with MVC, and if so, when?


Source: (StackOverflow)

How do you plot bar charts in gnuplot?

How do you plot bar charts in gnuplot with text labels?


Source: (StackOverflow)

creating charts with angularjs

I've also been looking at charting solutions that will blend well with Angular.JS directives. I came across a few but got really confused. Does anyone have any suggestions for how to create interactive charts that are integrated with Angular.JS modules?


Source: (StackOverflow)

jQuery Charting [closed]

Can anybody suggest nice cross browser jQuery API plugin for developing Chart application

except like filamentgroup.com.

The API should be customizible.I want to integrate it in ASP.NET. (ofcourse ASP.NET 3.5 comes with inbuilt Chart control,I want some nice jQuery Plugins).


Source: (StackOverflow)

Command-line Unix ASCII-based charting / plotting tool

Is there a good command-line UNIX charting / graphing / plotting tool out there? I'm looking for something that will plot xy points on an ASCII graph.

Just to clarify, I'm looking for something that will output a graph in ASCII (like ascii-art style), so I can use it over an interactive shell session without needing X.


Source: (StackOverflow)