January 19, 2012

Tutorial: Update Google Charts Candlestick with a button

0 comments
To update you Google Chart Candlestick with a button, you need to add this code block at the end of the drawVisialization function if you follow this code layout: code.google.com/apis/chart/interactive/docs/gallery/candlestickchart.html

HTML
//This is the button
<input type="button" value="Next day" id="next_day" />

Javascript
//This is the end of the original javascript function, put the new code block after this line
chart.draw(data, options);


//This is the code block you need
document.getElementById('next_day').onclick = function () {

//This is the new array, it replaces the original array
var dataArray = [["", 31, 38, 55, 66]];

var data = google.visualization.arrayToDataTable(dataArray, true);

//Redraw the chart
chart.draw(data, options);
};

January 18, 2012

Tutorial: Connect Google Charts Candlestick with php

3 comments
This is a tutorial on how to connect Google Charts with php. Google already has a tutorial on this, but it's not enough and it doesn't cover areas such as candlestick charts. You can see that tutorial here: code.google.com/apis/chart/interactive/docs/php_example.html

Page 1. The main page where the chart is shown
This is a candlestick chart as in: code.google.com/apis/chart/interactive/docs/gallery/candlestickchart.html

<!-- This is where the chart is displayed -->
<div id="chart_div" style="width: 900px; height: 500px;"></div>

<!--Load jQuery (needed for $.ajax) -->
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script>
    
<!--Load the AJAX API-->
<script src="https://www.google.com/jsapi"></script>

<script>

//Load the Visualization API and the candlestick package. 1.0 is always the current production version
google.load('visualization', '1.0', {packages: ['corechart']});
    
    
function drawVisualization() {

//Get data to the table from php returns dataArray which is a javascript array
$.ajax({
url: "http://www.yoursite.com/getData.php",
dataType: "script",
async: false
});

//Create the data table. 'false' means that the first column is a label column
var data = google.visualization.arrayToDataTable(dataArray, true);

//Set chart options.
var options = {
legend: 'none',
colors: ['green'],
chartArea: {width: '95%', height: '95%'},
enableInteractivity: false,
vAxis: {textPosition: 'none'},
reverseCategories: true
};

//Instantiate an instance of the chart class
var chart = new google.visualization.CandlestickChart(document.getElementById('chart_div'));

//Draw the chart
chart.draw(data, options);

}

//Set a callback to run when the Google Visualization API is loaded. Runs the drawVisualization function
google.setOnLoadCallback(drawVisualization);
    
</script>

Page 2. Get data - getData.php
It only shows the javascript array you need - not how to get the values from a file.

<?php
//This is the basic javascript array you need
echo '
var dataArray = [
["", 20, 28, 38, 45],
["", 31, 38, 55, 66],
["", 31, 38, 55, 66]
];
';
?>

But if you need to combine javascript and php, you can do something like this to get the same result as above

<?php
//Create the javascript array from a php array
$row = 1;

echo 'var dataArray = [';

while($row <= $number_of_rows) {

echo '["",'.
$data_array['low'][$row-1]
.','.
$data_array['open'][$row-1]
.','.
$data_array['close'][$row-1]
.','.
$data_array['high'][$row-1]
.'],
';

$row = $row + 1;

}

echo '];';
?>

January 10, 2012

Idea Overload update

0 comments
A new version of Idea Overload is online:

  • New business ideas
  • Slightly improved layout
  • New quotes

Go and check it out at: Idea Overload - Find new ideas

January 8, 2012

Create a Startup with enough resources - and not more

0 comments
More money, more time, more experience, or better contacts are all variables that would help in realizing an intersectional idea, we imagine. They do help, obviously, but not necessarily by decreasing the risk of failure. These resources are all factors that can help us in what we can accomplish, but they do not increase the chances of it succeeding, since with more resources we will try to accomplish more.
More money leads to greater spending. Having greater experience or better contacts means relying more on them to get things done.

What you need is the minimum amount of resources - there's no point in waiting!

Source: The Medici Effect 

January 6, 2012

Quote: Larry Page vs Venture Capitalist

0 comments
Venture Capitalist: "80 percent of all startups fail"

Larry Page (co-founder of Google): "Yes, but most of them are restaurants"

Source: The book Google-koden (Swedish)