Monday, April 19, 2010

Graphing Challenges for Android


Hello Everyone, here I’ll be blogging about using Google Image
Charts in Android phone. Let’s get acquainted with Google Image 
Charts. The Google Chart API lets you dynamically generate 
charts with a URL string. You can embed these charts on your 
WebView or download the image for local or offline use. It
returns a PNG image of a chart in response to a URL GET or
POST request.There are a lot of types of charts and you can
specify its size,colors,labels and other properties. Let’s 
create a simple chart.

1.Decide on a chart type.
  Chart type is specified by the "cht" parameter.

2.Choose a data format and decide whether your data must be
  scaled to fit your chart.
  Data is specified using the "chd" parameter

3.Specify the chart size.
  Chart size is specified using the "chs" parameter.

4.Add additional parameters.
  You can find some of possible parameters below.

  chxr  -  specifies the range of values that appear on 
           each axis independently
  chds  -  specifies parameters to scale the numeric
           value displayed
  chg   -  specifies solid or dotted grid lines
  chco  -  specifies the colors of a specific series
  chf   -  specifies fill colors and styles for the 
           chart data are and/or the whole chart
           background
  chxl  -  specifies string axis labels on any axis
  chm   –  specfies graphical markers for data points
           on a chart

5.Build your URL String.
  The URL start with http://chart.apis.google.com/chart?
  and is followed by all required and optional parameters.

6.Use GET or POST to get image.
  URL-s  are limited to 2k in length, so if you have
  more data you should consider using POST.

No comments:

Post a Comment