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A Java Applet for

Drill Down Charts

Rated by JARS -Java Applet Rating Service

Click Here for the New Version with more views and datafile support

Overview of Drill Down Charts

Drill Down charts are used to present hierarchically ordered information. First you present birds eye view - summarized information showing main highlights. To explore further the user clicks on one of the highlighted feature. You show some details relevant to the highlighed features. The users clicks on one of the details. Up comes more info and so on. It is like surfing. You can navigate down the layers to see more and more details.
In the example chart, sales of Nuts and Nuts Co for the entire country are shown first. The country is divided into four regions and sales for the regions are shown. You can explore a particular region and see the contributions from the subregions. You click a subregion to see the contributions from the cities and so on.
Some people like Pie Charts , some Bar Charts while others are satisfied with a Table of data. You chose the rendering you like.


Sales of Brown Nuts of Nuts & Nuts Co
Click on the pie slice to see what the slice is made off.
Click on a bar to see details of the bar
Click on the table entry to expand the entry

In the example chart, not all the slices have information underneath.
Your browser can not run Java Applet or having problem displaying tables. Drill Down chart is a Java Applet. You will need a Java enabled browser. e.g Netscape 2.1 onwards or InternetExplorer 3.0 onwords


Supplying data to the chart

The <PARAM NAME="..." VALUE="...."> tag is used for specifying data for the chart
NAME identifies the chart and VALUE string supplies data for the chart.
The top chart has special name ie DATASET.
VALUE is a string of triplet of values. (e.g North,25,1)
A triplet consists of a label, a value and a color parameter.
In the example chart we want to display Nuts sold in the regions of the country. The tag is
<PARAM NAME=DATASET VALUE="North,25,1,East,60,2,South,120,3,West,80,4">

The special name DATASET is used to denote the top level chart. It contains four pie slices - namely North, East , South and West. North has value 25 and color code 1 ie blue.
We know the breakup of South value ie 120 which the user can view 'drill down' by clicking on it. We supply another parameter tag for it:
<PARAM NAME=South VALUE="Andhra,25,2,Tamilnadu,50,1,Karnataka,25,3,Kerala,20,4">

The name South should have appeared in the higher level
You can further 'drill down' Tamilnadu by specifying tag for it.

Guidelines for labels

Short labels are convenient to read. Labels should not contain blanks or comma(,). Avoid labels containing blanks. If needed use underscore _ to seperate the words in the label. Label in VALUE of part of tag in higher level chart and NAME tag in the lower chart should be same.
Values suitably scaled improve visual appearance. Units have to be indicated by appropriate coding in HTML script. In this version of charts, the Applet itself does not show units.

Color codes

The third of the triplet specifies color of slice or bar. 1 blue, 2 green and 4 red. Add the values to specify other colors. e.g 6 yellow (green+red) etc

Appearance related parameters
ChartTitle    Title for the chart. Default Drill Down Charts 
<param name=ChartTitle value="Sale of brown nuts(in millions)">
itemwidth    Width in pixels of an item in the bar chart 
             If the parameter is not specified the width is 60			
<param name=itemwidth value=80>
barwidth    Width in pixels of the bars the bar chart
            If the parameter is not specified the width is 8
<param name=barwidth value=20>


About ...
(c)1997 Vasanth Desai

You can download DrillDownChart for trial and evaluation
Click here to download DDC 1.0(27KB)
Click here to download DDC 2.0(23KB)
Note: Extract the contents of the archives in different folders.
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