Sunday, February 24, 2008

Google Chart API--why it's not important in BI?

Just for curiosity I took a look at Google Chart API. Here are two sample charts I created with it.







Nice charts. As the data and axes are controlled separately, it's possible to compose:

  • A chart where axis labels are qualitative--not quantitative--which is sometimes a preferred situation in an XY chart (good vs. poor etc)
  • A line chart where the line changes it's value several times within a month--not easily done in Excel or other BI tools having a direct correspondence between data values and categories displayed in the X axis
As a BI consultant, should I be interested in Google Charts?

- No. Google Chart API is a programmer tool to build larger systems.

OK. When such a larger system appears, should I be interested then?

- No again. All Google Charts are by nature static pictures (PNG files), without any means to add user interaction.

For example, if you move the mouse cursor onto a symbol (or click the symbol) in the XY chart above (or onto the line chart), nothing happens. Simply said there's no mechanism to display what the symbols represent (or what is the exact value displayed in the line chart). It's not possible to program drilling-down either. And all these features are essential in business intelligence...

Anyway, I had fun going through the Google Chart API. If you have a mind of a programmer, it's worth studying. Here are the urls which I used to create the XY chart and the line chart (broken into several lines for clarity).
  • XY:
    http: //chart.apis.google.com/chart?cht=s
    &chd=s:984sttvuvkQIBLKNCAIi,DEJPgq0uov17zwopQODS,AFLPTXaflptx159gsDrn
    &chxt=x,y
    &chtt=Google+Chart+API+-+Sample+XY
    &chxl=0:Good|Poor1:Small|Large
    &chs=250x250
    &chm=o,ff000033,1,1,25
    &chg=50,50,2,5
  • Line:
    http: //chart.apis.google.com/chart?cht=lc
    &chd=s:rpnpnosztwurrmmllgbZQOOORVURRSQROQSRSTKCBIKIKMLIIJIKLJKKNLNVWakiljhfedcbdcZbbZ, UVVUVVUUUVVUSSVVVXXYadfhjlmpokllmmliigdbbZZXVVUUUTU
    &chco=5555ff,ff9933
    &chtt=Google+Chart+API+-+Sample+Line
    &chls=2.0,1.0,0.0
    &chxt=x,x,y
    &chxl=0:||Oct||Nov||Dec||Jan||Feb||Mar||Apr||May||1:||2007||||||2008||||||||||2:60|70|80|90|100
    &chs=320x175
    &chg=101,25,2,5
    &chf=c,ls,0,f4f4ff,0.125,ffffff,0.125
    &chdl=First|Second