Chart Type
Specify the chart type using the cht parameter. See the individual chart documentation pages for a list of available chart types.
Syntax
cht=<type>[:nda]
<type>one of the chart type values. Full list of supported values are available in the chart editor.:nda[Optional, line charts only] You can add:ndaafter the chart type in line charts to hide the default axes.
Example
A vertical bar chart
cht=bvs
A pie chart:
cht=p
A line chart without default axes:
cht=ls