Printing service json - chart size proportion

[LuQuan182]

Hi Everybody,

I'm trying to build the json body for the printing service,

i've done the work of reverse engineering of the service, 

and now i have a doubt about the  size proportion of the chart,

i saw on the cliend-side that is dynamically calculated from the webpage,

the question is how can i manage the size proportion of the image chart on the server-size for the printing service?

Thank you,

Lu Quan