Any good open source API for C#/C++ for plotting timeseries?

Hi there,

 

I'm developing a software that I'd like to augment with a feature allowing the user to plot various time series, ideally incl. filters, zoom in/out, bar charts, line charts, ...

 

Any ideas of open source software/APIs that could be useful?

 

My program is written in C#.

 

Thank you,

Martin