Line/b-spline charts with movable data points and integral/area calculation (jQuery)

I'm looking for some sort of jQuery plug-in that will create charts where I can drag the data points. B-splines and area/integral calculation features would be nice, but if that is impossible, then no biggie.

HighCharts: looks amazing and supports b-splines, though I'm not sure it has area/integral calculation functionality. Unfortunately, they have no demo where the data points are movable, so I'm rather worried that I'll have to end up programming this myself. It also costs $80-360 depending on the lic开发者_高级运维ense, and I'd prefer to avoid spending money if I can... especially if I'm not going to get movable data points.

jQPlot: Movable data points, but whether or not it can be made to avoid multivalued functions (e.g. two y values for one x value -- a zigzag) is unknown to me. Most likely does not have area/integral calculation functionality, but seeing as how it doesn't have b-splines, that would be extremely easy to add.

Flot: Looks ok, but there is no demo of movable data points. Unless I'm missing something, Flot seems like it isn't what I'm looking for.

My question is basically this: Is there a jQuery plug-in that would do what I need without much work? Am I missing one, or am I wrong about the functionality of some of the above plug-ins -- for example, does HighCharts have movable data points?

You can download HighCharts and work with it for a while without having to pay for it. If you decide that it is what you need, then you can purchase a license. I'm doing the same thing for a report engine I am building.

I have written a library for doing the same. It is currently in a very basic shape but you can expect it to improve over time. Also it is in lean shape so you can make modifications of your own.

https://github.com/akshar100/Rapheal-Drag-Chart