How to make linechart with picasso.js and picasso-plugin-q?

[Nost]

For example, I tried to make base Line chart from Qlik sense, here is my data: 

So i pick two dimensions - a and b, and pick measure sum(c)

That's how basic Qlik sense line chart looks like: 

And that's how is my line chart looking: 

I use code from here. Please help me to understand, what did I do wrong