Timeseries data consistency

[CrashLaker]

How to cope when shrinking a timeseries dataset?

I noticed that:
x = Array.apply(null, Array(y.length)).map(function (_, i) {return i;}) in index.html only gives us the indexes related to y`s length

I tried doing something like this but I doubt its correctness..

smooth_val = 100
var y = smooth(rsdata["values"], smooth_val)
step - Math.ceil(rsdata["timestamps"].length/smooth_val)
x = rsdata["timestamps"].filter((x,i) => i%step == 0)

does anyone have a solution?