rxjs5 - RxJS: Chained Observables Not Using the Same Root Observable Values -

i'm trying learn rxjs , attempting build thought simple , straightforward example. create observable of random numbers generated on interval, use 2 other observables based on observable track lowest , highest values had been seen.

the rngstream seems behave expected, minstream , maxstream both appear track correctly well. problem i'm having when executes seems rngstream, minstream, , maxstream have different random numbers on each interval. i'm trying understand if that's expected or if i've set incorrectly.

my goal output like:

[27, 27, 27] [13, 13, 27] [90, 13, 90] [42, 13, 90] ... 

let rngstream = rx.observable    .interval(1000)    .map(() => math.ceil(math.random()*100))    .take(5);    // track lowest number we've seen.  let minstream = rngstream    .startwith(100)    .scan((x, y) => math.min(x, y))    // track highest number we've seen.  let maxstream = rngstream    .startwith(0)    .scan((x, y) => math.max(x, y))    rx.observable.zip(rngstream, minstream, maxstream)    .subscribe(console.log);

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https://www.youtube.com/watch?v=3lkmwkuk0ze

this video clarified lot of things me. @ 32:00 mark mentions .share makes observable multicast. default every subscriber own copy. fix looks this:

let rngstream = rx.observable    .interval(1000)    .map(() => math.ceil(math.random()*100))    .take(5)    .share();    // track lowest number we've seen.  let minstream = rngstream    .startwith(100)    .scan((x, y) => math.min(x, y))    // track highest number we've seen.  let maxstream = rngstream    .startwith(0)    .scan((x, y) => math.max(x, y))    rx.observable.zip(rngstream, minstream, maxstream)    .subscribe(console.log);

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