Could someone explain these Thinkscript statements?

[cay7man]

1. def peak = high > Highest(high[1], LeftBarsThreshold) and high >= Highest(high[-RightBarsThreshold], RightBarsThreshold);
plot peakBoolean = peak;

Assuming LeftBarsThreshold is 5, Highest(high[1], LeftBarsThreshold) is Highest of 5 bars from 1 bar ago?
Assuming RightBarsThreshold is 5, Highest(high[-RightBarsThreshold], RightBarsThreshold) is Highest of 5 bars from 5 bars ago? I'm bit confused with the use of negative sign in front of bar index. Why not use Highest(high[5],RightBarsThreshold)?

2. def peakValue = if peak then high else peakValue[1];

What will be the value of peakValue[1] when the the above statement was executed for the first time? Does the array (peakValue) grow as each bar
is processed?

TY!

 

[halcyonguy]

1. def peak = high > Highest(high[1], LeftBarsThreshold) and high >= Highest(high[-RightBarsThreshold], RightBarsThreshold);
plot peakBoolean = peak;

Assuming LeftBarsThreshold is 5, Highest(high[1], LeftBarsThreshold) is Highest of 5 bars from 1 bar ago?
Assuming RightBarsThreshold is 5, Highest(high[-RightBarsThreshold], RightBarsThreshold) is Highest of 5 bars from 5 bars ago? I'm bit confused with the use of negative sign in front of bar index. Why not use Highest(high[5],RightBarsThreshold)?

2. def peakValue = if peak then high else peakValue[1];

What will be the value of peakValue[1] when the the above statement was executed for the first time? Does the array (peakValue) grow as each bar
is processed?

TY!

Assuming LeftBarsThreshold is 5, Highest(high[1], LeftBarsThreshold) is Highest of 5 bars from 1 bar ago?
yes

Assuming RightBarsThreshold is 5, Highest(high[-RightBarsThreshold], RightBarsThreshold) is Highest of 5 bars from 5 bars ago?
no

a negative offset, means look at future bars. this means,
high[-RightBarsThreshold]
move to the right 5 bars.

Highest( high[-5] , 5 )
this means, Find the highest value for high over 5 bars.
The -5 offset on high, means to change the starting bar for highest(). to move 5 bars to the future , the right.
then look left and find the highest of 5 bars.

this range won't include the current bar.
high[1] , means to move 1 bar left.
highest( high, 1) , means to find the highest value over a range of 1 bar, just the current bar.


https://tlc.thinkorswim.com/center/...dvanced/Chapter-12---Past-Offset-and-Prefetch

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2. def peakValue = if peak then high else peakValue[1];


What will be the value of peakValue[1] when the the above statement was executed for the first time?
0 or na

Does the array (peakValue) grow as each bar is processed?
no

when peak is true, peakvalue will be = to the high.
when peak is false, peakValue will be set with a value from The 2nd half of the if then statement, peakValue[1] , which is the value of the previous bar.
So when a peak happens, the high is read. then that value is saved in future bars, until a new peak is found.

If this is plotted it will be several horizontal lines, extending from peaks.
plot z = peakValue;