Quote from spreadbet:
Hi all
Can anyone tell me where to find an in depth description of PSR, I know how to use it but I am trying to find the mathematical calculation and perhaps any explanation of the mathematical model.
Stay Lucky
spreadbet
i have simular question-trying to code it in VB-how to start?
tradesttion help and others assume that you on first bar of calculation in some position-either shor or long and goes from there. but how to start if you not on market at all? rest of it is simple, but for me-calculation first parabolic point is a problem. i was trying to figure out how SAR for second bar in Tradestation chart been calculated and still have no idea.
hope someone can help me too
here is explanation for first guy from omega-
The concept draws on the idea that time is an enemy, and unless a trade can continue to generate more profits over time it should be liquidated. Thus, the Parabolic Time/Price Strategy rides the trend until the SAR (stop and reversal) price is penetrated. Then the existing position is closed out and the reverse position is opened.
The expression âparabolicâ derives from the shape of the curve the stops create as the onscreen trading cues appear on the chart.
To calculate the function, we must first find an extreme reference point. On the long side this price is usually the lowest price recorded during the previous closed short position. On the short side this extreme price is usually the highest price recorded during the previous closed out long position.
In practice, however, you wonât have an extreme reference point for the very first trade as there are no previous trades. To account for this, the function uses the High or Low of the previous bar (depending on whether the position is long or short) before the first trade.
For long-side sells and short-side buy, on the second day and thereafter, the SAR is adjusted as follows:
SARb = SARp +AF(H-SARp)
SARs = SARp +AF(L-SARp)
â¦where
SARb is the long-side sell stop price at which you sell to exit the long position and establish a short position.
SARs is the short-side buy stop at which you buy to close the short position and establish a long position.
SARp is the previous barâs SAR
AF is an acceleration factor that begins at .02 for the bar after the initial SAR buy stop order opens the long trade and is increased by .02 each period that price rises to the highest level (H) since the current long trade was opened. For periods when price does not set a new High within the current long trade time duration, AF is left unchanged from its previous periodâs level.
H is a new highest price since the current long trade was opened on a stop buy order.
L is a new lowest price since the current short trade was opened on a stop sell order.
The value returned by the Parabolic function is the SAR value described above.
Reference
Wilder, Welles, Jr. New Concepts in Technical Trading Systems. Trend Research. McLeansville, NC
hope it helps...