Comparing Values Against a Range

[underdog430]

What is the best way to compare values against a range? Note that I don't yet have a good grasp of arrays or ref.

example 1: NR7

How can I determine if a bar has the lowest range of the past 7 bars?

example 2: Inside Day Variation

How can I determine if a bar (the range contained within the high and the low) contains (has a higher high and a lower low than) the next x bars that follow?

Thanks for any assistance.

Mark

[eSignal_JasonK]

Hello underdog430,

To learn more about arrays, click here. To learn more about ref(), click here.

If I interpreted your post correctly, the code below will show you how to get your results.

function preMain() {
    setPriceStudy(true);
}

function main() {
    var nLength = 7;
    var curHigh = high()
    var curLow = low()
    if (curHigh == null || curLow == null)
        return;

    
    //  1. Determines if current bar's range is the lowest of last nLength bars.
    var pastHighs = high(0, -nLength);
    if (pastHighs == null)
        return;
    var pastLows = low(0, -nLength);
    if (pastLows == null)
        return;
        
    var curRange = (curHigh - curLow);
    
    var isLowest = true;
    for (i = 0; i < nLength; ++i) {
        if ((pastHighs[i] - pastLows[i]) < curRange) {
            isLowest = false;
            i = nLength
        }
    }
    if (isLowest == true) {
        // Open the formula output window to view these results.
        debugPrintln("Bar index " + getCurrentBarIndex() + " has a lower range than the last " + nLength + " bars.");
    }

    //  2.  Determines if current bar's range has a higher high and lower low than the next nLength bars.
    //      Note:  This can only return valid results on historical data as the formula iterates through 
    //      your chart from the oldest bar to the newest.
    var futureHighs = high(0, nLength);
    if (futureHighs == null)
        return;
    var futureLows = low(0, nLength);
    if (futureLows == null)
        return;
    
    var HH = true;
    var LL = true;
    for (i = 0; i < nLength; ++i) {
        if (futureHighs[i] > curHigh) {
            HH = false;
            i = nLength;
        }
        if (futureLows[i] < curLow) {
            LL = false;
            i = nLength;
        }
    }
    if (HH == true && LL == true) {
        // Open the formula output window to view these results.
        debugPrintln("Bar index " + getCurrentBarIndex() + " has a higher high and lower low than the next " + nLength + " bars.");
    }
    
    return;
} 

[Doji3333]

Help - if needed...

Mark,

I've coded systems that look for similar types of things (pivot points). The code is similar to what Jason has shown you. I have posted an example for you to review. Changing the "if" conditions will allow you to ID your conditions.

        var i;
        var nLastLSB = 0;
        var nLastHSB = 0;
        var nLSBSet = 0;
        var nHSBSet = 0;

        for(i = 0; i >= -15; i--) {
          if ( ((nHSBSet == 0) && (high(i) < high(i-1)) && (high(i-2) < high(i-1))) || ((nHSBSet == 0) && (high(i) == high(i-1)) && (high(i-2) < high(i-1)) ) ) {
              nLastHSB = high(i-1);
              nHSBSet = 1;
          }
          if ( ((nLSBSet == 0) && (low(i) > low(i-1)) && (low(i-2) > low(i-1))) || ((nLSBSet == 0) && (low(i) == low(i-1)) && (low(i-2) > low(i-1)) ) ) {
              nLastLSB = low(i-1);
              nLSBSet = 1;
          }
        } // END OF FOR LOOP 

This code looks back 15 bars for a defined pivot point and will return the last occurance of both a HIGH and LOW pivit point.

To convert the code to look for the lowest price range for 15 bars, it might look like this....

         // look for lowest range over 15 bars
        var i;
        var nlastrange = 999999.99;
        var nLastsmallrangebar = 0;

        for(i = 0; i >= -15; i--) {
          if ( ((high(i-1)-low(i-1)) < (high(i)-low(i))) && ((high(i-1)-low(i-1)) < nlastrange)  ) {
              nLastsmallrangebar = i;
              nlastrange = (high(i-1)-low(i-1));
          }
        } // END OF FOR LOOP 

This code will return the bar that has the smallest range and the size of that range.

Hope this helps..

Brad

[underdog430]

Thanks for your comments. I think I need more help with "for". I can kind of see how it creates a loop checking old values but I'm still not clear on what it does then. For example, how would you set it to check the last 5 highs and make the highest one the vPivot?

Once I get a better understanding I'm interested in the Rectangle Trading System (Acme R) from Conway and Behle's "Professional Stock Trading". Conway has encouraged people to post the code for his systems on the TradeStation boards (it is provided in the book) so I would be surprised if he objected.

Basically, if the range from the last 4 bars divided by the range for the 12 bars before that <= 0.3 and the range for the last 4 bars <= 30 period ATR, then you buy the next bar at or above the 4 bar high (plus an amount you decide on) or sell the next bar at or below the 4 bar low (minus an amount you decide on). Exits are based on profit targets and stop losses.

[eSignal_JasonK]

Hello Mark,

Here is an example of the for loop you need for finding vPivot. It will look at the five bars prior to the current bar. If you want to look at the five most recent bars including the current bar, change 1 and 6 to 0 and 5.

var vPivot = 0;
for(i = 1; i < 6; ++i) {
     vPivot = Math.max(vPivot, high(-i));
} 

The way to read this for loop goes something like this:
"(i = 1;"
i will start at 1.

"i < 6;"
If i is less than 6 (returns true/false), compute the code in the loop.

"++i)"
Then increment i by +1 and check the true/false condition for the loop again.

Once i = 6 the loop ends. Hope this helps.

[underdog430]

OK, I'm trying to find the highest high and the lowest low for the past nRectangle number of bars on a moving basis. The problem with the code below is that it doesn't really operate on a moving basis (it doesn't limit itself to the past nRectangle number of bars). For example, if the low of the day is set at 9:30 and the bar lows rise steadily after that, vRectangleL doesn't rise with them. Do I need to modify the code or take a new approach?

Thanks.

// Highest High and Lowest Low for Rectangle

for(i=1; i < nRectangle; ++i) {
    vRectangleH = Math.max(vRectangleH, high(-i));
    vRectangleL = Math.min(vRectangleL, low(-i));
} 

[Doji3333]

High and Low range...

Underdog,

O don't really understand you statement, but lets say that a low was set at 9:30, what is it that you want to try to accomplish?? Are you trying to identify the lowest low and highest high of n bars?? If so, then you would want to set the initial values to extreme levels to start with...like...

// Highest High and Lowest Low for Rectangle
vRectangleH = -99999;
vRectangleL = 99999;

for(i=1; i < nRectangle; ++i) {
    vRectangleH = Math.max(vRectangleH, high(-i));
    vRectangleL = Math.min(vRectangleL, low(-i));
} 

This code should return the highest high and lowest low of nRectangle bars.

Lets say you wanted to fing the highest high and lowest low of n bars from where a pattern was found. Then you would have to record the bar number and count the number of new bars after the pattern was formed to determine how far back to set nRectangle. Use my "time-stamping" functions for this as a solution.

If you can describe what you are trying to accomplish in detail, then I will be able to provide more detailed assistance...

Brad

[Doji3333]

Rectangle...

Underdog,

The rectangle is not reactive to the change in variable price.

After you identify the new high and low, you would need to redraw the rectangle. This would cause the rectangle to redraw with the new prive variables. You would have to force the change in the rectangle size by re-issuing the DRAW functions to draw the rectangle.

I hopd this is clear.

To simplify things.... just changing the variable values will not cause the rectangle to redraw with the new shapes. The graphics have to be redrawn with the new values.

Brad

[rhbishop]

Hi Underdog. If I understand you correctly, what you need to do after each bar is completed is to reinitialize your high and low variables to the open of the bar under construction.

Good Luck, Bob

[rhbishop]

OOPS, meant to say reinitialize to the open of the first bar of the rectangle.

[underdog430]

OK, just got to reinitialize the variables. I've been tripped up by that kind of thing before. Thanks all.

Mark