Help with loop

[kingmins]

Hi, i have been trying to understand loops and trying to get the efs to draw a line from the highest high in 'n' number of bars looking backwards. This works but for some reason it is also drawing a line underneath almost like it should be on a 'non price study'.

Anyway here is my script and also i have shown image or the error:

function preMain(){
setPriceStudy(true);
setShowCursorLabel(false);
}

function main() {

var Source = high(); // these are used as parameters for study
var Length = 100; // this is bars to look backwards

var vValue = Source.getValue(0);
var barIndex = 0;
for(var i = 0; i < Length; i++) {
vValue = Math.max(vValue, Source.getValue(-i));
if(vValue == Source.getValue(-i)){
barIndex = getCurrentBarIndex()-i;
drawLineRelative(barIndex, high(barIndex), 0, high(barIndex), PS_SOLID, 1, Color.red, "line1");

}
}
return barIndex;
}

[kingmins]

Referring to Values in a loop

Okay i have figured out how to use loops. However, i am having difficulty in accessing values within the loop i created e.g.

 var Source2 = high();
 var vValue2   = Source2.getValue(15);


for (h = -15; h < 0; h++)       {  
     vValue2 = Math.max(vValue2, Source2.getValue(-h)); 
   
 if (vValue2 == Source2.getValue(-h))        { 
        barIndex2 = getCurrentBarIndex()-h; 
       }
}

Now lets assume this is all fine and it returns me the values (in this case the Highest high looking forward 15 bars from entry point). However, i now wish to make conditions for the loop to process (all for backtesting purposes) such as:

- I want to return (vValue2 +1) e.g. 'vValue2' has been returned as the highest high (15 bars) and now i want to know the value of 'vValue2 +1 bar' even if this is not the highest bar.
- Is there a way for the loop only to return values if multiple conditions are met such as:
i. Return the first Highest high of the 15 bars (lets say 'h') IF the bar ('h' +1) of this return value has a LOW which is less than the LOW of ('h') && ('h'+2), ('h'+3), ('h'+4), all have High less than ('h').

Basically i want to add multiple IF conditions to start a loop?? Or am i supposed to add the IF conditions after a loop has returned its values???

- I am not sure if the things i require are possible or must i use loop after loop to get the desired results.

[waynecd]

This works but for some reason it is also drawing a line underneath almost like it should be on a 'non price study'.

The blue line at the bottom of your chart is the "return barIndex;" returned as a plot on the chart. The barIndex plot scale takes precedence over the price plot and since the barIndex values are negative and much less than the price values the price scale is squeezed into a small range.

If you just want to see the values of "barIndex" in the cursor window without plotting them just replace the

return barIndex; 

to

return barIndex+""; 

[waynecd]

Strictly using your code and approach:

 var Source2 = high();
 var vValue2   = Source2.getValue(15); 

Here .getValue(15) is looking at fifteen bars in the future.
Change it to:

 var Source2 = high();
 var vValue2   = Source2.getValue(-15);
 var vValue3 = Source2.getValue(-14); 

Now vValue2 has the high of the bar 15 bars back from bar 0 (current bar is bar 0) and vValue3 has the high of the next bar (14 bars back).

Maybe a better approach would be something like the following:

//I recommend you study eSignal functions found at:
//http://kb.esignal.com/display/2/index.aspx?c=12&cpc=ULwO0A442oKs512Q04X5j0UupP4SveI6dt2WJi7&cid=4&cat=&catURL=&r=0.856125354766846
debugClear();
function preMain(){
    setPriceStudy(true);
}
var barIndex2,vIdx3;
function main(){
    var vHHV;
    vHHV=hhv(15, high()); //returns the highest high for the last 15 bars
    for (h = -15; h <= 0; h++)       {  
        //Note: There could be more than one bar with a high of vHHV.  The loop will return values for the last bar with a high = vHHV
        if (high(h) == vHHV){ //to see if the bar(-h) equals the highest high to get it's index
            barIndex2 = h; //index of the last bar with a high equal to the highest high of the last 15 bars
            vIdx3=h+1; //this is the index of the bar after the bar with high = vHHV
        }
    }
    //now "barIndex2" contains the bar index for the last bar with a high equal to the highest high value over the last 15 bars
    //"vIdx3" contains the bar index for the bar after "barIndex2"
    return new Array(high(0),barIndex2+"",vIdx3+"",vHHV+"");
}