bug?

[clearpicks]

I encountered a very strange error while debuging my EFS. I wrote the attached simplified EFS to reproduce the error. If you apply this EFS to an advanced chart showing ($TICK,T) with time template 8:30-16:00. In some cases, when tick is larger than tick1, the result of "tick > (tick1 + 0.5)" is false. For example, in the output window, near the line "t = 3363 ......", tick = -31, tick1 = -49, but the program considers the tick is smaller than tick1. Similar cases appear at other lines. It seems this error most likely occurs when tick accrosses 0 and it appears quite randomly. Help is greatly appreciated.





/* Reproduce the Bug */
var tick, tick1, t;

function preMain() {
setStudyMin(0);
setStudyMax(280);

setDefaultBarFgColor(Color.blue, 0);
setDefaultBarFgColor(Color.red, 1);

setStudyTitle("Test");
t = 0;
}

function main() {



if ( getBarState() == BARSTATE_NEWBAR ) {

var ticktmp = tick;
tick1 = ticktmp;
tick = getValue("Close", 0, 1, "$TICK,T");
//t = getValue("Time", 0, 1, "$TICK.T");
t = t + 1;

var W;
W = Math.round(tick);

if ( tick > (tick1 + 0.5) ) {
debugPrintln("t = " + t + " Tick = " + tick + " Tick1 = " + tick1 + " up");
}
else {
debugPrintln("t = " + t + " Tick = " + tick + " Tick1 = " + tick1 + " down");
}
}
}

[clearpicks]

if I replace "if ( tick > (tick1 + 0.5) ) {" with "if ( Math.abs(tick-tick1) == (tick - tick1) ) {", I will get the correct answer. Therefore I believe there is some serious problem here. Can somebody run this script to verify this is a real problem? If it is run tomorrow, the resault will be different so that you have to find the line where the error is.

[clearpicks]

Still no reply?
If you run the script I attached on today's ($TICK,T) chart, you will find "t = 2072 Tick = -28 Tick1 = -38 down" in the printed results. I havn't find out the reason yet. Can eSignal technical support guys run the script once and look into it? Thanks.

[JayF]

clearpicks,

I am able to duplicate this problem. It seems related to using getValue() with $TICK,T. If I run the below on a $TICK,T chart the output is fine.

/* Reproduce the Bug */
var tick, tick1, t;

function preMain() {
    setStudyMin(0);
    setStudyMax(280);
    
    setDefaultBarFgColor(Color.blue, 0); 
    setDefaultBarFgColor(Color.red, 1); 
    
    setStudyTitle("Test");
    t = 0;
}

function main() {
    
    if ( getBarState() == BARSTATE_NEWBAR ) { 
    
        var ticktmp = tick;
        tick1 = ticktmp;
        tick = getValue("Close"/*, 0, 1, "$TICK,T"*/);
        t = t + 1;
        
        var W;
        W = Math.round(tick);
        
        if ( tick > (tick1 + 0.5) ) {
            debugPrintln("t = " + t + " Tick = " + tick + " Tick1 = " + tick1 + " up");
        } else {
            debugPrintln("t = " + t + " Tick = " + tick + " Tick1 = " + tick1 + " down");
        } 
    } 
} 

[clearpicks]

Thanks for the reply. However if you look at my script and the output in the debug window, you will find the printed tick and tick1 values are correct, but the comparison result is wrong. In any circumstance, (-28) SHOULD be larger than (-38), isn't it? Any explaination on this? I had similar problems several monthes ago ( it was not comparison of tick values ). Because I didn't continue to work on that indicator, I didn't look at this problem seriously until now. If it is really caused by the comparison part, I have to worry more about the credibility and correctness of EFS language.

[eSignal_JasonK]

Hello clearpicks,

I've verified this problem as well. The only instance that I've seen where the comparison failed was when t = 4. I'm not sure if this is a problem with the getValue() function or within the engine, but I will forward this info to our senior developers.

When using getValue() to return a single value, EFS returns a string, so you have two options to solve the problem. Multiply your getValue() result by 1 or use the close() function. Try the following.

/* Reproduce the Bug */
var tick, tick1, t;

function preMain() {
setStudyMin(0);
setStudyMax(280);
setDefaultBarFgColor(Color.blue, 0); 
setDefaultBarFgColor(Color.red, 1); 
setStudyTitle("Test");
t = 0;
}

function main() {
    if ( getBarState() == BARSTATE_NEWBAR ) { 
        var ticktmp = tick;
        tick1 = ticktmp;
        tick = getValue("Close", 0, 1, "$TICK,T")*1;
        if (tick == null) return;
        // or use 
        //tick = close();
        t = t + 1;
        var W;
        W = Math.round(tick);
        if ( tick > (tick1 + 0.5) ) {
            debugPrintln("t = " + t + " Tick = " + tick + " Tick1 = " + tick1 + " up");
        } else {
            debugPrintln("t = " + t + " Tick = " + tick + " Tick1 = " + tick1 + " down");
        } 
    } 
    return;
} 

[gspiker]

I think Jay is correct. If you run the below EFS the way it is all results will be correct on a $TICK,T chart (this is the same thing Jay did). If you uncomment out the tick = close(); and the take out the comments in front of the original tick = statement the error will show itself again.

If you try the exact same thing but use IBM,15 say for the formula and the chart it works fine.

There is some bug with the way that $TICK,T is returning data in the statement.

Garth

/* Reproduce the Bug */
var tick = 0;
var tick1 = 0;
var t = 0;

function preMain() {
// setStudyMin(0);
// setStudyMax(280);

setDefaultBarFgColor(Color.blue, 0); 
setDefaultBarFgColor(Color.red, 1); 

setStudyTitle("Test");
}

function main() {

    if ( getBarState() == BARSTATE_ALLBARS )
        t = 0;

    if ( getBarState() == BARSTATE_NEWBAR ) { 

        tick1 = tick;
        tick = getValue("Close");
        // tick  = getValue("Close", 0, 1, "$TICK,T");
        //t = getValue("Time", 0, 1, "$TICK.T"); 
        t = t + 1;
        
        if (isNaN(tick) || isNaN(tick1)){
            debugPrintln("*********NAN*********");
        }

        if ( tick > tick1 ) {
            debugPrintln("t = " + t + " Tick = " + tick + " Tick1 = " + tick1 + " up");
        } 
        else {
            debugPrintln("t = " + t + " Tick = " + tick + " Tick1 = " + tick1 + " down");
        } 
     } 
} 

[gspiker]

When using getValue() to return a single value, EFS returns a string, so you have two options to solve the problem. Multiply your getValue() result by 1 or use the close() function. Try the following.

To convert a string to an Int, I would use parseInt() instead of multiplying by 1.


Also, I'm not sure getValue() returns a string, in fact I think it returns an array if the return is greater than one. However in this specific case I can tell you that a string is NOT being returned as I thought that might be the problem and added a check for isNaN(). It never shows that a number is not returned.

Garth