BUG or NOT ??? is support read posts?

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cmon support, how bout some SUPPORT ???

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PLEASE notice how MY HACK works correctly and MathMod() still results in wrong answers.

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OR does this highlight a bug in the interpreter/compiler/watevr u using...?

why? is the if condition that is giving issue ??

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i have demonstrate below and also on another thread

how about some answers???

i not mind i mistaken - but cmon, GIVE SOME SUPPORT, ok?

if i all wrong ok, put me right but let's get this sorted

thankyou

.

#property show_inputs
extern double dVolume=0.1;
int start()
{
double dLotStep=0.01;

  Print("<1> MathMod(",DoubleToStr(dVolume,8),",",DoubleToStr(MarketInfo(Symbol(),MODE_LOTSTEP),8),")=",MathMod(dVolume,MarketInfo(Symbol(),MODE_LOTSTEP)));
  if(MathMod(dVolume,MarketInfo(Symbol(),MODE_LOTSTEP))!=0)
    Print("<1> dVolume incorrect");
  else Print("<1> dVolume correct");
  
  Print("<2> MathMod(",DoubleToStr(dVolume,8),",",DoubleToStr(dLotStep,8),")=",MathMod(dVolume,dLotStep));
  if(MathMod(dVolume,dLotStep)!=0) {
    Print("<2> dVolume incorrect");
  }
  else Print("<2> dVolume correct");
  
  Print("<3> dVolume - dLotStep * MathFloor(dVolume/dLotStep) = "
        ,DoubleToStr(dVolume,8)," - ",DoubleToStr(dLotStep,8)," * MathFloor(",DoubleToStr(dVolume,8),"/",DoubleToStr(dLotStep,8)
        ,") = ",dVolume - dLotStep * MathFloor(dVolume/dLotStep));
  if(dVolume - dLotStep * MathFloor(dVolume/dLotStep)!=0) {
    Print("<3> dVolume incorrect");
  }
  else Print("<3> dVolume correct");
  
  return(0);
}

/*
<3> dVolume correct
<3> dVolume - dLotStep * MathFloor(dVolume/dLotStep) = 0.05000000 - 0.01000000 * MathFloor(0.05000000/0.01000000) = 0
<2> dVolume incorrect
<2> MathMod(0.05000000,0.01000000)=0
<1> dVolume incorrect
<1> MathMod(0.05000000,0.01000000)=0
inputs: dVolume=0.05;

<3> dVolume correct
<3> dVolume - dLotStep * MathFloor(dVolume/dLotStep) = 0.01000000 - 0.01000000 * MathFloor(0.01000000/0.01000000) = 0
<2> dVolume correct
<2> MathMod(0.01000000,0.01000000)=0
<1> dVolume correct
<1> MathMod(0.01000000,0.01000000)=0
inputs: dVolume=0.01;

<3> dVolume incorrect
<3> dVolume - dLotStep * MathFloor(dVolume/dLotStep) = 0.12300000 - 0.01000000 * MathFloor(0.12300000/0.01000000) = 0.003
<2> dVolume incorrect
<2> MathMod(0.12300000,0.01000000)=0.003
<1> dVolume incorrect
<1> MathMod(0.12300000,0.01000000)=0.003
inputs: dVolume=0.123;

<3> dVolume correct
<3> dVolume - dLotStep * MathFloor(dVolume/dLotStep) = 0.10000000 - 0.01000000 * MathFloor(0.10000000/0.01000000) = 0
<2> dVolume incorrect
<2> MathMod(0.10000000,0.01000000)=0
<1> dVolume incorrect
<1> MathMod(0.10000000,0.01000000)=0
inputs: dVolume=0.1;
*/
 

i then put brackets around my HACK to highlight wat would expect operator precedence to be doing anyways and get strange result?

wat up with if condition evaluation code in MQL4 ?

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<5> dVolume incorrect BUT is not * higher precedence than - ? meaning using "(..)" should not make any differecne to outcome of expresion

and so it appears below BUT wat is if condition evaluation code doing????

ZERO is FALSE, yes? so why if seeing TRUE ie, !=0 ??

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<5> dVolume incorrect
 <5> dVolume - (dLotStep * MathFloor(dVolume/dLotStep)) = 0.10000000 - (0.01000000 * MathFloor(0.10000000/0.01000000)) = 0
<3> dVolume correct
<3> dVolume - dLotStep * MathFloor(dVolume/dLotStep) = 0.10000000 - 0.01000000 * MathFloor(0.10000000/0.01000000) = 0
<2> dVolume incorrect
<2> MathMod(0.10000000,0.01000000)=0
<1> dVolume incorrect
<1> MathMod(0.10000000,0.01000000)=0
inputs: dVolume=0.1;

 

Perhaps you are bumping into "known problems" with the imprecision of binary representations of floating point numbers...

http://www.h-schmidt.net/FloatApplet/IEEE754.html

 

please explain in simple terms. thankyou. i not 'get' wat u on about or how relate to simple demonstrated inconsistency in how expression evaluates to ZERO in one statement but decides NOT ZERO in if condition expresion evaluation - that not consistent is it?

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i and code/print see ZERO and if condition sees non ZERO

sorry, but not see how this relate to imprecision of anything but interpreter.

if this is known problem then why no response from support?

i not get any of this.

1. print ok

2. if evaluation not ok

so wat to do with known problems or imprecision?

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ok... maybe best i do own Mod(a,b) = a-b*floor(a/b)

but this not issue is it?

all revolves around the if condition - stuff inside (...) is expresion. stuff on own in statement is expresion - wat diff? both expresions... not get it.

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as u see, ZERO is printed

then magically, if condition not see ZERO

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again, not see how anything do with your comment

thank you for help? but this go nowheres fast i think

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strange on support? silence - they gurus, i only asking for 'ultimate' ruling and solution/workaround/watevr, not care - just want genrl fix so all code work ok.

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is this to much ask???

 

Once more

https://docs.mql4.com/common/Print

"Data of double type are printed with 4 decimal digits after point. To output more precisely, use the DoubleToStr() function."

You can use our DoubleToStrMorePrecision from our stdlib. Also see as example CompareDoubles function in our stdlib.

"strange on support"... try to find "compare doubles" - this subject is discussed every month.

 

"if this is known problem then why no response from support"

(1) This is known problem of Computer Science, not MQL.

(2) Moderators have stated in the past this is "Community Forum" not specifically "Product Support Forum"

I suggest you convert your values to integers for comparison in this case.

 

ok, dblmoreprecision, computer science, community forum - both ur times - thanks

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