THIS INDICATOR, HOW ARE THE BANDS CALCULATED, PLEASE

drlarryvon 2020.12.10 06:40

below is an indicator that plots a band, upper, lower and center bands.

Can anyone with some knowledge explain how the bands are calculated, please.

here is the indie:

#property indicator_chart_window
#property indicator_buffers 5
#property indicator_color1 White
#property indicator_color2 OrangeRed
#property indicator_color3 OrangeRed
#property indicator_color4 White
#property indicator_color5 White
#property indicator_style1 STYLE_SOLID
#property indicator_width1 1
#property indicator_width2 6
#property indicator_width3 6
#property indicator_width4 8
#property indicator_width5 8
//
//
//
//
//

extern string TimeFrame = "current time frame";
extern int HalfLength = 55;
extern int Price = PRICE_WEIGHTED;
extern double BandsDeviations = 2.5;
extern bool Interpolate = true;
extern bool alertsOn = false;
extern bool alertsOnCurrent = false;
extern bool alertsOnHighLow = false;
extern bool alertsMessage = false;
extern bool alertsSound = false;
extern bool alertsEmail = false;

//
//
//
//
//

double tmBuffer[];
double upBuffer[];
double dnBuffer[];
double wuBuffer[];
double wdBuffer[];
double upArrow[];
double dnArrow[];

//
//
//
//
//

string IndicatorFileName;
bool calculatingTma = false;
bool returningBars = false;
int timeFrame;

//+--------------------------- ------------------------------ ---------+
//| |
//+--------------------------- ------------------------------ ---------+
//
//
//
//

int init()
{
timeFrame = stringToTimeFrame(TimeFrame);
HalfLength = MathMax(HalfLength,1);
IndicatorBuffers(7);
SetIndexBuffer(0,tmBuffer); SetIndexDrawBegin(0, HalfLength);
SetIndexBuffer(1,upBuffer); SetIndexDrawBegin(1, HalfLength);
SetIndexBuffer(2,dnBuffer); SetIndexDrawBegin(2, HalfLength);
SetIndexBuffer(3,dnArrow); SetIndexStyle(3,DRAW_ARROW); SetIndexArrow(3,82);
SetIndexBuffer(4,upArrow); SetIndexStyle(4,DRAW_ARROW); SetIndexArrow(4,82);
SetIndexBuffer(5,wuBuffer);
SetIndexBuffer(6,wdBuffer);

if (TimeFrame=="calculateTma") { calculatingTma=true; return(0); }
if (TimeFrame=="returnBars") { returningBars=true; return(0); }

IndicatorFileName = WindowExpertName();
return(0);
}
int deinit() { return(0); }

//+--------------------------- ------------------------------ ---------+
//| |
//+--------------------------- ------------------------------ ---------+
//
//
//
//
//

int start()
{
int counted_bars=IndicatorCounted( );
int i,limit;

if(counted_bars<0) return(-1);
if(counted_bars>0) counted_bars--;
limit=MathMin(Bars-1,Bars- counted_bars+HalfLength);

if (returningBars) { tmBuffer[0] = limit; return(0); }
if (calculatingTma) { calculateTma(limit); return(0); }
if (timeFrame > Period()) limit = MathMax(limit,MathMin(Bars-1, iCustom(NULL,timeFrame, IndicatorFileName,"returnBars" ,0,0)*timeFrame/Period()));

//
//
//
//
//

for(i = limit; i >= 0; i--)
{
int shift1 = iBarShift(NULL,timeFrame,Time[ i]);
datetime time1 = iTime (NULL,timeFrame,shift1);

//
//
//
//
//

tmBuffer[i] = iCustom(NULL,timeFrame, IndicatorFileName," calculateTma",HalfLength, Price,BandsDeviations,0, shift1);
upBuffer[i] = iCustom(NULL,timeFrame, IndicatorFileName," calculateTma",HalfLength, Price,BandsDeviations,1, shift1);
dnBuffer[i] = iCustom(NULL,timeFrame, IndicatorFileName," calculateTma",HalfLength, Price,BandsDeviations,2, shift1);

upArrow[i] = EMPTY_VALUE;
dnArrow[i] = EMPTY_VALUE;
if (High[i+1]>upBuffer[i+1] && Close[i+1]>Open[i+1] && Close[i]<Open[i]) upArrow[i] = High[i];
if (Low[i+1]<dnBuffer[i+1] && Close[i+1]<Open[i+1] && Close[i]>Open[i]) dnArrow[i] = Low[i];

if (timeFrame <= Period() || shift1==iBarShift(NULL, timeFrame,Time[i-1])) continue;
if (!Interpolate) continue;

//
//
//
//
//

for(int n = 1; i+n < Bars && Time[i+n] >= time1; n++) continue;
double factor = 1.0 / n;
for(int k = 1; k < n; k++)
{
tmBuffer[i+k] = k*factor*tmBuffer[i+n] + (1.0-k*factor)*tmBuffer[i];
upBuffer[i+k] = k*factor*upBuffer[i+n] + (1.0-k*factor)*upBuffer[i];
dnBuffer[i+k] = k*factor*dnBuffer[i+n] + (1.0-k*factor)*dnBuffer[i];
}
}

//
//
//
//
//

if (alertsOn)
{
if (alertsOnCurrent)
int forBar = 0;
else forBar = 1;
if (alertsOnHighLow)
{
if (High[forBar] > upBuffer[forBar] && High[forBar+1] < upBuffer[forBar+1]) doAlert("high penetrated upper bar");
if (Low[forBar] < dnBuffer[forBar] && Low[forBar+1] > dnBuffer[forBar+1]) doAlert("low penetrated lower bar");
}
else
{
if (Close[forBar] > upBuffer[forBar] && Close[forBar+1] < upBuffer[forBar+1]) doAlert("close penetrated upper bar");
if (Close[forBar] < dnBuffer[forBar] && Close[forBar+1] > dnBuffer[forBar+1]) doAlert("close penetrated lower bar");
}
}

return(0);
}

//+--------------------------- ------------------------------ ---------+
//| |
//+--------------------------- ------------------------------ ---------+
//
//
//
//
//

void calculateTma(int limit)
{
int i,j,k;
double FullLength = 2.0*HalfLength+1.0;

//
//
//
//
//

for (i=limit; i>=0; i--)
{
double sum = (HalfLength+1)*iMA(NULL,0,1,0, MODE_SMA,Price,i);
double sumw = (HalfLength+1);
for(j=1, k=HalfLength; j<=HalfLength; j++, k--)
{
sum += k*iMA(NULL,0,1,0,MODE_SMA, Price,i+j);
sumw += k;

if (j<=i)
{
sum += k*iMA(NULL,0,1,0,MODE_SMA, Price,i-j);
sumw += k;
}
}
tmBuffer[i] = sum/sumw;

//
//
//
//
//

double diff = iMA(NULL,0,1,0,MODE_SMA,Price, i)-tmBuffer[i];
if (i> (Bars-HalfLength-1)) continue;
if (i==(Bars-HalfLength-1))
{
upBuffer[i] = tmBuffer[i];
dnBuffer[i] = tmBuffer[i];
if (diff>=0)
{
wuBuffer[i] = MathPow(diff,2);
wdBuffer[i] = 0;
}
else
{
wdBuffer[i] = MathPow(diff,2);
wuBuffer[i] = 0;
}
continue;
}

//
//
//
//
//

if(diff>=0)
{
wuBuffer[i] = (wuBuffer[i+1]*(FullLength-1)+ MathPow(diff,2))/FullLength;
wdBuffer[i] = wdBuffer[i+1]*(FullLength-1)/ FullLength;
}
else
{
wdBuffer[i] = (wdBuffer[i+1]*(FullLength-1)+ MathPow(diff,2))/FullLength;
wuBuffer[i] = wuBuffer[i+1]*(FullLength-1)/ FullLength;
}
upBuffer[i] = tmBuffer[i] + BandsDeviations*MathSqrt( wuBuffer[i]);
dnBuffer[i] = tmBuffer[i] - BandsDeviations*MathSqrt( wdBuffer[i]);
}
}

//+--------------------------- ------------------------------ ---------+
//| |
//+--------------------------- ------------------------------ ---------+
//
//
//
//
//

void doAlert(string doWhat)
{
static string previousAlert="";
static datetime previousTime;
string message;

//
//
//
//
//

if (previousAlert!=doWhat || previousTime!=Time[0])
{
previousAlert = doWhat;
previousTime = Time[0];

message= StringConcatenate(Symbol()," at ",TimeToStr(TimeLocal(),TIME_ SECONDS)," THA : ",doWhat);
if (alertsMessage) Alert(message);
if (alertsEmail) SendMail(StringConcatenate( Symbol(),"TMA "),message);
if (alertsSound) PlaySound("alert2.wav");
}
}

//
//
//
//
//

int stringToTimeFrame(string tfs)
{
for(int l = StringLen(tfs)-1; l >= 0; l--)
{
int char2 = StringGetChar(tfs,l);
if((char2 > 96 && char2 < 123) || (char2 > 223 && char2 < 256))
tfs = StringSetChar(tfs, 1, char2 - 32);
else
if(char2 > -33 && char2 < 0)
tfs = StringSetChar(tfs, 1, char2 + 224);
}
int tf=0;
if (tfs=="M1" || tfs=="1") tf=PERIOD_M1;
if (tfs=="M5" || tfs=="5") tf=PERIOD_M5;
if (tfs=="M15"|| tfs=="15") tf=PERIOD_M15;
if (tfs=="M30"|| tfs=="30") tf=PERIOD_M30;
if (tfs=="H1" || tfs=="60") tf=PERIOD_H1;
if (tfs=="H4" || tfs=="240") tf=PERIOD_H4;
if (tfs=="D1" || tfs=="1440") tf=PERIOD_D1;
if (tfs=="W1" || tfs=="10080") tf=PERIOD_W1;
if (tfs=="MN" || tfs=="43200") tf=PERIOD_MN1;
if (tf==0 || tf<Period()) tf=Period();
return(tf);
}

Keith Watford 2020.12.10 06:58 #1

Please edit your post and use the code button (Alt+S) when pasting code.

EDIT your original post, please do not just post the code properly in a new post.

William Roeder 2020.12.10 15:19 #2

Please edit your (original) post and use the CODE button (Alt-S)! (For large amounts of code, attach it.)
General rules and best pratices of the Forum. - General - MQL5 programming forum 2019.05.06
Messages Editor

Your posted code is broken.

if (TimeFrame=="calculateTma")  { calculatingTma=true; return(0); }
⋮
tmBuffer[i] = iCustom(NULL,timeFrame, IndicatorFileName," calculateTma",HalfLength, Price,BandsDeviations,0, shift1);
upBuffer[i] = iCustom(NULL,timeFrame, IndicatorFileName," calculateTma",HalfLength, Price,BandsDeviations,1, shift1);
dnBuffer[i] = iCustom(NULL,timeFrame, IndicatorFileName," calculateTma",HalfLength, Price,BandsDeviations,2, shift1);

The iCustom calls has a space.

drlarryvon: Can anyone with some knowledge explain how the bands are calculated, please.
```
 double diff = iMA(NULL,0,1,0,MODE_SMA,Price, i)-tmBuffer[i]; 
```
TMA ± Standard deviation(TMA-SMA) × BandsDeviations.

need help for loop Simple Indicator Code Question Error inserting indicator alert

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