Custom Indicator Functions

kokas · 10-23-2006, 02:31 PM

Custom Indicator functions

void IndicatorBuffers(
int count)

Allocates memory for buffers used for custom indicator calculations. Cannot be greater than 8 and less than indicator_buffers property. If custom indicator requires additional buffers for counting then use this function for pointing common buffers count.

Parameters

count
-
Buffers count to allocate. Should be up to 8 buffers.

Sample
#property indicator_separate_window
#property indicator_buffers 1
#property indicator_color1 Silver
//---- indicator parameters
extern int FastEMA=12;
extern int SlowEMA=26;
extern int SignalSMA=9;
//---- indicator buffers
double ind_buffer1[];
double ind_buffer2[];
double ind_buffer3[];
//+------------------------------------------------------------------+
//| Custom indicator initialization function |
//+------------------------------------------------------------------+
int init()
{
//---- 2 additional buffers are used for counting.
IndicatorBuffers(3);
//---- drawing settings
SetIndexStyle(0,DRAW_HISTOGRAM,STYLE_SOLID,3);
SetIndexDrawBegin(0,SignalSMA);
IndicatorDigits(MarketInfo(Symbol(),MODE_DIGITS)+2 );
//---- 3 indicator buffers mapping
SetIndexBuffer(0,ind_buffer1);
SetIndexBuffer(1,ind_buffer2);
SetIndexBuffer(2,ind_buffer3);
//---- name for DataWindow and indicator subwindow label
IndicatorShortName("OsMA("+FastEMA+","+SlowEMA+"," +SignalSMA+")");
//---- initialization done
return(0);
}

int IndicatorCounted(
)

Returns bars count that does not changed after last indicator launch. In most cases same count of index values do not need for recalculation. Used for optimizing calculations.

Sample
int start()
{
int limit;
int counted_bars=IndicatorCounted();
//---- check for possible errors
if(counted_bars<0) return(-1);
//---- last counted bar will be recounted
if(counted_bars>0) counted_bars--;
limit=Bars-counted_bars;
//---- main loop
for(int i=0; i<limit; i++)
{
//---- ma_shift set to 0 because SetIndexShift called abowe
ExtBlueBuffer[i]=iMA(NULL,0,JawsPeriod,0,MODE_SMMA,PRICE_MEDIAN,i) ;
ExtRedBuffer[i]=iMA(NULL,0,TeethPeriod,0,MODE_SMMA,PRICE_MEDIAN,i );
ExtLimeBuffer[i]=iMA(NULL,0,LipsPeriod,0,MODE_SMMA,PRICE_MEDIAN,i) ;
}
//---- done
return(0);
}

void IndicatorDigits(
int digits)

Sets default precision format for indicators visualization.

Parameters

digits
-
Precision format, number of digits after decimal point.

Sample
#property indicator_separate_window
#property indicator_buffers 1
#property indicator_color1 Silver
//---- indicator parameters
extern int FastEMA=12;
extern int SlowEMA=26;
extern int SignalSMA=9;
//---- indicator buffers
double ind_buffer1[];
double ind_buffer2[];
double ind_buffer3[];
//+------------------------------------------------------------------+
//| Custom indicator initialization function |
//+------------------------------------------------------------------+
int init()
{
//---- 2 additional buffers are used for counting.
IndicatorBuffers(3);
//---- drawing settings
SetIndexStyle(0,DRAW_HISTOGRAM,STYLE_SOLID,3);
SetIndexDrawBegin(0,SignalSMA);
IndicatorDigits(MarketInfo(Symbol(),MODE_DIGITS)+2 );
//---- 3 indicator buffers mapping
SetIndexBuffer(0,ind_buffer1);
SetIndexBuffer(1,ind_buffer2);
SetIndexBuffer(2,ind_buffer3);
//---- name for DataWindow and indicator subwindow label
IndicatorShortName("OsMA("+FastEMA+","+SlowEMA+"," +SignalSMA+")");
//---- initialization done
return(0);
}

void IndicatorShortName(
string name)

Sets indicator short name for showing on the chart subwindow.

Parameters

name
-
New short name.

Sample
#property indicator_separate_window
#property indicator_buffers 1
#property indicator_color1 Silver
//---- indicator parameters
extern int FastEMA=12;
extern int SlowEMA=26;
extern int SignalSMA=9;
//---- indicator buffers
double ind_buffer1[];
double ind_buffer2[];
double ind_buffer3[];
//+------------------------------------------------------------------+
//| Custom indicator initialization function |
//+------------------------------------------------------------------+
int init()
{
//---- 2 additional buffers are used for counting.
IndicatorBuffers(3);
//---- drawing settings
SetIndexStyle(0,DRAW_HISTOGRAM,STYLE_SOLID,3);
SetIndexDrawBegin(0,SignalSMA);
IndicatorDigits(MarketInfo(Symbol(),MODE_DIGITS)+2 );
//---- 3 indicator buffers mapping
SetIndexBuffer(0,ind_buffer1);
SetIndexBuffer(1,ind_buffer2);
SetIndexBuffer(2,ind_buffer3);
//---- name for DataWindow and indicator subwindow label
IndicatorShortName("OsMA("+FastEMA+","+SlowEMA+"," +SignalSMA+")");
//---- initialization done
return(0);
}

void SetIndexArrow(
int index, int code)

Sets arrow symbol for indicators that draws some lines as arrow.

Parameters

index
-
Line index. Should be from 0 to 7.
code
-
Symbol code from Wingdings font or Array constants.

Sample
SetIndexArrow(0, 217);

bool SetIndexBuffer(
int index, double array[])

Sets buffer for calculating line. The indicated array bound with previously allocated custom indicator buffer. If the function succeeds, the return value is true. If the function fails, the return value is false. To get the detailed error information, call GetLastError().

Parameters

index
-
Line index. Should be from 0 to 7.
array[]
-
Array that stores calculated indicator values.

Sample
double ExtBufferSilver[];
int init()
{
SetIndexBuffer(0, ExtBufferSilver); // set buffer for first line
// ...
}

void SetIndexDrawBegin(
int index, int begin)

Sets first bar from what index will be drawn. Index values before draw begin are not significant and does not drawn and not show in the DataWindow.

Parameters

index
-
Line index. Should be from 0 to 7.
begin
-
First drawing bar position number.

Sample
#property indicator_separate_window
#property indicator_buffers 1
#property indicator_color1 Silver
//---- indicator parameters
extern int FastEMA=12;
extern int SlowEMA=26;
extern int SignalSMA=9;
//---- indicator buffers
double ind_buffer1[];
double ind_buffer2[];
double ind_buffer3[];
//+------------------------------------------------------------------+
//| Custom indicator initialization function |
//+------------------------------------------------------------------+
int init()
{
//---- 2 additional buffers are used for counting.
IndicatorBuffers(3);
//---- drawing settings
SetIndexStyle(0,DRAW_HISTOGRAM,STYLE_SOLID,3);
SetIndexDrawBegin(0,SignalSMA);
IndicatorDigits(MarketInfo(Symbol(),MODE_DIGITS)+2 );
//---- 3 indicator buffers mapping
SetIndexBuffer(0,ind_buffer1);
SetIndexBuffer(1,ind_buffer2);
SetIndexBuffer(2,ind_buffer3);
//---- name for DataWindow and indicator subwindow label
IndicatorShortName("OsMA("+FastEMA+","+SlowEMA+"," +SignalSMA+")");
//---- initialization done
return(0);
}

void SetIndexEmptyValue(
int index, double value)

Sets drawing line empty value. By default, empty value line is EMPTY_VALUE. Empty values are not drawn and not show in the DataWindow.

Parameters

index
-
Line index. Should be from 0 to 7.
value
-
New empty value.

Sample
SetIndexEmptyValue(6,0.0001);

void SetIndexLabel(
int index, string text)

Sets drawing line description for showing in the DataWindow.

Parameters

index
-
Line index. Should be from 0 to 7.
text
-
Label text. NULL means that index value does not show in the DataWindow.

Sample
//+------------------------------------------------------------------+
//| Ichimoku Kinko Hyo initialization function |
//+------------------------------------------------------------------+
int init()
{
//----
SetIndexStyle(0,DRAW_LINE);
SetIndexBuffer(0,Tenkan_Buffer);
SetIndexDrawBegin(0,Tenkan-1);
SetIndexLabel(0,"Tenkan Sen");
//----
SetIndexStyle(1,DRAW_LINE);
SetIndexBuffer(1,Kijun_Buffer);
SetIndexDrawBegin(1,Kijun-1);
SetIndexLabel(1,"Kijun Sen");
//----
a_begin=Kijun; if(a_begin<Tenkan) a_begin=Tenkan;
SetIndexStyle(2,DRAW_HISTOGRAM,STYLE_DOT);
SetIndexBuffer(2,SpanA_Buffer);
SetIndexDrawBegin(2,Kijun+a_begin-1);
SetIndexShift(2,Kijun);
//---- Up Kumo bounding line does not show in the DataWindow
SetIndexLabel(2,NULL);
SetIndexStyle(5,DRAW_LINE,STYLE_DOT);
SetIndexBuffer(5,SpanA2_Buffer);
SetIndexDrawBegin(5,Kijun+a_begin-1);
SetIndexShift(5,Kijun);
SetIndexLabel(5,"Senkou Span A");
//----
SetIndexStyle(3,DRAW_HISTOGRAM,STYLE_DOT);
SetIndexBuffer(3,SpanB_Buffer);
SetIndexDrawBegin(3,Kijun+Senkou-1);
SetIndexShift(3,Kijun);
//---- Down Kumo bounding line does not show in the DataWindow
SetIndexLabel(3,NULL);
//----
SetIndexStyle(6,DRAW_LINE,STYLE_DOT);
SetIndexBuffer(6,SpanB2_Buffer);
SetIndexDrawBegin(6,Kijun+Senkou-1);
SetIndexShift(6,Kijun);
SetIndexLabel(6,"Senkou Span B");
//----
SetIndexStyle(4,DRAW_LINE);
SetIndexBuffer(4,Chinkou_Buffer);
SetIndexShift(4,-Kijun);
SetIndexLabel(4,"Chinkou Span");
//----
return(0);
}

void SetIndexShift(
int index, int shift)

Sets offset for drawing line. Line will be counted on the current bar, but will be drawn shifted.

Parameters

index
-
Line index. Should be from 0 to 7.
shift
-
Shitf value in bars.

Sample
//+------------------------------------------------------------------+
//| Alligator initialization function |
//+------------------------------------------------------------------+
int init()
{
//---- line shifts when drawing
SetIndexShift(0,JawsShift);
SetIndexShift(1,TeethShift);
SetIndexShift(2,LipsShift);
//---- first positions skipped when drawing
SetIndexDrawBegin(0,JawsShift+JawsPeriod);
SetIndexDrawBegin(1,TeethShift+TeethPeriod);
SetIndexDrawBegin(2,LipsShift+LipsPeriod);
//---- 3 indicator buffers mapping
SetIndexBuffer(0,ExtBlueBuffer);
SetIndexBuffer(1,ExtRedBuffer);
SetIndexBuffer(2,ExtLimeBuffer);
//---- drawing settings
SetIndexStyle(0,DRAW_LINE);
SetIndexStyle(1,DRAW_LINE);
SetIndexStyle(2,DRAW_LINE);
//---- index labels
SetIndexLabel(0,"Gator Jaws");
SetIndexLabel(1,"Gator Teeth");
SetIndexLabel(2,"Gator Lips");
//---- initialization done
return(0);
}

void SetIndexStyle(
int index, int type, int style=EMPTY, int width=EMPTY, color clr=CLR_NONE)

Sets new type, style, width and color for a given indicator line.

Parameters

index
-
Line index. Should be from 0 to 7.
type
-
Shape style.Can be one of Drawing shape style enumeration.
style
-
Drawing style. Except STYLE_SOLID style all other styles valid when width is 1 pixel.Can be one of Shape style enumeration. EMPTY value indicates that style does not changed.
width
-
Line width. valid values - 1,2,3,4,5. EMPTY value indicates that width does not changed.
clr
-
Line color.

Sample
SetIndexStyle(3, DRAW_LINE, EMPTY, 2, Red);

void SetLevelStyle(
int draw_style, int line_width, color clr=CLR_NONE)

Function sets new style, width and color of indicator levels.

Parameters

draw_style
-
Drawing style. Except for STYLE_SOLID, all other styles are valid if the width is 1 pixel.Can be one of Shape style constants.EMPTY value indicates that style will not be changed.
line_width
-
Line width. Valid values are 1,2,3,4,5. EMPTY value indicates that width will not be changed.
clr
-
Line color.

Sample
//---- show levels as thick red lines
SetLevelStyle(STYLE_SOLID,2,Red)

int SetLevelValue(
int level, double value)

Function sets a new value for the given indicator level.

Parameters

level
-
Level index (0-31).
value
-
Value for the given indicator level.

Sample
SetLevelValue(1,3.14);