Indicator Not Drawing on Chart

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This Donchian Channels indicator, which appears to be operating properly, is not drawing the channels on my chart. In the past it has drawn the channels as configured. Now suddenly, it is not.



//+------------------------------------------------------------------+
//| DonchianChannels.mq4 |
//| Copyright © 2005, Luis Guilherme Damiani |
//| http://www.damianifx.com.br |
//+------------------------------------------------------------------+
#property copyright "Copyright © 2005, Luis Guilherme Damiani"
#property link "http://www.damianifx.com.br"

#property indicator_chart_window
#property indicator_buffers 2
#property indicator_color1 Magenta
#property indicator_color2 Magenta

//Periods: number of bars used for calculating the Donchian channel
//Extremes: if 1 uses the highest high and the lowest low -> I do not recomend using this
// if 0 uses the open of the extremes bar -> the open point of a bar (as well as the close
// are the points of maximum probability of concentration of the prices during the bar
// if 3 uses the median point most extreme open and lowest low or highest high
//Margins: is the percent of the channel subtrated from the channel border before printing it, negative values are allowed
//Advance: the numbers of bars ahead
//---- input parameters
extern int Periods=24;
extern int Extremes=3;
extern int Margins=-2;
extern int Advance=0;
extern int max_bars=700;
//---- buffers
double ExtMapBuffer1[];
double ExtMapBuffer2[];
//+------------------------------------------------------------------+
//| Custom indicator initialization function |
//+------------------------------------------------------------------+
int init()
{
//---- indicators
SetIndexStyle(0,DRAW_LINE,1,2);
SetIndexBuffer(0,ExtMapBuffer1);
SetIndexStyle(1,DRAW_LINE,1,2);
SetIndexBuffer(1,ExtMapBuffer2);

//----
return(0);
}
//+------------------------------------------------------------------+
//| Custor indicator deinitialization function |
//+------------------------------------------------------------------+
int deinit()
{
//----

//----
return(0);
}
//+------------------------------------------------------------------+
//| Custom indicator iteration function |
//+------------------------------------------------------------------+
int start()
{
int fixed_bars=IndicatorCounted();
//----

//int shift=0;//, cnt(0), loopbegin(0);
double smin=0, smax=0, SsMax=0, SsMin=0;
//Variables : bar(0), prevbars(0), start(0), cs(0), prevcs(0),commodt(0);

for (int shift=0;shift< max_bars;shift++)
{
if (Extremes ==1)
{
SsMax = High[Highest(NULL,0,MODE_HIGH,Periods,shift)];
SsMin = Low[Lowest(NULL,0,MODE_LOW,Periods,shift)];
}
else if (Extremes == 3)
{
SsMax = (Open[Highest(NULL,0,MODE_OPEN,Periods,shift)]+High[Highest(NULL,0,MODE_HIGH,Periods,shift)])/2;
SsMin = (Open[Lowest(NULL,0,MODE_OPEN,Periods,shift)]+Low[Lowest(NULL,0,MODE_LOW,Periods,shift)])/2;
}
else
{
SsMax = Open[Highest(NULL,0,MODE_OPEN,Periods,shift)];
SsMin = Open[Lowest(NULL,0,MODE_OPEN,Periods,shift)];
}
smin = SsMin+(SsMax-SsMin)*Margins/100;
smax = SsMax-(SsMax-SsMin)*Margins/100;
ExtMapBuffer1[shift-Advance]=smin;
ExtMapBuffer2[shift-Advance]=smax;
}
//----
return(0);
}
//+------------------------------------------------------------------+
 
More specifically, the indicator does not draw on all the bars for a given chart...seems to only draw on roughly the last six months of bars. Ideally, it would draw on the entire bar range that is being tested.

Is there a way to specify that in Metatrader/MQL?
 
More specifically, the indicator does not draw on all the bars for a given chart...seems to only draw on roughly the last six months of bars. Ideally, it would draw on the entire bar range that is being tested.

Is there a way to specify that in Metatrader/MQL?




The main loop of the indicator is the block of code that follows

for (int shift=0;shift< max_bars;shift++)

Since max_bars is an input parameter that defaults to 700, the indicator only draws 700 bars back. Change max_bars to a higher number to see more.

If you want to see every bar in the history center, then change the above line to

for (int shift=0;shift< fixed_bars;shift++)
 
With your proposed changes, the indicator draws across the entire bar history. Thanks!
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