//+------------------------------------------------------------------+
//| DRAW_HISTOGRAM.mq5 |
//| Copyright 2011, MetaQuotes Software Corp. |
//| https://www.mql5.com |
//+------------------------------------------------------------------+
#property copyright "Copyright 2000-2024, MetaQuotes Ltd."
#property link "https://www.mql5.com"
#property version "1.00"
#property description "An indicator to demonstrate DRAW_HISTOGRAM"
#property description "It draws a sinusoid as a histogram in a separate window"
#property description "The color and width of columns are changed randomly"
#property description "after every N ticks"
#property description "The bars parameter sets the number of bars in the cycle of the sinusoid"
#property indicator_separate_window
#property indicator_buffers 1
#property indicator_plots 1
//--- plot Histogram
#property indicator_label1 "Histogram"
#property indicator_type1 DRAW_HISTOGRAM
#property indicator_color1 clrBlue
#property indicator_style1 STYLE_SOLID
#property indicator_width1 1
//--- input parameters
input int bars=30; // The period of a sinusoid in bars
input int N=5; // The number of ticks to change the histogram
//--- indicator buffers
double HistogramBuffer[];
//--- A factor to get the 2Pi angle in radians, when multiplied by the bars parameter
double multiplier;
//--- An array to store colors
color colors[]={clrRed,clrBlue,clrGreen};
//--- An array to store the line styles
ENUM_LINE_STYLE styles[]={STYLE_SOLID,STYLE_DASH,STYLE_DOT,STYLE_DASHDOT,STYLE_DASHDOTDOT};
//+------------------------------------------------------------------+
//| Custom indicator initialization function |
//+------------------------------------------------------------------+
int OnInit()
{
//--- indicator buffers mapping
SetIndexBuffer(0,HistogramBuffer,INDICATOR_DATA);
//--- Calculate the multiplier
if(bars>1)multiplier=2.*M_PI/bars;
else
{
PrintFormat("Set the value of bars=%d greater than 1",bars);
//--- Early termination of the indicator
return(INIT_PARAMETERS_INCORRECT);
}
//---
return(INIT_SUCCEEDED);
}
//+------------------------------------------------------------------+
//| Custom indicator iteration function |
//+------------------------------------------------------------------+
int OnCalculate(const int rates_total,
const int prev_calculated,
const datetime &time[],
const double &open[],
const double &high[],
const double &low[],
const double &close[],
const long &tick_volume[],
const long &volume[],
const int &spread[])
{
static int ticks=0;
//--- Calculate ticks to change the style, color and width of the line
ticks++;
//--- If a critical number of ticks has been accumulated
if(ticks>=N)
{
//--- Change the line properties
ChangeLineAppearance();
//--- Reset the counter of ticks to zero
ticks=0;
}
//--- Calculate the indicator values
int start=0;
//--- If already calculated during the previous starts of OnCalculate
if(prev_calculated>0) start=prev_calculated-1; // set the beginning of the calculation with the last but one bar
//--- Fill in the indicator buffer with values
for(int i=start;i<rates_total;i++)
{
HistogramBuffer[i]=sin(i*multiplier);
}
//--- Return the prev_calculated value for the next call of the function
return(rates_total);
}
//+------------------------------------------------------------------+
//| Changes the appearance of lines in the indicator |
//+------------------------------------------------------------------+
void ChangeLineAppearance()
{
//--- A string for the formation of information about the line properties
string comm="";
//--- A block for changing the color of the line
int number=MathRand(); // Get a random number
//--- The divisor is equal to the size of the colors[] array
int size=ArraySize(colors);
//--- Get the index to select a new color as the remainder of integer division
int color_index=number%size;
//--- Set the color as the PLOT_LINE_COLOR property
PlotIndexSetInteger(0,PLOT_LINE_COLOR,colors[color_index]);
//--- Write the line color
comm=comm+"\r\n"+(string)colors[color_index];
//--- A block for changing the width of the line
number=MathRand();
//--- Get the width of the remainder of integer division
int width=number%5; // The width is set from 0 to 4
//--- Set the width
PlotIndexSetInteger(0,PLOT_LINE_WIDTH,width);
//--- Write the line width
comm=comm+"\r\nWidth="+IntegerToString(width);
//--- A block for changing the style of the line
number=MathRand();
//--- The divisor is equal to the size of the styles array
size=ArraySize(styles);
//--- Get the index to select a new style as the remainder of integer division
int style_index=number%size;
//--- Set the line style
PlotIndexSetInteger(0,PLOT_LINE_STYLE,styles[style_index]);
//--- Write the line style
comm="\r\n"+EnumToString(styles[style_index])+""+comm;
//--- Show the information on the chart using a comment
Comment(comm);
} |
