想做一个另类的移动平均线指标(Moving Average),请大家高手指导。

[郑美援]

想根据现在的移动平均线做一个另类的移动平均线指标(Moving Average)，它只在特定的条件下显示，其他时候不显示。特定条件如下:

比如，以30周期的移动平均线为例，姑且叫它"MA30"。设当前周期(或是当前柱线)的移动平均线值是MA30，设前一周期(或是前一柱线)的移动平均线值是MA30-1。

当条件 Abs（MA30-MA30-1)/MA30*100<0.005 成立时，显示移动平均线MA30，条件不成立时不显示(换句话讲，只显示部分移动平均线)。

现在使用的移动平均线源码如下，请前辈高手帮忙将上面的条件加进去。在此先谢谢您们了。

//+------------------------------------------------------------------+
//| Custom Moving Average.mq4 |
//| Copyright ?2004, MetaQuotes Software Corp. |
//| https://www.metaquotes.net// |
//+------------------------------------------------------------------+
#property copyright "Copyright ?2004, MetaQuotes Software Corp."
#property link "https://www.metaquotes.net//"

#property indicator_chart_window
#property indicator_buffers 1
#property indicator_color1 Red
//---- indicator parameters
extern int MA_Period=13;
extern int MA_Shift=0;
extern int MA_Method=0;
//---- indicator buffers
double ExtMapBuffer[];
//----
int ExtCountedBars=0;
//+------------------------------------------------------------------+
//| Custom indicator initialization function |
//+------------------------------------------------------------------+
int init()
{
int draw_begin;
string short_name;
//---- drawing settings
SetIndexStyle(0,DRAW_LINE);
SetIndexShift(0,MA_Shift);
IndicatorDigits(MarketInfo(Symbol(),MODE_DIGITS));
if(MA_Period<2) MA_Period=13;
draw_begin=MA_Period-1;
//---- indicator short name
switch(MA_Method)
{
case 1 : short_name="EMA("; draw_begin=0; break;
case 2 : short_name="SMMA("; break;
case 3 : short_name="LWMA("; break;
default :
MA_Method=0;
short_name="SMA(";
}
IndicatorShortName(short_name+MA_Period+")");
SetIndexDrawBegin(0,draw_begin);
//---- indicator buffers mapping
SetIndexBuffer(0,ExtMapBuffer);
//---- initialization done
return(0);
}
//+------------------------------------------------------------------+
//| |
//+------------------------------------------------------------------+
int start()
{
if(Bars<=MA_Period) return(0);
ExtCountedBars=IndicatorCounted();
//---- check for possible errors
if (ExtCountedBars<0) return(-1);
//---- last counted bar will be recounted
if (ExtCountedBars>0) ExtCountedBars--;
//----
switch(MA_Method)
{
case 0 : sma(); break;
case 1 : ema(); break;
case 2 : smma(); break;
case 3 : lwma();
}
//---- done
return(0);
}
//+------------------------------------------------------------------+
//| Simple Moving Average |
//+------------------------------------------------------------------+
void sma()
{
double sum=0;
int i,pos=Bars-ExtCountedBars-1;
//---- initial accumulation
if(pos<MA_Period) pos=MA_Period;
for(i=1;i<MA_Period;i++,pos--)
sum+=Close[pos];
//---- main calculation loop
while(pos>=0)
{
sum+=Close[pos];
ExtMapBuffer[pos]=sum/MA_Period;
sum-=Close[pos+MA_Period-1];
pos--;
}
//---- zero initial bars
if(ExtCountedBars<1)
for(i=1;i<MA_Period;i++) ExtMapBuffer[Bars-i]=0;
}
//+------------------------------------------------------------------+
//| Exponential Moving Average |
//+------------------------------------------------------------------+
void ema()
{
double pr=2.0/(MA_Period+1);
int pos=Bars-2;
if(ExtCountedBars>2) pos=Bars-ExtCountedBars-1;
//---- main calculation loop
while(pos>=0)
{
if(pos==Bars-2) ExtMapBuffer[pos+1]=Close[pos+1];
ExtMapBuffer[pos]=Close[pos]*pr+ExtMapBuffer[pos+1]*(1-pr);
pos--;
}
}
//+------------------------------------------------------------------+
//| Smoothed Moving Average |
//+------------------------------------------------------------------+
void smma()
{
double sum=0;
int i,k,pos=Bars-ExtCountedBars+1;
//---- main calculation loop
pos=Bars-MA_Period;
if(pos>Bars-ExtCountedBars) pos=Bars-ExtCountedBars;
while(pos>=0)
{
if(pos==Bars-MA_Period)
{
//---- initial accumulation
for(i=0,k=pos;i<MA_Period;i++,k++)
{
sum+=Close[k];
//---- zero initial bars
ExtMapBuffer[k]=0;
}
}
else sum=ExtMapBuffer[pos+1]*(MA_Period-1)+Close[pos];
ExtMapBuffer[pos]=sum/MA_Period;
pos--;
}
}
//+------------------------------------------------------------------+
//| Linear Weighted Moving Average |
//+------------------------------------------------------------------+
void lwma()
{
double sum=0.0,lsum=0.0;
double price;
int i,weight=0,pos=Bars-ExtCountedBars-1;
//---- initial accumulation
if(pos<MA_Period) pos=MA_Period;
for(i=1;i<=MA_Period;i++,pos--)
{
price=Close[pos];
sum+=price*i;
lsum+=price;
weight+=i;
}
//---- main calculation loop
pos++;
i=pos+MA_Period;
while(pos>=0)
{
ExtMapBuffer[pos]=sum/weight;
if(pos==0) break;
pos--;
i--;
price=Close[pos];
sum=sum-lsum+price*MA_Period;
lsum-=Close[i];
lsum+=price;
}
//---- zero initial bars
if(ExtCountedBars<1)
for(i=1;i<MA_Period;i++) ExtMapBuffer[Bars-i]=0;
}
//+------------------------------------------------------------------+