Please Help with this Code, loooks promising

Why is the code below not plotting consistently i.e., sometimes it plots the histogram, and other times it doesnt? Plus is it cheating when it plots, ie. uses future data in its calculations? Thanks

Liz

//+------------------------------------------------------------------+
//| CoeffofLine.mq4 |
//| Ramdass - Conversion only |
//+------------------------------------------------------------------+
#property indicator_separate_window
#property indicator_buffers 1
#property indicator_color1 Blue
//----
extern int ndot = 5;
extern int CountBars = 300;
//---- buffers
double cfl[];
//+------------------------------------------------------------------+
//| Custom indicator initialization function |
//+------------------------------------------------------------------+
int init()
{
//---- indicator line
SetIndexStyle(0, DRAW_HISTOGRAM);
SetIndexBuffer(0, cfl);
//----
IndicatorShortName("CoeffofLine(" + ndot + ")");
//----
if(CountBars >= Bars)
CountBars=Bars;
SetIndexDrawBegin(0, Bars - CountBars + ndot + 1);
//----
return(0);
}
//+------------------------------------------------------------------+
//| CoeffofLine_v1 |
//+------------------------------------------------------------------+
int start()
{
int i, shift, cnt, ndot1, counted_bars = IndicatorCounted();
double TYVar, ZYVar, TIndicatorVar, ZIndicatorVar, M, N, AY, AIndicator;
//----
if(Bars <= ndot)
return(0);
//----
if(counted_bars < ndot)
return(0);
shift = Bars - CountBars - ndot - 1;
//----
while(shift >= 0)
{
TYVar = 0;
ZYVar = 0;
N = 0;
M = 0;
TIndicatorVar = 0;
ZIndicatorVar = 0;
ndot1 = ndot;
//----
if(shift + 1 < ndot1)
ndot1 = shift + 1;
//----
for(cnt = ndot; cnt >= 1; cnt--) // n=5 - ïî ïÿòè òî÷êàì
{
N = N + cnt*cnt; //ðàâíî 55
M = M + cnt; //ðàâíî 15
}
//----
for(cnt = ndot1; cnt >= 1; cnt--) // n=5 - ïî ïÿòè òî÷êàì
{
ZYVar = ZYVar + (High[shift-cnt+1] + Low[shift-cnt+1]) / 2*(ndot + 1 - cnt);
TYVar = TYVar + (High[shift-cnt+1] + Low[shift-cnt+1]) / 2;
ZIndicatorVar = ZIndicatorVar + iMA(NULL, 0, 5, 3, MODE_SMMA, PRICE_MEDIAN,
shift - cnt + 1)*(ndot + 1 - cnt);
TIndicatorVar = TIndicatorVar + iMA(NULL, 0, 5, 3, MODE_SMMA, PRICE_MEDIAN,
shift - cnt + 1);
}
AY = (TYVar + (N - 2*ZYVar)*ndot / M) / M;
AIndicator = (TIndicatorVar + (N - 2*ZIndicatorVar)*ndot / M) / M;
//----
if(Symbol() == "EURUSD" || Symbol() == "GBPUSD" || Symbol() == "USDCAD" ||
Symbol() == "USDCHF" || Symbol() == "EURGBP" || Symbol() == "EURCHF" ||
Symbol() == "AUDUSD" || Symbol() == "GBPCHF")
{
cfl[shift] = (-1000)*MathLog(AY / AIndicator);
}
else
{
cfl[shift] = (1000)*MathLog(AY / AIndicator);
}
shift--;
}
return(0);
}
//+------------------------------------------------------------------+