Indicator not displaying

Hello

I'm a newbie at MT4 coding. I'm trying to help a friend set up some indicators and EA's. This is one code of an indicator and for some reason it does not display on the screen - and we can't tell why. Can anyone assist, please -- and Thank You in advance!!!

//------------------+
//Ehlers_ZeroLag_Filter.mq4
//------------------+
#property indicator_chart_window
#property indicator_buffers 1
#property indicator_plots 1
//---plot zerolag filter
#property indicator_label1 "ZeroLagFit"
#property indicator_type1 DRAW_LINE
#property indicator_color1 clrLimeGreen
#property indicator_style1 STYLE_SOLID
#property indicator_width1 1
//---input paramaters
input double alpha = .33;
//---indicator buffers
double ZeroLagFiltBuffer[];
double Price[];
int OnInit()
{
//---indicator buffer mapping
IndicatorBuffers(1);
SetIndexStyle(0,DRAW_LINE);
SetIndexBuffer(0,ZeroLagFiltBuffer);
SetIndexDrawBegin(0,DRAW_LINE);
return(INIT_SUCCEEDED);
}
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[])
{
//---
ArraySetAsSeries(high,true);
ArraySetAsSeries(low,true);
ArraySetAsSeries(Price,true);
ArraySetAsSeries(ZeroLagFiltBuffer,true);
int bars = rates_total - 1;
if(prev_calculated > 0) bars = rates_total - prev_calculated;
for(int i = bars; i >= 0; i--)
{
Price[i] = (high[i] + low[i]) * .5;
ZeroLagFiltBuffer[i] = alpha * (Price[i] + .5 * (Price[i] - Price[i+3])) + (1 - alpha) * ZeroLagFiltBuffer[i+1];
}
//---return value of prev_calculated for next call
return(rates_total);

Try this...

Thank you VERY MUCH!!!!

greatly appreciate the help!

Here is another indicator not displaying. I tried to replicate what the other did, but can't seem to understand why it isn't displaying. We appreciate the help!!!

I see a few have downloaded --- can you see/edit it, or do I need to copy the code as a post to help?
I greatly appreciate any help!!!

Here is the code in case the file had an issue... Thanks again!!!

//+------------------------------------------------------------------+
//| Instantaneous_Trendline.mq4 |
//| Copyright 2019, MetaQuotes Software Corp. |
//| https://www.mql5.com |
//+------------------------------------------------------------------+
//+---------------------------------+
//---Instantaneous_Trendline.mq4
//---Tony Thompson
//+---------------------------------+
#property version "1.00"
#property strict
#property indicator_chart_window
#property indicator_buffers 1
#property indicator_plots 1
//--- plot iTrendline
#property indicator_label1 "Trendline"
#property indicator_type1 DRAW_LINE
#property indicator_color1 clrBlue
#property indicator_style1 STYLE_SOLID
#property indicator_width1 2
//---Input Parameters
input double CycPart = 1;
//--- indicator buffers
double Trendline[];
//---working indcator/buffers
double price[];
double smooth[];
double detrender[];
double i1[];
double q1[];
double i2[];
double q2[];
double re[];
double im[];
double period[];
double smoothPeriod[];
double iTrend[];
//-----------------------------------------------------+
//---custom indicator initialization function
//-----------------------------------------------------+
int Onint()
{
//---indicator buffers mapping
IndicatorBuffers (13);
SetIndexStyle(0, DRAW_LINE);
SetIndexBuffer(0, Trendline);
SetIndexDrawBegin(0, DRAW_LINE);
SetIndexStyle(1, DRAW_NONE);
SetIndexBuffer(1, price);
SetIndexStyle(2, DRAW_NONE);
SetIndexBuffer(2, smooth);
SetIndexStyle(3, DRAW_NONE);
SetIndexBuffer(3, detrender);
SetIndexStyle(4, DRAW_NONE);
SetIndexBuffer(4, i1);
SetIndexStyle(5, DRAW_NONE);
SetIndexBuffer(5, q1);
SetIndexStyle(6, DRAW_NONE);
SetIndexBuffer(6, i2);
SetIndexStyle(7, DRAW_NONE);
SetIndexBuffer(7, q2);
SetIndexStyle(8, DRAW_NONE);
SetIndexBuffer(8, re);
SetIndexStyle(9, DRAW_NONE);
SetIndexBuffer(9, im);
SetIndexStyle(10, DRAW_NONE);
SetIndexBuffer(10, period);
SetIndexStyle(11, DRAW_NONE);
SetIndexBuffer(11, smoothPeriod);
SetIndexStyle(12, DRAW_LINE);
SetIndexBuffer(12, iTrend);
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[])
{
//---set arrays as series
ArraySetAsSeries(Trendline, true);
ArraySetAsSeries(price, true);
ArraySetAsSeries(smooth, true);
ArraySetAsSeries(detrender, true);
ArraySetAsSeries(i1, true);
ArraySetAsSeries(q1, true);
ArraySetAsSeries(i2, true);
ArraySetAsSeries(q2, true);
ArraySetAsSeries(re, true);
ArraySetAsSeries(im, true);
ArraySetAsSeries(period, true);
ArraySetAsSeries(smoothPeriod, true);
ArraySetAsSeries(iTrend, true);
ArraySetAsSeries(low, true);
ArraySetAsSeries(high, true);
int bars = rates_total - 1;
if(prev_calculated > 0)
bars = rates_total - prev_calculated;
for(int i = bars; i >= 0; i--)
{
//----Calculate price to be used
price[i] = ((high[i] + low[i]) * .5);
if(rates_total > 5)
{
smooth[i] = (4 * price[i] + 3 * price[i+1] + 2 * price[i+2] + price[i+3]) / 10;
detrender[i] = HilTransFilt(smooth[i], smooth[i+2], smooth[i+4], smooth[i+6], period[i+1]);
//---Compute inphase and quadrature components
q1[i] = HilTransFilt(detrender[i], detrender[i+2], detrender[i+4], detrender[i+6], period[i+1]);
i1[i] = detrender[i+3];
//---Advance the phase of i1 and q1 by 90 degrees
double jI = HilTransFilt(i1[i], i1[i+2], i1[i+4], i1[i+6], period[i+1]);
double jQ = HilTransFilt(q1[i], q1[i+2], q1[i+4], q1[i+6], period[i+1]);
//---Phasor addition for 3 bar averaging
i2[i] = i1[i] - jQ;
q2[i] = q1[i] + jI;
//--- smooth the i and q components
i2[i] = .2 * i2[i] + .8 * i2[i+1];
q2[i] = .2 * q2[i] + .8 * q2[i+1];
//---HomodyneDiscriminator
re[i] = i2[i] * i2[i+1] + q2[i] * q2[i+1];
im[i] = i2[i] * q2[i+1] - q2[i] * i2[i+1];
re[i] = .2 * re[i] + .8 * re[i+1];
im[i] = .2 * im[i] + .8 * im[i+1];
if(im[i] != 0 && re[i] != 0) period[i] = 360 / MathArctan(im[i] / re[i]);
if(period[i] > 1.5 * period[i+1]) period[i] = 1.5 * period[i+1];
if(period[i] < .67 * period[i+1]) period[i] = .67 * period[i+1];
if(period[i] < 6) period [i] = 6;
if(period[i] > 50) period[i] = 50;
period[i] = .2 * period[i] + .8 * period[i+1];
smoothPeriod[i] = .33 * period[i] + .67 * smoothPeriod[i+1];
//---compute Trendline as simple avg over the measure dominant cycle
iTrend[i] = 0;
int dcPeriod = CycPart * smoothPeriod[i] + .5;
for(int count = 0; count <= dcPeriod - 1; count++)
{
iTrend[i] = iTrend[i] + price[i+count];
}
if(dcPeriod > 0) iTrend[i] = iTrend[i] / dcPeriod;
Trendline[i] = (4 * iTrend[i] + 3 * iTrend[i+1] + 2 * iTrend[i+2] + iTrend[i+3]) / 10;

if(rates_total < 12) Trendline[i] = price[i];
} //end if <5
} //end for loop
//---return value of prev_calculated for next call
return(rates_total);
} //---end on_calculate
//+------------------------------------------+
//---functions
//+------------------------------------------+
//---Hilbert Transform Function
double HilTransFilt(double pVal0, double pVal2, double pVal4, double pVal6, double pPeriod)
{
return((.0962 * pVal0 + .5769 * pVal2 - .5769 * pVal4 - .0962 * pVal6) * (.075 * pPeriod + .54));
}

Any thoughts? I'd greatly appreciate it!!!