Need some help understanding some Amibroker code - Aussie Stock Forums

# Thread: Need some help understanding some Amibroker code

1. ## Need some help understanding some Amibroker code

Hi Guys,

I am a bit of a newbie in Amibroker.
I found this code which dates back 10 years BUT it gives me signals that are not too bad on the assets I track.

Could anyone help me make sense of what is happening inside please?
I tried to contact the programmer but the email bounced (well... ti was written 10y ago! )

// Trend Detection
// Graham Kavanagh 11 Jan 05
// I am using version 4.66.2, but believe this will work with last offical
//version.

function Rise( Pd, perd, Pl, perl )
{
MAL = LinearReg(Pl,perl);
R[0] = C[0]>(H[0]+L[0])/2;

for(i=1;i<BarCount;i++)
{
if( CondR[i] )
{
R[i] = 1;
}
else
{
if( CondF[i] )
{
R[i] = 0;
}
else
{
R[i] = R[i-1];
}
}
}
return R;
}

PrD = C;
PrL = (H+L)/2;
PrdD = PrdL = PrdM = Param("Prd",12,2,40,1);

permax = Max(prdd,prdl);

Rs = IIf( BarIndex()<permax, 0, Rise(PrD, PrdD, PrL, PrdL) );
Fs = IIf( BarIndex()<permax, 0, 1-Rs );

Confirm = MA(C,prdm);

function DirBar( dr, df )
{
B[0] = 0;

for(i=1;i<BarCount;i++)
{
if( dr[i-1] && df[i] )
{
B[i] = 1;
}
else
{
if( df[i-1] && dr[i] )
{
B[i] = 1;
}
else
{
B[i] = B[i-1] + 1;
}
}
}
return B;
}

Bs = DirBar( Rs, Fs );
Direction = ROC(Confirm,1) > 0 AND ROC(Confirm,5) > 0;
Downward = ROC(Confirm,1) < 0 AND ROC(Confirm,5) < 0;

Select = Rs AND Ref(Fs,-1);
Caution = Fs AND Ref(Rs,-1);

Change = IIf( Rs, H/ValueWhen(Fs,L)*100, L/ValueWhen(Rs,H)*100 );

Plot( C, "close", IIf( Rs, colorGreen, IIf( Fs, colorRed, colorBlack )),
styleBar);

PlotShapes( shapeSmallCircle* select, colorDarkGreen, 0, H, 5 );
PlotShapes( shapeSmallCircle* Caution, colorDarkRed, 0, L, -5 );

GraphXSpace=10;
_N( Title = "{{NAME}} - {{INTERVAL}} {{DATE}} Trend Plot - "+prdd+" Day" );

Filter = Select OR Caution;

// ---indicator end---
"Rise = " + Rs;
"Fall = " + Fs;
"Current Trend Bars = " + Bs;
"Trend Move = " + Change + " %";

2. ## Re: Need some help understanding some Amibroker code

Look at the blue/red Linear Regression Line and the candle colour changes. The fact is the price moves and the line bends after it. One of the better manipulations of price averages. This simple linear regression line code shows the simplicity.

Code:
```LinReg = LinearReg(C, Param("Lin Reg Period", 80, 1, 300, 1));
DirectionChange = IIf(LinReg > Ref(LinReg, -1), colorBlue, colorRed);

Plot(LinReg, "Lin. Reg.", DirectionChange, styleLine);```

Untitled.jpg

3. ## Re: Need some help understanding some Amibroker code

Hi Wysiwyg

thanks for taking time to respond!

your code seems very clear to me: a change in direction of the slope = change in direction of the trend.
Graham adds the ROC of the DEMA on 1 period at the beginning of the code.

I am not too sure about what these 2 blocks are for though.
Could you help me understand this? (sorry I cant buy you a beer... unless you swing by Singapore! )

Code:
```permax = Max(prdd,prdl);

Rs = IIf( BarIndex()<permax, 0, Rise(PrD, PrdD, PrL, PrdL) );
Fs = IIf( BarIndex()<permax, 0, 1-Rs );```
and

Code:
```Bs = DirBar( Rs, Fs );
Direction = ROC(Confirm,1) > 0 AND ROC(Confirm,5) > 0;
Downward = ROC(Confirm,1) < 0 AND ROC(Confirm,5) < 0;

Select = Rs AND Ref(Fs,-1);
Caution = Fs AND Ref(Rs,-1);

Change = IIf( Rs, H/ValueWhen(Fs,L)*100, L/ValueWhen(Rs,H)*100 );```

The rest seems more or less to make (some) sense

4. ## Re: Need some help understanding some Amibroker code

Originally Posted by choubix
Hi Wysiwyg

thanks for taking time to respond!

your code seems very clear to me: a change in direction of the slope = change in direction of the trend.
Graham adds the ROC of the DEMA on 1 period at the beginning of the code.

I am not too sure about what these 2 blocks are for though.
Could you help me understand this? (sorry I cant buy you a beer... unless you swing by Singapore! )
Sorry, I don't understand the loopy stuff that well but let's just say the same thing can be represented many ways. Functions are in the AFL library for greater education.