DEFUN_DLD ( sinewave_indicator, args, nargout )
{
octave_value_list retval_list ;
int nargin = args.length () ;
int vec_length = args(0).length () ;
// check the input argument
if ( nargin != 1 )
{
error ("Invalid argument. Input is a single price vector.") ;
return retval_list ;
}
if ( vec_length < 50 )
{
error ("Invalid argument. Input is a single price vector.") ;
return retval_list ;
}
if ( error_state )
{
error ("Invalid argument. Input is a single price vector.") ;
return retval_list ;
}
// end of input checking
// inputs
ColumnVector price = args(0).column_vector_value () ;
// outputs
ColumnVector sinewave( vec_length ) ;
ColumnVector sinewave_lead_1( vec_length ) ;
ColumnVector smoothperiod_out( vec_length ) ;
ColumnVector dcphase_vec( vec_length ) ;
ColumnVector sumperiod( vec_length ) ;
ColumnVector sum_period( vec_length ) ;
ColumnVector deltaphase( vec_length ) ;
// Declarations for calculations of period, phase & sine wave measurements
ColumnVector smooth( vec_length ) ;
ColumnVector period( vec_length ) ;
ColumnVector smoothperiod( vec_length ) ;
ColumnVector detrender( vec_length ) ;
ColumnVector Q1( vec_length ) ;
ColumnVector I1( vec_length ) ;
ColumnVector jI( vec_length ) ;
ColumnVector jQ( vec_length ) ;
ColumnVector I2( vec_length ) ;
ColumnVector Q2( vec_length ) ;
ColumnVector sI2( vec_length ) ;
ColumnVector sQ2( vec_length ) ;
ColumnVector Re( vec_length ) ;
ColumnVector Im( vec_length ) ;
ColumnVector sRe( vec_length ) ;
ColumnVector sIm( vec_length ) ;
int dcperiod ;
double realpart ;
double imagpart ;
double dcphase ;
double sum_deltaphase ;
int count ;
// unrolled loop to fill the first 5 elements of above calculation vectors ( unrolled for speed optimisation )
sinewave(0) = 0.0 ; sinewave(1) = 0.0 ; sinewave(2) = 0.0 ; sinewave(3) = 0.0 ; sinewave(4) = 0.0 ;
sinewave_lead_1(0) = 0.0 ; sinewave_lead_1(1) = 0.0 ; sinewave_lead_1(2) = 0.0 ; sinewave_lead_1(3) = 0.0 ; sinewave_lead_1(4) = 0.0 ;
smoothperiod_out(0) = 0.0 ; smoothperiod_out(1) = 0.0 ; smoothperiod_out(2) = 0.0 ; smoothperiod_out(3) = 0.0 ; smoothperiod_out(4) = 0.0 ;
dcphase_vec(0) = 0.0 ; dcphase_vec(1) = 0.0 ; dcphase_vec(2) = 0.0 ; dcphase_vec(3) = 0.0 ; dcphase_vec(4) = 0.0 ;
smooth(0) = 0.0 ; smooth(1) = 0.0 ; smooth(2) = 0.0 ; smooth(3) = 0.0 ; smooth(4) = 0.0 ;
period(0) = 0.0 ; period(1) = 0.0 ; period(2) = 0.0 ; period(3) = 0.0 ; period(4) = 0.0 ;
smoothperiod(0) = 0.0 ; smoothperiod(1) = 0.0 ; smoothperiod(2) = 0.0 ; smoothperiod(3) = 0.0 ; smoothperiod(4) = 0.0 ;
detrender(0) = 0.0 ; detrender(1) = 0.0 ; detrender(2) = 0.0 ; detrender(3) = 0.0 ; detrender(4) = 0.0 ;
Q1(0) = 0.0 ; Q1(1) = 0.0 ; Q1(2) = 0.0 ; Q1(3) = 0.0 ; Q1(4) = 0.0 ;
I1(0) = 0.0 ; I1(1) = 0.0 ; I1(2) = 0.0 ; I1(3) = 0.0 ; I1(4) = 0.0 ;
jI(0) = 0.0 ; jI(1) = 0.0 ; jI(2) = 0.0 ; jI(3) = 0.0 ; jI(4) = 0.0 ;
jQ(0) = 0.0 ; jQ(1) = 0.0 ; jQ(2) = 0.0 ; jQ(3) = 0.0 ; jQ(4) = 0.0 ;
I2(0) = 0.0 ; I2(1) = 0.0 ; I2(2) = 0.0 ; I2(3) = 0.0 ; I2(4) = 0.0 ;
Q2(0) = 0.0 ; Q2(1) = 0.0 ; Q2(2) = 0.0 ; Q2(3) = 0.0 ; Q2(4) = 0.0 ;
sI2(0) = 0.0 ; sI2(1) = 0.0 ; sI2(2) = 0.0 ; sI2(3) = 0.0 ; sI2(4) = 0.0 ;
sQ2(0) = 0.0 ; sQ2(1) = 0.0 ; sQ2(2) = 0.0 ; sQ2(3) = 0.0 ; sQ2(4) = 0.0 ;
Re(0) = 0.0 ; Re(1) = 0.0 ; Re(2) = 0.0 ; Re(3) = 0.0 ; Re(4) = 0.0 ;
Im(0) = 0.0 ; Im(1) = 0.0 ; Im(2) = 0.0 ; Im(3) = 0.0 ; Im(4) = 0.0 ;
sRe(0) = 0.0 ; sRe(1) = 0.0 ; sRe(2) = 0.0 ; sRe(3) = 0.0 ; sRe(4) = 0.0 ;
sIm(0) = 0.0 ; sIm(1) = 0.0 ; sIm(2) = 0.0 ; sIm(3) = 0.0 ; sIm(4) = 0.0 ;
for ( octave_idx_type ii (5) ; ii < vec_length ; ii++ ) // Start the main loop
{
// smooth the price for hilbert calculations
smooth(ii) = (4.0 * price(ii) + 3.0 * price(ii-1) + 2.0 * price(ii-2) + price(ii-3) ) / 10.0 ;
// Detrend the input
detrender(ii) = (0.0962 * smooth(ii) + 0.5769 * smooth(ii-2) - 0.5769 * smooth(ii-4) - 0.0962 * smooth(ii-6)) * (0.075 * period(ii-1) + 0.54) ;
// Compute InPhase and Quadrature components
Q1(ii) = (0.0962 * detrender(ii) + 0.5769 * detrender(ii-2) - 0.5769 * detrender(ii-4) - 0.0962 * detrender(ii-6)) * (0.075 * period(ii-1) + 0.54) ;
I1(ii) = detrender(ii-3) ;
// Advance the phase of I1 and Q1 by 90 degrees
jI(ii) = (0.0962 * I1(ii) + 0.5769 * I1(ii-2) - 0.5769 * I1(ii-4) - 0.0962 * I1(ii-6)) * (0.075 * period(ii-1) + 0.54) ;
jQ(ii) = (0.0962 * Q1(ii) + 0.5769 * Q1(ii-2) - 0.5769 * Q1(ii-4) - 0.0962 * Q1(ii-6)) * (0.075 * period(ii-1) + 0.54) ;
// Phasor addition for 3 bar averaging
I2(ii) = I1(ii) - jQ(ii) ;
Q2(ii) = Q1(ii) + jI(ii) ;
// Smooth the I and Q components before applying the discriminator
sI2(ii) = 0.2 * I2(ii) + 0.8 * sI2(ii-1) ;
sQ2(ii) = 0.2 * Q2(ii) + 0.8 * sQ2(ii-1) ;
// Homodyne Discriminator
Re(ii) = sI2(ii) * sI2(ii-1) + sQ2(ii) * sQ2(ii-1) ;
Im(ii) = sI2(ii) * sQ2(ii-1) - sQ2(ii) * sI2(ii-1) ;
sRe(ii) = 0.2 * Re(ii) + 0.8 * sRe(ii-1) ;
sIm(ii) = 0.2 * Im(ii) + 0.8 * sIm(ii-1) ;
if ( (sIm(ii) > 0.0 || sIm(ii) < 0.0) && (sRe(ii) > 0.0 || sRe(ii) < 0.0) )
{
period(ii) = 360.0 / ( ((atan(sIm(ii) / sRe(ii))) * 180.0) / PI ) ;
}
else
{
period(ii) = period(ii-1) ;
}
if ( period(ii) > 1.5 * period(ii-1) )
{
period(ii) = 1.5 * period(ii-1) ;
}
if ( period(ii) < 0.67 * period(ii-1) )
{
period(ii) = 0.67 * period(ii-1) ;
}
if ( period(ii) < 6.0 )
{
period(ii) = 6.0 ;
}
if ( period(ii) > 50.0 )
{
period(ii) = 50.0 ;
}
period(ii) = 0.2 * period(ii) + 0.8 * period(ii-1) ;
smoothperiod(ii) = 0.33 * period(ii) + 0.67 * smoothperiod(ii-1) ;
// Compute Dominant Cycle
dcperiod = int ( smoothperiod(ii) + 0.5 ) ;
realpart = 0.0 ;
imagpart = 0.0 ;
dcphase = 0.0 ;
for ( octave_idx_type jj (0) ; jj <= ( dcperiod - 1 ) ; jj++ )
{
realpart += sin( PI/180.0 * 360.0 * jj / dcperiod ) * ( smooth(ii-jj) ) ;
imagpart += cos( PI/180.0 * 360.0 * jj / dcperiod ) * ( smooth(ii-jj) ) ;
}
if ( fabs( imagpart ) > 0.0 )
{
dcphase = atan( realpart / imagpart ) * 180.0 / PI ;
}
else if ( fabs( imagpart ) < 0.001 )
{
if ( realpart < 0.0 )
{
dcphase -= 90.0 ;
}
else if ( realpart > 0.0 )
{
dcphase += 90.0 ;
}
}
dcphase += 90.0 ;
// Compensate for one bar lag of the 4 bar weighted moving average
dcphase += 360.0 / smoothperiod(ii) ;
if ( imagpart < 0.0 )
dcphase += 180.0 ;
if ( dcphase > 315.0 )
dcphase -= 360.0 ;
// phase output
dcphase_vec(ii) = dcphase ;
//Now compute a differential phase, resolve phase wraparound, and limit delta phase errors
deltaphase(ii) = dcphase_vec(ii) - dcphase_vec(ii-1) ;
if ( dcphase_vec(ii-1) > 270.0 && dcphase_vec(ii) < 90.0 )
{
deltaphase(ii) = 360.0 - dcphase_vec(ii-1) + dcphase_vec(ii) ;
}
if ( deltaphase(ii) < 1.0 )
{
deltaphase(ii) = 1.0 ;
}
if ( deltaphase(ii) > 60.0 )
{
deltaphase(ii) = 60.0 ;
}
// Sum Deltaphases to reach 360 degrees. The sum is the instantaneous period.
sum_period(ii) = 0.0 ;
sum_deltaphase = 0.0 ;
count = 0 ;
while ( sum_deltaphase < 360.0 )
{
sum_deltaphase += deltaphase(ii-count) ;
count ++ ;
sum_period(ii) = count ;
}
// Resolve Instantaneous Period errors and smooth
if ( sum_period(ii) == 0.0 )
{
sum_period(ii) = sum_period(ii-1) ;
}
sumperiod(ii) = 0.25 * sum_period(ii) + 0.75 * sum_period(ii-1) ;
// sinewave output
sinewave(ii) = sin( dcphase * PI / 180.0 ) ;
// one bar leading function
sinewave_lead_1(ii) = sin( ( dcphase + 360.0 / smoothperiod(ii) ) * PI / 180.0 ) ;
// period output
smoothperiod_out(ii) = floor ( smoothperiod(ii) + 0.5 ) ;
} // end of main ii loop
retval_list(3) = dcphase_vec ;
retval_list(2) = smoothperiod_out ;
retval_list(1) = sinewave_lead_1 ;
retval_list(0) = sinewave ;
return retval_list ;
} // end of function
This is a straightforward conversion of the code available from here. A nice intro to how it can be used is here and Ehler's own website can be found here.
"Trading is statistics and time series analysis." This blog details my progress in developing a systematic trading system for use on the futures and forex markets, with discussion of the various indicators and other inputs used in the creation of the system. Also discussed are some of the issues/problems encountered during this development process. Within the blog posts there are links to other web pages that are/have been useful to me.
Monday, 21 December 2015
John Ehler's Sinewave Indicator Code
A reader recently inquired about my use of this indicator and so below I provide my Octave C++ .oct version that I have been using for the past few years.
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