45
Figure  5. Cu-Ag. Left-top panel: the classical Pearson and Kendall’s rank correlations for daily,
weekly and monthly time series. Right-top panel: the exponentially weighted Pearson correlation coefficient with α = 0.03 for daily, weekly and monthly data. Bottom panel: the comparison between classical Pearson and Kendall’s rank correlation coefficients and exponentially weighted Pearson correlation
coefficient for daily data for three different values of α parameter: 0.1, 0.03 and 0.01.
Figure  6. Cu-Au. Left-top panel: the classical Pearson and Kendall’s rank correlations for daily,
weekly and monthly time series. Right-top panel: the exponentially weighted Pearson correlation coefficient with α = 0.03 for daily, weekly and monthly data. Bottom panel: the comparison between classical Pearson and Kendall’s rank correlation coefficients and exponentially weighted Pearson correlation
coefficient for daily data for three different values of α parameter: 0.1, 0.03 and 0.01.
Cu -Ag
Pearson & Kendall
Pearson exp u = 0.03
- - Pearson daily
- - weekly
- - monthly
-0.5
- - Kendall daily
- - weekly
- - monthly
.1 l....':==~==:::;::'_~-~~-~
2011 2012 2013 2014 2015 2016 2017
Pearson & Kendall & Pearson exp - different a
- - Pearson
- -
Kendall
-0.5
- - Pearson exp o: = 0.1
- - Pearson exp o: = 0.03
- - Pearson exp a: = 0.01
·1 Ll====i:::::::::=~_L_-----'-------'--------L---L2011
2012
2013
2014
2015
201 6
2017
Cu -Au
Pearson & Kendall
Pearson exp a = 0.03
- - Pearson daily
- - weekly
-0.5
-0.5
- - monthly
- - Kendall daily
- - weekly
- - monthly
-1 L'::::===:::;::'_~-~~-~
2011 2012 2013 2014 2015 2016 2017
Pearson & Kendall & Pearson exp- different a
0.5
-0.5
- - Pearson exp a = 0.1
- - Pearson exp o = 0. 03
- - Pearson exp o = 0.0 1
_ , L-~----~-----L-----~----~----~-----L-2011
201 2
2013
2014
2015
2016
2017