To calculate Pain ratio we divide the difference of the portfolio return
and the risk free rate by the Pain index
Usage
PainRatio(R, Rf = 0, ...)
Arguments
R
an xts, vector, matrix, data frame, timeSeries or zoo object of
asset returns
Rf
risk free rate, in same period as your returns
...
any other passthru parameters
Details
$$Pain ratio = \frac{r_P - r_F}{\sum^{n}_{i=1} \frac{\mid D'_i \mid}{n}}$$
where $r_P$ is the annualized portfolio return, $r_F$ is the risk free
rate, $n$ is the number of observations of the entire series, $D'_i$ is
the drawdown since previous peak in period i
References
Carl Bacon, Practical portfolio performance measurement
and attribution, second edition 2008 p.91