Understanding drawdowns

Question

I am using Drawdowns function from PerformanceAnalytics package.

mydata:

                 One           
2009-07-31  0.000000000    
2009-08-31 -0.009114570   
2009-09-30  0.008233058   
2009-10-30  0.003175485   
2009-11-30  0.037916767   
2009-12-31  0.020002273   

PerfDrawdowns=Drawdowns(mydata)

                  One
2009-07-31  0.000000000      
2009-08-31 -0.009114570     
2009-09-30 -0.000956553      
2009-10-30  0.000000000      
2009-11-30  0.000000000      
2009-12-31  0.000000000    

I can't understand how the value -0.000956553 is computed... Anyone?

Best Regards

Answer 1

R> (1+-0.009114570)*(1+0.008233058)-1
[1] -0.0009565528