writeln double precision

[Arun Chandrasekaran via Digitalmars-d-learn]

I've written a simple tool [1] to find the DET and CMC 
specifically for biometrics performance measurement.

When I generate the report, I expected to see high precision 
floating point numbers, but I see that writefln trims the 
precision to the last 6 digits after decimal point.

Am I doing the right thing here? Should I use a different format 
specifier?

[1] https://bitbucket.org/carun/biometrics-reports/src

Cheers,
Arun