data.aggregate.humidograph generates f(RH) curve fits for humidograph systems. There are several equations it can fit and several methods it can use to fit them, however for each invocation only one pair can be set. It assumes one hour RH scans.

data.aggregate.humidograph [--source=clean] 
                           [--method=default] [--equation=default] 
                           station [record] start end

The record field is ignored and only present so data.aggregate.humidograph can be used as an input source for data.get. All configured humidograph fits (one per output record) are generated by a call.

The time specifiers for the data to be retrieved. Start is inclusive while end is exclusive, so all data contained within the half open interval [start,end) will be returned. Any convertible time format is accepted.

The station identifier code. For example 'brw'. Case insensitive.

Averaging interval in seconds, defaulting to 3600. If the result is divisible by 60 seconds, the first bin has the minute field rounded down. If it is divisible by 3600 the hour field is also rounded, and the day field if it is day divisible. May also be “month” to average on month intervals.

Select the source archive to request data from, defaulting to clean.

Select the fit method to use, see below. Defaulting to LevenbergMarquardt.

Select the equation to fit, see below. Defaulting to TwoParameter.

http://cpan.uwinnipeg.ca/htdocs/PDL/PDL/Fit/LM.html http://pdl.perl.org/

http://search.cpan.org/~smueller/Algorithm-CurveFit-1.03/lib/Algorithm/CurveFit.pm

(1-RH/100)^(-gamma)

a*(1-RH/100)^(-gamma)

a + b * RH

Only for testing, does not give good fits on real data.

data.aggregate.humidograph sgp 2008:10 2008:11