Feature/coastal multi frequency

[sebastianrowan]

@HenryGeorgist two patterns here for implementing multi-frequency hazard. The coastal version here puts the frequency on the individual CoastalEvents and accesses the values through a Frequency() method. The version on the DepthEvent stores the frequencies as a slice in the MultiFrequencyDepth event.

Preference?

[HenryGeorgist]

Create an interface called "FrequencyEvent" that has the methods for Frequency and SetFreqeuncy.

then we can have the same behavoir on any event as long as a hazard provider provides it. i like the pattern

[HenryGeorgist]

hmm. this is interesting. have you thought through how that works with a hazard provider?

[sebastianrowan]

The hazard provider itself does not deal with the frequency. The hazard provider would provide a MultiFrequencyEvent which implements the HazardEvent interface (per your suggestion above it the MultiFrequencyEvent would implement the FrequencyEvent which would itself implement the HazardEvent).