In this module we define the class
Ph_sel used to specify a
“selection” of a sub-set of photons/timestamps (i.e. all-photons,
Donor-excitation-period photons, etc…).
A photon selection is one of the base photon streams or a combination of them. Base photon streams are photon from the donor (or acceptor) emission channel detected during the donor (or acceptor) excitation period. For non-ALEX data there is only the donor excitation period.
The following table shows base photon streams for smFRET data (non-ALEX):
and for ALEX data:
|D-emission during D-excitation||
|A-emission during D-excitation||
|D-emission during A-excitation||
|A-emission during A-excitation||
Additionally, all the photons can be selected with
Ph_sel('all') (that is a
Ph_sel('all')select all photons.
Ph_sel(Dex='DAem')selects only donor and acceptor photons emitted during donor excitation. These are all the photons for non-ALEX data.
Ph_sel(Dex='Aem', Aex='Aem')selects all the photons detected from the acceptor-emission channel.
The documentation for the
Ph_sel class follows.
Class that describes a selection of photons.
This class takes two arguments
Aex. Valid values for the arguments are the strings ‘DAem’, ‘Dem’, ‘Aem’ or
None. These values select, respectively, donor+acceptor, donor-only, acceptor-only or no photons during an excitation period (
The class must be called with at least one keyword argument or using the string ‘all’ as the only argument. Calling
Ph_sel('all')is equivalent to
Ph_sel(Dex='DAem', Aex='DAem'). Not specifying a keyword argument is equivalent to setting it to None.