Constant EPG_TE_TOLERANCE_S 

pub const EPG_TE_TOLERANCE_S: f64 = 1e-4;

How far, in seconds, r2_epg’s echo times may be from TEₙ = n·ESP (each spacing from the first, and the first echo from the spacing): 0.1 ms, which covers the rounding of echo times in DICOM and BIDS sidecars.