Added missing file

lib/Petzval/Merit.hs

@@ -0,0 +1,33 @@
+module Petzval.Merit where
+
+import Petzval.Calculations
+import Petzval.Types
+import Petzval.Trace
+import Petzval.Optics (Element, BakedIOR)
+import Petzval.System
+import Control.Lens
+import Data.Either
+import Linear
+
+import qualified Data.Map as Map
+
+type MeritPart a = [Element BakedIOR a] -> a
+
+data Calcuable a => TracedSystem a =
+  TracedSystem { system :: [Element BakedIOR a]
+               , field_angles :: [Double]
+               , wavelengths :: [Double]
+               , tracePoints :: [(Ray a, HitRecord a)]
+               }
+
+
+
+spotSize :: Calcuable a => a -> MeritPart a
+spotSize fa system = rmsSize
+                     . toListOf (each._pos._xy)
+                     . rights
+                     . map fst
+                     . map (raytrace system)
+                     . map (createRay Nothing ep fa)
+                     $ hexapolarPattern 10
+  where ep = entrancePupil system