Structures and DataFrames

Learning about structures. Appreciate any comments on the below

struct BASE

struct B1

struct B2

df = DataFrame(   type = [:B1,:B2], a=[1,1], b=[1,1], b1=[1,missing], b2=[missing,2]  )

value( x::B1 ) = x.base.a + x.b1 * 2
value( x::B2 ) = x.base.a + x.b2 * 3

Question 1
is there an easy way to put each row of df into the appropriate structure (B1, B2) ?
Iā€™d like to have a new column of df with the structures.
then apply the value function to this column.

Question 2
is it possible to avoid the x in the value function. Something like
value( ::B1... ) = base.a + b1 * 2

Question 3
I believe putting base::BASE into B1 and B2 like this is the best way to do inheritance in Julia (please correct me otherwise).

Question 4
Is it possible to include BASE in other structures but not require a prefix base. to access the a and b parameters. Assuming the B1 parameter set is unique e.g. a, b, b1

My actual example is FX Options. Iā€™d like to have a struct for the parameters common to all (Strike, Expiry, Settlement etc) and paste this into structs for the various types (Barrier, Digital, Asian etc).
Iā€™d prefer not to preface the base parameters with base.

julia> @rtransform df :s = begin
           base = BASE(:a, :b)
           :type == ^(:B1) ? B1(base, :b1) : B2(base, :b2)
2Ɨ6 DataFrame
 Row ā”‚ type    a      b      b1       b2       s                 
     ā”‚ Symbol  Int64  Int64  Int64?   Int64?   Any               
   1 ā”‚ B1          1      1        1  missing  B1(BASE(1, 1), 1)
   2 ā”‚ B2          1      1  missing        2  B2(BASE(1, 1), 2)


1 Like

thanks Peter. helpful as always:)