You can also overwrite eye Could you elaborate on the "90% of the users won't be aware of these internal details in their day-to-day coding" part? If we ignore the name for a while, why is `I` not what you want here? It is as efficient as it can possibly be.
On Sunday, August 28, 2016 at 3:39:20 PM UTC-4, Júlio Hoffimann wrote: > > Hi, > > I wanna revive a discussion around the return type of eye(). Currently > this function always returns a dense matrix, which is not desired > considering that the identity acts as a simple scalar in every single place > it is used. > > By exploiting the type system, one would ideally write algorithms with > eye() and get specialized function calls for a "ConstantMatrix" type saving > memory and unnecessary calculations. People have raised the existence of > this variable "I" defined in Base that acts as identity, but I still think > that this is not robust given that 1) I can easily overwrite "I" in my user > code and 2) 90% of the users won't be aware of these internal details in > their day-to-day coding. > > Also, can someone explain what is the use of eye(m,n) with m != n? If that > case is relevant for some applications, I would still expect to get a > SparseMatrix instead. > > Can you please share your opinions on this matter? > > -Júlio > > >
