allow P1 elements for p2_project!()

scripts/run_experiments.jl

@@ -112,6 +112,7 @@ end
 
 function p2_project!(p2, lambda)
     p2.space.element == DP0() || p2.space.element == DP1() ||
+        p2.space.element == P1() ||
         throw(ArgumentError("element unsupported"))
     p2d = reshape(p2.data, prod(p2.space.size), :) # no copy
     for i in axes(p2d, 2)