Use LazyOuterProduct to construct multi-dimensional quadratures. This change allwed to: - Replace the types Quadrature and InverseQuadrature by functions returning outer products of the 1D operators. - Avoid convoluted naming of types. DiagonalInnerProduct is now renamed to DiagonalQuadrature, similarly for InverseDiagonalInnerProduct.

include("sbpPlot.jl")

g = sbp.Grid.EquidistantGrid((100,75), (0.0, 0.0), (2pi, 3/2*pi))
op = sbp.readOperator("d2_4th.txt","h_4th.txt")
Laplace = sbp.Laplace(g, 1.0, op)

init(x,y) = sin(x) + cos(y)
v = sbp.Grid.evalOn(g,init)
u = zero(v)

sbp.apply!(Laplace,u,v)

#@show u
#@show u'*u

plotgridfunction(g,u)