GCN example works

Author: yuehhua

examples/gcn.jl

@@ -1,6 +1,7 @@
 using GeometricFlux
 using Flux
 using Flux: onehotbatch, onecold, logitcrossentropy, throttle
+using Flux: @epochs
 using JLD2  # use v0.1.2
 using Statistics: mean
 using SparseArrays
@@ -40,6 +41,4 @@ train_data = [(train_X, train_y)]
 opt = ADAM(0.01)
 evalcb() = @show(accuracy(train_X, train_y))
 
-for i = 1:epochs
-    Flux.train!(loss, ps, train_data, opt, cb=throttle(evalcb, 10))
-end
+@epochs epochs Flux.train!(loss, ps, train_data, opt, cb=throttle(evalcb, 10))

src/operations/linalg.jl

@@ -120,6 +120,11 @@ Normalized Laplacian matrix of graph `g`.
 """
 function normalized_laplacian(adj::AbstractMatrix, T::DataType=eltype(adj); selfloop::Bool=false)
     selfloop && (adj += I)
+    _normalized_laplacian(adj, T)
+end
+
+# nograd can only used without keyword arguments
+Zygote.@nograd function _normalized_laplacian(adj::AbstractMatrix, T::DataType=eltype(adj))
     inv_sqrtD = inv_sqrt_degree_matrix(adj, T, dir=:both)
     T.(I - inv_sqrtD * adj * inv_sqrtD)
 end