fc2d_layer: add example for 2d mlp

Author: OneAdder

example/simple_2d_mlp.f90

@@ -0,0 +1,35 @@
+program simple
+  use nf, only: dense, fc2d, flatten, linear2d, input, network, sgd, relu, tanhf
+  implicit none
+  type(network) :: net
+  real, allocatable :: x(:, :), y(:)
+  integer, parameter :: num_iterations = 25
+  integer :: n
+
+  print '("Simple")'
+  print '(60("="))'
+
+  net = network([ &
+    input(4, 5), &
+    fc2d(3, 2, activation=relu()), &
+    flatten(), &
+    dense(4, activation=tanhf()) &
+  ])
+
+  call net % print_info()
+
+  allocate(x(4, 5))
+  call random_number(x)
+  y = [0.123456, 0.246802, 0.9, 0.001]
+
+  do n = 0, num_iterations
+
+    call net % forward(x)
+    call net % backward(y)
+    call net % update(optimizer=sgd(learning_rate=0.05))
+
+    if (mod(n, 5) == 0) print *, n, net % predict(x)
+
+  end do
+
+end program simple