use params instead of vars

src/backend/tensorflow/graph.jl

@@ -52,7 +52,10 @@ interp(ctx, c::Conv2D, x) =
 interp{T<:AArray}(ctx, p::Constant{Flux.Param{T}}) =
   haskey(ctx[:params], p.value) ?
      ctx[:params][p.value] :
-    (ctx[:params][p.value] = Variable(convertel(Float32, p.value.x)))
+    (ctx[:params][p.value] =
+       ctx[:variables] ?
+        Variable(Float32.(p.value.x)) :
+        placeholder(Float32))
 
 interp(ctx, p::Constant) = p.value
 
@@ -63,14 +66,15 @@ function interp(ctx, model, args...)
   interpret(ctx, g, interpv(ctx, args)...)
 end
 
-function tograph(model, args...)
+function tograph(model, args...; variables = false)
   ctx = Context(mux(iline, ilambda, imap, interp),
-                params = ObjectIdDict(), stacks = Dict())
+                params = ObjectIdDict(), stacks = Dict(), variables = variables)
   out = interp(ctx, model, map(constant, args)...)
   return ctx[:params], ctx[:stacks], out
 end
 
-TensorFlow.Tensor(m::Flux.Model, args...) = tograph(m, args...)[3]
+TensorFlow.Tensor(m::Flux.Model, args...) =
+  tograph(m, args...; variables = true)[3]
 
 RawTensor(data::Union{Batch,Seq}) = RawTensor(rawbatch(data))
 

src/backend/tensorflow/model.jl

@@ -22,7 +22,9 @@ dictt(xs, ys) = Dict(zip(collectt(xs), collectt(ys)))
 
 function (m::Exec)(args...)
   shapecheckt(m.input, args)
-  retuple(run(m.session, m.output, dictt(m.input, args)))
+  idict = dictt(m.input, args)
+  pdict = Dict(t => p.x for (p, t) in m.params)
+  retuple(run(m.session, m.output, merge(idict, pdict)))
 end
 
 mutable struct Model
@@ -34,7 +36,7 @@ end
 tf(model) = Model(model)
 
 function (m::Model)(args...)
-  args = mapt(x->convert.(Float32, x), args)
+  args = mapt(x->Float32.(x), args)
   isdefined(m, :graph) || (m.exec = makesession(m.model, args))
   @tferr m.exec.stacks m.exec(args...)
 end

test/backend/tensorflow.jl

@@ -27,7 +27,7 @@ end
   Y = Tensor(d, X)
   run(sess, global_variables_initializer())
 
-  @test run(sess, Y, Dict(X=>Float32.(xs))) ≈ d(xs)
+  @test run(sess, Y, Dict(X=>xs)) ≈ d(xs)
 end
 
 @testset "Stack Traces" begin