diff --git a/src/Flux.jl b/src/Flux.jl
index 9a508002..f8db5553 100644
--- a/src/Flux.jl
+++ b/src/Flux.jl
@@ -23,7 +23,7 @@ include("core.jl")
 import .FluxCore: back!, update!, graph
 
 include("utils.jl")
-
+include("ops.jl")
 include("params.jl")
 
 include("compiler/code.jl")
diff --git a/src/backend/tensorflow/graph.jl b/src/backend/tensorflow/graph.jl
index b34e23a7..cf01de74 100644
--- a/src/backend/tensorflow/graph.jl
+++ b/src/backend/tensorflow/graph.jl
@@ -31,6 +31,15 @@ graph(::typeof(svd), x) = svd(x)
 graph(::typeof(size), x, dim) = TensorFlow.size(x,convert(Tensor{Int32}, dim))
 graph(::typeof(size), x) = TensorFlow.size(x)
 graph(::typeof(chol), args...) = TensorFlow.transpose(TensorFlow.cholesky(args...))
+graph(::typeof(reshape), x, dims) = TensorFlow.reshape(x,convert(Tensor{Int32},dims))
+graph(::typeof(Flux.tile), args...) = TensorFlow.tile(args...)
+graph(::typeof(fill), x, dims) = Ops.fill(convert(Tensor{Int32}, dims), Tensor(x))
+graph(::typeof(Flux.cast), args...) = TensorFlow.cast(args...)
+graph(::typeof(solve), A, b) = TensorFlow.matrix_solve(A, b)
+graph(::typeof(triangular_solve), A, b) = TensorFlow.matrix_triangular_solve(A, b; lower=false)
+graph(::typeof(randu), x) = Ops.random_uniform(convert(Tensor{Int32},x);dtype=Float32)
+graph(::typeof(randn), x) = TensorFlow.random_normal(convert(Tensor{Int32},x);dtype=Float32)
+graph(::typeof(Flux.expand_dims), x, dim) = TensorFlow.expand_dims(x,convert(Tensor{Int32},dim))
 
 for op in (*, .*, .+, .^, log, exp, ceil, floor, sqrt, abs, cos,
            sin, tan, atan, asin, acos, tanh, lgamma, erf, erfc, real, imag, conj,
diff --git a/src/backend/tensorflow/model.jl b/src/backend/tensorflow/model.jl
index 307f1961..512fbc15 100644
--- a/src/backend/tensorflow/model.jl
+++ b/src/backend/tensorflow/model.jl
@@ -1,4 +1,4 @@
-using Flux: mapt, collectt, shapecheckt
+using Flux: Param, mapt, collectt, shapecheckt
 
 struct Exec
   session ::Session
diff --git a/src/backend/tensorflow/tensorflow.jl b/src/backend/tensorflow/tensorflow.jl
index 7536bdbc..74c94012 100644
--- a/src/backend/tensorflow/tensorflow.jl
+++ b/src/backend/tensorflow/tensorflow.jl
@@ -1,7 +1,7 @@
 module TF
 
 using ..Flux, DataFlow, TensorFlow, Juno
-import Flux: accuracy, convertel, Param
+import Flux: accuracy, convertel
 
 export tf
 
diff --git a/src/ops.jl b/src/ops.jl
new file mode 100644
index 00000000..e9cb75b1
--- /dev/null
+++ b/src/ops.jl
@@ -0,0 +1,18 @@
+export reshape, tile, fill, cast, solve, triangular_solve, randu, randn,
+       expand_dims
+
+import Base: reshape, fill, randn
+
+reshape(x::AbstractArray, dims::AbstractArray) = reshape(x,tuple(dims...))
+tile(x::AbstractArray, mult::AbstractArray) = repeat(x,outer=tuple(mult...))
+fill{T}(x::T, dims::AbstractArray) = fill(x,tuple(dims...))
+cast{T}(x::AbstractArray, ::Type{T}) = convert(Array{T},x)
+solve(A::AbstractArray, b::AbstractArray) = A\b
+triangular_solve(A::AbstractArray, b::AbstractArray) = A\b
+randu(x::AbstractArray) = rand(tuple(x...))
+randn(x::AbstractArray) = randn(tuple(x...))
+
+function expand_dims(x,dim)
+    s = [size(x)...]
+    reshape(x,tuple(vcat(s[1:dim-1],1,s[dim:end])...))
+end
diff --git a/src/training.jl b/src/training.jl
index 62a34c46..3632eb82 100644
--- a/src/training.jl
+++ b/src/training.jl
@@ -25,18 +25,59 @@ macro cb(ex, t, f)
   end)
 end
 
+"""
+Returns a function that when invoked, will only be triggered at most once
+during `timeout` seconds. Normally, the throttled function will run
+as much as it can, without ever going more than once per `wait` duration;
+but if you'd like to disable the execution on the leading edge, pass
+`leading=false`. To enable execution on the trailing edge, ditto.
+"""
+function throttle(f, timeout; leading=true, trailing=false)
+  cooldown = true
+  later = nothing
+
+  function throttled(args...; kwargs...)
+    yield()
+
+    if cooldown
+      if leading
+        f(args...; kwargs...)
+      else
+        later = () -> f(args...; kwargs...)
+      end
+
+      cooldown = false
+      @schedule try
+        while (sleep(timeout); later != nothing)
+          later()
+          later = nothing
+        end
+      finally
+        cooldown = true
+      end
+    elseif trailing
+      later = () -> f(args...; kwargs...)
+    end
+
+    nothing
+  end
+end
+
 function train!(m, train; cb = [],
                 epoch = 1, η = 0.1, loss = mse)
+    callback = throttle(()->foreach(f -> f(), cb), 5)
+
     @progress for e in 1:epoch
       info("Epoch $e")
-      @cb for (x, y) in train
+      for (x, y) in train
         x, y = mapt(tobatch, (x, y))
         ŷ = m(x)
         any(isnan, ŷ) && error("NaN")
         Δ = back!(loss, 1, ŷ, y)
         back!(m, Δ, x)
         update!(m, η)
-      end 5 foreach(f -> f(), cb)
+        callback()
+      end
     end
     return m
 end
diff --git a/test/backend/tensorflow.jl b/test/backend/tensorflow.jl
index c647d41c..72ccd47f 100644
--- a/test/backend/tensorflow.jl
+++ b/test/backend/tensorflow.jl
@@ -47,6 +47,24 @@ end
   A = randn(6,5)
   A = A'*A
   @test tf(@net x -> chol(x))(A) ≈ chol(A)
+  A = randn(Float32,(6,3))
+  @test transpose(tf(@net (x,y) -> reshape(x,y))(transpose(A),[2,9])) ≈ reshape(A,(9,2)) # Note: TF is row major and julia is not
+  A = randn(Float32,(4,3,1))
+  @test tf(@net (x,y) -> Flux.tile(x,y))(A,[1,1,3]) ≈ repeat(A,outer=(1,1,3))
+  @test tf(@net (x,y) -> fill(x,y))(3.2,[3,2]) ≈ convert(Array{Float32},3.2*ones(3,2))
+  @test typeof(tf(@net x -> Flux.cast(x,Int32))(A)) == Array{Int32,3}
+  A = randn(Float32,(5,5))
+  b = randn(Float32,(5,1))
+  @test tf(@net (x,y) -> solve(x,y))(A,b) ≈ A\b
+  _,A,_ = lu(A)
+  @test tf(@net (x,y) -> triangular_solve(x,y))(A,b) ≈ A\b
+  @test size(tf(@net x -> randu(x))([2,3])) == (2,3)
+  @test size(tf(@net x -> randn(x))([2,3])) == (2,3)
+  m = tf(@net (x,y) -> Flux.expand_dims(x,y))
+  A = randn(Float32,(3,2))
+  @test m(A,1) ≈ Flux.expand_dims(A,1)
+  @test m(A,2) ≈ Flux.expand_dims(A,2)
+  @test m(A,3) ≈ Flux.expand_dims(A,3)
 end
 
 end
diff --git a/test/runtests.jl b/test/runtests.jl
index 655d924a..7128e13b 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -18,6 +18,7 @@ include("backend/common.jl")
 include("basic.jl")
 include("recurrent.jl")
 include("optimizer.jl")
+include("throttle.jl")
 
 @tfonly include("backend/tensorflow.jl")
 @mxonly include("backend/mxnet.jl")
diff --git a/test/throttle.jl b/test/throttle.jl
new file mode 100644
index 00000000..d3dcd925
--- /dev/null
+++ b/test/throttle.jl
@@ -0,0 +1,49 @@
+using Flux.throttle
+
+@testset "throttle" begin
+  @testset "default behaviour" begin
+    a = []
+    f = throttle(()->push!(a, now()), 1, leading=true, trailing=false)
+    f()
+    f()
+    f()
+    sleep(1.01)
+    @test length(a) == 1
+  end
+
+  @testset "leading behaviour" begin
+    a = []
+    f = throttle(()->push!(a, now()), 1, leading=true, trailing=false)
+    f()
+    @test length(a) == 1
+    f()
+    @test length(a) == 1
+    sleep(1.01)
+    f()
+    @test length(a) == 2
+  end
+
+  @testset "trailing behaviour" begin
+    a = []
+    f = throttle(()->push!(a, now()), 1, leading=false, trailing=true)
+    f()
+    @test length(a) == 0
+    f()
+    @test length(a) == 0
+    sleep(1.01)
+    @test length(a) == 1
+  end
+
+  @testset "arguments" begin
+    a = []
+    f = throttle((x)->push!(a, x), 1, leading=true, trailing=true)
+    f(1)
+    @test a == [1]
+    f(2)
+    @test a == [1]
+    f(3)
+    @test a == [1]
+    sleep(1.01)
+    @test a == [1, 3]
+  end
+end