public RunStatus Run(IVariable <T> output, ref IVariable <T> gradient, params IVariable <T>[] input)
{
RunStatus s = Run(output, input);
if (s != RunStatus.Success)
{
gradient = null;
return(s);
}
var gc = new Gradient(Context, OutputValue);
var c = new Composer(_context);
GradientTensors = new Dictionary <DeviceTensor, DeviceTensor>();
for (int i = 0; i < InputTensors.Count; i++)
{
var t = InputTensors[i];
var grad = gc.ComputeWrt(t);
if (!grad.IsAllocated)
{
continue;
}
c.AddInputPlaceholder(InputTensors[i].Name, InputTensors[i].DimensionCount);
var gt = new DeviceTensor(t.Device, t.Shape, grad.Name);
c.AddOutputValue(gt);
c.AddUpdate(gt, grad);
GradientTensors.Add(t, gt);
}
var gf = c.BuildFunction();
var ginv = new Invoker <int>(_context, gf, InputTensors.ToArray(), GradientTensors.Values.ToArray());
var ginvc = ginv.Invoke();
if (!ginvc.IsAllocated)
{
gradient = null;
return(RunStatus.ErrorComputingGradient);
}
var gv = GradientTensors.First().Value.CreateView <T>(MemoryMapType.Retain);
if (!gv.CopyToAndFree(gradient.Span))
{
gv.Free();
gradient = null;
return(RunStatus.ErrorComputingGradient);
}
return(RunStatus.Success);
}
public void CanComputeGradient()
{
Device device = new Device(testContext);
string code = @"function (I) -> (O) {
O = I * I;
}";
Function f = new Function(testContext, code);
Assert.True(f.IsAllocated);
DeviceTensor i = new DeviceTensor(device, new Compiler.PlaidML.Shape(testContext, PlaidmlDatatype.PLAIDML_DATA_INT32, 6),
"I");
DeviceTensor o = new DeviceTensor(device, new Compiler.PlaidML.Shape(testContext, PlaidmlDatatype.PLAIDML_DATA_INT32, 6),
"O");
Int32[] input_data = { 0, 1, 3, 4, 5, 6 };
i.CreateView <Int32>(MemoryMapType.Discard).CopyFromAndFree(input_data);
var v = i.CreateView <Int32>(MemoryMapType.Retain);
Assert.Equal(3, v[2]);
Invoker <int> inv1 = new Invoker <int>(testContext, f, o, i);
Assert.True(inv1.IsAllocated);
Invocation <int> k = inv1.Invoke();
Assert.True(k.IsAllocated);
DeviceTensorView <Int32> R = o.CreateView <Int32>(MemoryMapType.Retain);
Assert.Equal(6, R.ElementCount);
Assert.Equal(9, R[2]);
var gradients = new Dictionary <DeviceTensor, Value>();
for (int n = 0; n < inv1.InputTensors.Count; n++)
{
Gradient gc = new Gradient(testContext, inv1.OutputValue);
if (!gc.IsAllocated)
{
continue;
}
Value grad = gc.ComputeWrt(inv1.InputTensors[n]);
if (!grad.IsAllocated)
{
continue;
}
gradients.Add(inv1.InputTensors[n], grad);
}
Composer c = new Composer(testContext);
foreach (DeviceTensor t in inv1.InputTensors)
{
Assert.True(c.AddInputPlaceholder(t.Name, t.DimensionCount));
}
List <DeviceTensor> gradTensors = new List <DeviceTensor>();
foreach (var g in gradients)
{
var gt = new DeviceTensor(g.Key.Device, g.Key.Shape, g.Value.Name);
c.AddOutputValue(gt);
c.AddUpdate(gt, g.Value);
gradTensors.Add(gt);
}
Function gf = c.BuildFunction();
Assert.True(gf.IsAllocated);
Invoker <int> ginv = new Invoker <int>(testContext, gf, inv1.InputTensors.ToArray(), gradTensors.ToArray());
Assert.True(ginv.IsAllocated);
var k2 = ginv.Invoke();
Assert.True(k2.IsAllocated);
DeviceTensorView <Int32> RG = gradTensors.First().CreateView <Int32>(MemoryMapType.Retain);
}