private static (IntPtr[], IntPtr[]) ParseHead(NDArrayList heads, NDArrayList head_grads)
{
IntPtr[] headHandles = null;
IntPtr[] headGradHandles = null;
headHandles = MxUtil.GetNDArrayHandles(heads);
if (head_grads == null)
{
headGradHandles = new IntPtr[heads.Length];
for (var i = 0; i < headHandles.Length; i++)
{
headGradHandles[i] = IntPtr.Zero;
}
}
else
{
if (heads.Length != head_grads.Length)
{
throw new ArgumentException("heads and head_grads must be lists of the same length");
}
headGradHandles = MxUtil.GetNDArrayHandles(head_grads);
}
return(headHandles, headGradHandles);
}
public static void MarkVariables(NDArrayList variables, NDArrayList gradients,
OpGradReq grad_reqs = OpGradReq.Write)
{
var gradReqs = new int[variables.Length];
for (var i = 0; i < gradReqs.Length; i++)
{
gradReqs[i] = (int)OpGradReq.Write;
}
NativeMethods.MXAutogradMarkVariables(variables.Length, MxUtil.GetNDArrayHandles(variables), gradReqs,
MxUtil.GetNDArrayHandles(gradients));
}
public NDArrayList Call(NDArrayList args)
{
NativeMethods.MXInvokeCachedOpEx(handle, args.Length, MxUtil.GetNDArrayHandles(args), out var num_outputs,
out var outputs, out var out_stypes);
var result = new NDArrayList();
for (var i = 0; i < num_outputs; i++)
{
result.Add(new NDArray(outputs[i]).ToSType((StorageStype)out_stypes[i]));
}
return(result.ToArray());
}
public static NDArrayList Grad(NDArrayList heads, NDArrayList variables, NDArrayList head_grads = null,
bool retain_graph = false, bool create_graph = true, bool train_mode = true)
{
var(head_handles, head_grads_handles) = ParseHead(heads, head_grads);
//var grad_handles = new IntPtr[head_handles.Length];
//var grad_stypes = new int[head_handles.Length];
NativeMethods.MXAutogradBackwardEx(head_handles.Length, head_handles, head_grads_handles, variables.Length,
MxUtil.GetNDArrayHandles(variables), Convert.ToInt32(retain_graph),
Convert.ToInt32(create_graph), Convert.ToInt32(train_mode), out var grad_handles, out var grad_stypes);
var result = new NDArrayList();
foreach (var item in grad_handles)
{
result.Add(new NDArray(item));
}
return(result.ToArray());
}
public CachedOp(Symbol sym, NDArrayDict flags)
{
handle = IntPtr.Zero;
NativeMethods.MXCreateCachedOpEx(sym.GetHandle(), flags.Count, flags.Keys.ToArray(),
MxUtil.GetNDArrayHandles(flags.Values.ToArray()), out handle);
}