dask inplace predict.

python-package/xgboost/core.py

@@ -210,7 +210,7 @@ def ctypes2numpy(cptr, length, dtype):
 def ctypes2cupy(cptr, length, dtype):
     """Convert a ctypes pointer array to a cupy array."""
     import cupy
-    mem = cupy.zeros((length.value, ), dtype=dtype, order='C')
+    mem = cupy.zeros(length.value, dtype=dtype, order='C')
     addr = ctypes.cast(cptr, ctypes.c_void_p).value
     # pylint: disable=c-extension-no-member,no-member
     cupy.cuda.runtime.memcpy(
@@ -487,6 +487,7 @@ def __init__(self, data, label=None, weight=None, base_margin=None,
         data, feature_names, feature_types = _convert_dataframes(
             data, feature_names, feature_types
         )
+        missing = np.nan if missing is None else missing
 
         if isinstance(data, (STRING_TYPES, os_PathLike)):
             handle = ctypes.c_void_p()
@@ -622,6 +623,7 @@ def _init_from_dt(self, data, nthread):
     def _init_from_array_interface_columns(self, df, missing, nthread):
         """Initialize DMatrix from columnar memory format."""
         interfaces_str = _cudf_array_interfaces(df)
+        nthread = nthread if nthread is not None else 1
         handle = ctypes.c_void_p()
         _check_call(
             _LIB.XGDMatrixCreateFromArrayInterfaceColumns(
@@ -1560,7 +1562,8 @@ def reshape_output(predt, rows):
         preds = ctypes.POINTER(ctypes.c_float)()
 
         # once caching is supported, we can pass id(data) as cache id.
-
+        if isinstance(data, DataFrame):
+            data = data.values
         if isinstance(data, np.ndarray):
             assert data.flags.c_contiguous
             arr = np.array(data.reshape(data.size), copy=False,

python-package/xgboost/dask.py

@@ -26,6 +26,7 @@
 from .compat import sparse, scipy_sparse
 from .compat import PANDAS_INSTALLED, DataFrame, Series, pandas_concat
 from .compat import CUDF_INSTALLED, CUDF_DataFrame, CUDF_Series, CUDF_concat
+from .compat import lazy_isinstance
 
 from .core import DMatrix, Booster, _expect
 from .training import train as worker_train
@@ -98,6 +99,9 @@ def concat(value):
         return pandas_concat(value, axis=0)
     if CUDF_INSTALLED and isinstance(value[0], (CUDF_DataFrame, CUDF_Series)):
         return CUDF_concat(value, axis=0)
+    if lazy_isinstance(value[0], 'cupy.core.core', 'ndarray'):
+        import cupy             # pylint: disable=import-error
+        return cupy.concatenate(value, axis=0)
     return dd.multi.concat(list(value), axis=0)
 
 
@@ -426,7 +430,6 @@ def dispatched_train(worker_addr):
                  local_param['n_jobs'] is not None and \
                  local_param['n_jobs'] != worker.nthreads:
                 msg = '`n_jobs` is specified.  ' + msg
-                print('local_param[n_jobs]', local_param['n_jobs'])
                 LOGGER.warning(msg)
             else:
                 local_param['nthread'] = worker.nthreads
@@ -502,11 +505,10 @@ def mapped_predict(partition, is_df):
         ).result()
         return predictions
     if isinstance(data, dd.DataFrame):
-        import dask
         predictions = client.submit(
             dd.map_partitions,
             mapped_predict, data, True,
-            meta=dask.dataframe.utils.make_meta({'prediction': 'f4'})
+            meta=dd.utils.make_meta({'prediction': 'f4'})
         ).result()
         return predictions.iloc[:, 0]
 
@@ -607,27 +609,45 @@ def inplace_predict(client, model, data,
         booster = model['booster']
     else:
         raise TypeError(_expect([Booster, dict], type(model)))
+    if not isinstance(data, (da.Array, dd.DataFrame)):
+        raise TypeError(_expect([da.Array, dd.DataFrame], type(data)))
 
-    def dispatched_predict(data):
+    def mapped_predict(data, is_df):
         worker = distributed_get_worker()
         booster.set_param({'nthread': worker.nthreads})
         prediction = booster.inplace_predict(
             data,
             iteration_range=iteration_range,
             predict_type=predict_type,
             missing=missing)
+        if is_df:
+            if lazy_isinstance(data, 'cudf.core.dataframe', 'DataFrame'):
+                import cudf
+                # There's an error with cudf saying `concat_cudf` got an
+                # expected argument `ignore_index`.  So the test here is just
+                # place holder.  So this is not working yet.
+                prediction = cudf.DataFrame({'prediction': prediction},
+                                            dtype=numpy.float32)
+            else:
+                # If it's  from pandas, the partition is a numpy array
+                prediction = DataFrame(prediction, columns=['prediction'],
+                                       dtype=numpy.float32)
         return prediction
 
-    msg = 'Only dask array is supported for inplace prediction'
-    assert isinstance(data, da.Array), msg
-
-    def map_blocks():
-        predictions = da.map_blocks(dispatched_predict, data, drop_axis=1)
+    if isinstance(data, da.Array):
+        predictions = client.submit(
+            da.map_blocks,
+            mapped_predict, data, False, drop_axis=1,
+            dtype=numpy.float32
+        ).result()
         return predictions
-
-    predictions = client.submit(map_blocks)
-    import dask
-    return dask.delayed(predictions).compute()
+    if isinstance(data, dd.DataFrame):
+        predictions = client.submit(
+            dd.map_partitions,
+            mapped_predict, data, True,
+            meta=dd.utils.make_meta({'prediction': 'f4'})
+        ).result()
+        return predictions.iloc[:, 0]
 
 
 def _evaluation_matrices(client, validation_set, sample_weights, missing):

tests/python-gpu/test_gpu_with_dask.py

@@ -2,6 +2,7 @@
 import pytest
 import numpy as np
 import unittest
+import xgboost
 
 if sys.platform.startswith("win"):
     pytest.skip("Skipping dask tests on Windows", allow_module_level=True)
@@ -29,6 +30,7 @@ class TestDistributedGPU(unittest.TestCase):
     def test_dask_dataframe(self):
         with LocalCUDACluster() as cluster:
             with Client(cluster) as client:
+                import cupy
                 X, y = generate_array()
 
                 X = dd.from_dask_array(X)
@@ -49,6 +51,42 @@ def test_dask_dataframe(self):
                 predictions = dxgb.predict(client, out, dtrain).compute()
                 assert isinstance(predictions, np.ndarray)
 
+                # There's an error with cudf saying `concat_cudf` got an
+                # expected argument `ignore_index`.  So the test here is just
+                # place holder.
+
+                # series_predictions = dxgb.inplace_predict(client, out, X)
+                # assert isinstance(series_predictions, dd.Series)
+
+                single_node = out['booster'].predict(
+                    xgboost.DMatrix(X.compute()))
+                cupy.testing.assert_allclose(single_node, predictions)
+
+    @pytest.mark.skipif(**tm.no_cupy())
+    def test_dask_array(self):
+        with LocalCUDACluster() as cluster:
+            with Client(cluster) as client:
+                import cupy
+                X, y = generate_array()
+
+                X = X.map_blocks(cupy.asarray)
+                y = y.map_blocks(cupy.asarray)
+                dtrain = dxgb.DaskDMatrix(client, X, y)
+                out = dxgb.train(client, {'tree_method': 'gpu_hist'},
+                                 dtrain=dtrain,
+                                 evals=[(dtrain, 'X')],
+                                 num_boost_round=2)
+                from_dmatrix = dxgb.predict(client, out, dtrain).compute()
+                inplace_predictions = dxgb.inplace_predict(
+                    client, out, X).compute()
+                single_node = out['booster'].predict(
+                    xgboost.DMatrix(X.compute()))
+                np.testing.assert_allclose(single_node, from_dmatrix)
+                cupy.testing.assert_allclose(
+                    cupy.array(single_node),
+                    inplace_predictions)
+
+
     @pytest.mark.skipif(**tm.no_dask())
     @pytest.mark.skipif(**tm.no_dask_cuda())
     @pytest.mark.mgpu

tests/python/test_with_dask.py

@@ -63,8 +63,14 @@ def test_from_dask_dataframe():
             from_df = prediction.compute()
 
             assert isinstance(prediction, dd.Series)
+            assert np.all(prediction.compute().values == from_dmatrix)
             assert np.all(from_dmatrix == from_df.to_numpy())
 
+            series_predictions = xgb.dask.inplace_predict(client, booster, X)
+            assert isinstance(series_predictions, dd.Series)
+            np.testing.assert_allclose(series_predictions.compute().values,
+                                       from_dmatrix)
+
 
 def test_from_dask_array():
     with LocalCluster(n_workers=5, threads_per_worker=5) as cluster: