#!/usr/bin/env python # -*- coding: utf-8 -*- # Copyright 1999-2020 Alibaba Group Holding Ltd. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. from ..datasource import tensor as astensor from .concatenate import concatenate [docs]def column_stack(tup): """ Stack 1-D tensors as columns into a 2-D tensor. Take a sequence of 1-D tensors and stack them as columns to make a single 2-D tensor. 2-D tensors are stacked as-is, just like with `hstack`. 1-D tensors are turned into 2-D columns first. Parameters ---------- tup : sequence of 1-D or 2-D tensors. Tensors to stack. All of them must have the same first dimension. Returns ------- stacked : 2-D tensor The tensor formed by stacking the given tensors. See Also -------- stack, hstack, vstack, concatenate Examples -------- >>> import mars.tensor as mt >>> a = mt.array((1,2,3)) >>> b = mt.array((2,3,4)) >>> mt.column_stack((a,b)).execute() array([[1, 2], [2, 3], [3, 4]]) """ from ..datasource import array arrays = [] for a in tup: a = astensor(a) if a.ndim < 2: a = array(a, ndmin=2).T arrays.append(a) return concatenate(arrays, 1)