<SYSTEM_TASK:>
Given the following text problem statement, write Python code to implement the functionality described below in problem statement
<END_TASK>
<USER_TASK:>
Problem:
In pytorch, given the tensors a of shape (1X11) and b of shape (1X11), torch.stack((a,b),0) would give me a tensor of shape (2X11)
<ASSISTANT_TASK:>
Python Code:
import numpy as np
import pandas as pd
import torch
a, b = load_data()
ab = torch.cat((a, b), 0)
<END_TASK>