title: numpy array dimension mismatch error
body: <p>I am quite new to numpy and python in general. I am getting a dimension mismatch error when I try to append values even though I have made sure that both arrays have the same dimension. Also another question I have is why does numpy create a single dimensional array when reading in data from a tab delimited text file.</p>
  
  <pre><code>import numpy as np
  
  names = ["Angle", "RX_Power", "Frequency"]
  data = np.array([0,0,0],float)  #experimental
  
  data = np.genfromtxt("rx_power_mode 0.txt", dtype=float, delimiter='\t', names = names, usecols=[0,1,2], skip_header=1)
  
  freq_177 = np.zeros(shape=(data.shape))
  
  print(freq_177.shape)  #outputs(315,)
  
  for i in range(len(data)):
  
      if data[i][2] == 177:
          #np.concatenate(freq_177,data[i]) has same issue
          np.append(freq_177,data[i],0) 
  </code></pre>
  
  <p>The output I am getting is </p>
  
  <blockquote>
    <p>all the input arrays must have same number of dimensions</p>
  </blockquote>