Standardizing features by one specific feature
If this is a pandas DataFrame:

vel_mean = df.velocity.mean()
 vel_std = df.velocity.std()
 df = df.apply(lambda x: (x - vel_mean) / vel_std)


In case it is a numpy array:

data = (data - np.mean(data, axis=0)[0]) / np.std(data, axis=0)[0]