There are a number of ways to create DataFrames. Given 1-dimensional column vectors, you can create a DataFrame by passing it a dict whose keys are column names and whose values are the 1-dimensional column vectors:
import numpy as np
import pandas as pd
x = np.random.randn(5)
y = np.sin(x)
df = pd.DataFrame({'x':x, 'y':y})
df.plot('x', 'y', kind='scatter')