draw points using matplotlib.pyplot [[x1,y1],[x2,y2]]

Question

I want to draw graph using a list of (x,y) pairs instead of using two lists, one of X's and one of Y's. Something like this:

a = [[1,2],[3,3],[4,4],[5,2]] plt.plot(a, 'ro') 

Rather than:

plt.plot([1,3,4,5], [2,3,4,2]) 

Suggestions?

Answer 1

You can do something like this:

a=[[1,2],[3,3],[4,4],[5,2]] plt.plot(*zip(*a)) 

Unfortunately, you can no longer pass 'ro'. You must pass marker and line style values as keyword parameters:

a=[[1,2],[3,3],[4,4],[5,2]] plt.plot(*zip(*a), marker='o', color='r', ls='') 

The trick I used is unpacking argument lists.

Answer 2

If you are using numpy array you could extract by axis:

a = array([[1,2],[3,3],[4,4],[5,2]]) plot(a[:,0], a[:,1], 'ro') 

For lists or lists you'll need some helper, like:

a = [[1,2],[3,3],[4,4],[5,2]] plot(*sum(a, []), marker='o', color='r')