Matplotlib scatter plot with different text at each data point

I am trying to make a scatter plot and annotate data points with different numbers from a list. So, for example, I want to plot y vs x and annotate with corresponding numbers from n.

y = [2.56422, 3.77284, 3.52623, 3.51468, 3.02199]
z = [0.15, 0.3, 0.45, 0.6, 0.75]
n = [58, 651, 393, 203, 123]
ax = fig.add_subplot(111)
ax1.scatter(z, y, fmt='o')

Any ideas?

Solution 1:

I'm not aware of any plotting method which takes arrays or lists but you could use annotate() while iterating over the values in n.

y = [2.56422, 3.77284, 3.52623, 3.51468, 3.02199]
z = [0.15, 0.3, 0.45, 0.6, 0.75]
n = [58, 651, 393, 203, 123]

fig, ax = plt.subplots()
ax.scatter(z, y)

for i, txt in enumerate(n):
    ax.annotate(txt, (z[i], y[i]))

There are a lot of formatting options for annotate(), see the matplotlib website:

Solution 2:

In case anyone is trying to apply the above solutions to a .scatter() instead of a .subplot(),

I tried running the following code

y = [2.56422, 3.77284, 3.52623, 3.51468, 3.02199]
z = [0.15, 0.3, 0.45, 0.6, 0.75]
n = [58, 651, 393, 203, 123]

fig, ax = plt.scatter(z, y)

for i, txt in enumerate(n):
    ax.annotate(txt, (z[i], y[i]))

But ran into errors stating "cannot unpack non-iterable PathCollection object", with the error specifically pointing at codeline fig, ax = plt.scatter(z, y)

I eventually solved the error using the following code

plt.scatter(z, y)

for i, txt in enumerate(n):
    plt.annotate(txt, (z[i], y[i]))

I didn't expect there to be a difference between .scatter() and .subplot() I should have known better.

Solution 3:

In versions earlier than matplotlib 2.0, ax.scatter is not necessary to plot text without markers. In version 2.0 you'll need ax.scatter to set the proper range and markers for text.

y = [2.56422, 3.77284, 3.52623, 3.51468, 3.02199]
z = [0.15, 0.3, 0.45, 0.6, 0.75]
n = [58, 651, 393, 203, 123]

fig, ax = plt.subplots()

for i, txt in enumerate(n):
    ax.annotate(txt, (z[i], y[i]))

And in this link you can find an example in 3d.