0

I'm working on line plotting a metric for a course module as well as each of its questions within a Jupyter Notebook using %matplotlib notebook. That part is no problem. A module has typically 20-35 questions, so it results in a lot of lines on a chart. Therefore, I am plotting the metric for each question in a low alpha and I want to change the alpha and display the question name when I hover over the line, then reverse those when no longer hovering over the line.

The thing is, I've tried every test version of interactivity from the matplotlib documentation on event handling, as well as those in this question. It seems like the mpl_connect event is never firing, whether I use click or hover.

Here's a test version with a reduced dataset using the solution to the question linked above. Am I missing something necessary to get events to fire?

def update_annot(ind):
    x,y = line.get_data()
    annot.xy = (x[ind["ind"][0]], y[ind["ind"][0]])
    text = "{}, {}".format(" ".join(list(map(str,ind["ind"]))), 
                           " ".join([names[n] for n in ind["ind"]]))
    annot.set_text(text)
    annot.get_bbox_patch().set_alpha(0.4)

def hover(event):
    vis = annot.get_visible()
    if event.inaxes == ax:
        cont, ind = line.contains(event)
        if cont:
            update_annot(ind)
            annot.set_visible(True)
            fig.canvas.draw_idle()
        else:
            if vis:
                annot.set_visible(False)
                fig.canvas.draw_idle()

module = 'bd2bc472-ee0d-466f-8557-788cc6de3018'
module_metrics[module] = {
    'q_count': 31,
    'sequence_pks': [0.5274546300604932,0.5262044653349001,0.5360993905297703,0.5292329279700655,0.5268691588785047,0.5319099014547161,0.5305164319248826,0.5268235294117647,0.573648805381582,0.5647933116581514,0.5669839795681448,0.5646591970121382,0.5663157894736842,0.5646976090014064,0.5659005628517824,0.5693634879925391,0.5728268468888371,0.5668834184858337,0.5687237026647967,0.5795640965549567,0.5877684407096172,0.585690904839841,0.5766899766899767,0.5971341320178529,0.6059972105997211,0.6055516678329834,0.6209865053513262,0.6203121360354065,0.6153666510976179,0.6236909471724459,0.6387654898293196],
    'q_pks': {
        '0da04f02-4aad-4ac8-91a5-214862b5c0d0': [0.6686046511627907,0.6282051282051282,0.76,0.6746987951807228,0.7092198581560284,0.71875,0.6585365853658537,0.7070063694267515,0.7171052631578947,0.7346938775510204,0.7737226277372263,0.7380952380952381,0.6774193548387096,0.7142857142857143,0.7,0.6962962962962963,0.723404255319149,0.6737588652482269,0.7232704402515723,0.7142857142857143,0.7164179104477612,0.7317073170731707,0.6333333333333333,0.75,0.7217391304347827,0.7017543859649122,0.7333333333333333,0.7641509433962265,0.6869565217391305,0.75,0.794392523364486],
        '10bd29aa-3a26-49e6-bc2c-50fd503d7ab5': [0.64375,0.6014492753623188,0.5968992248062015,0.5059523809523809,0.5637583892617449,0.5389221556886228,0.5576923076923077,0.51875,0.4931506849315068,0.5579710144927537,0.577922077922078,0.5467625899280576,0.5362318840579711,0.6095890410958904,0.5793103448275863,0.5159235668789809,0.6196319018404908,0.6143790849673203,0.5035971223021583,0.5897435897435898,0.5857142857142857,0.5851851851851851,0.6164383561643836,0.6054421768707483,0.5714285714285714,0.627906976744186,0.5826771653543307,0.6504065040650406,0.5864661654135338,0.6333333333333333,0.6851851851851852]
    }}

suptitle_size = 24
title_size = 18
tick_size = 12
axis_label_size = 15
legend_size = 14

fig, ax = plt.subplots(figsize=(15,8))
fig.suptitle('PK by Sequence Order', fontsize=suptitle_size)
module_name = 'Test'
q_count = module_metrics[module]['q_count']

y_ticks = [0.0,0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9,1.0]
x_ticks = np.array([x for x in range(0,q_count)])
x_labels = x_ticks + 1

# Plot it
ax.set_title(module_name, fontsize=title_size)
ax.set_xticks(x_ticks)
ax.set_yticks(y_ticks)
ax.set_xticklabels(x_labels, fontsize=tick_size)
ax.set_yticklabels(y_ticks, fontsize=tick_size)
ax.set_xlabel('Sequence', fontsize=axis_label_size)
ax.set_xlim(-0.5,q_count-0.5)
ax.set_ylim(0,1)
ax.grid(which='major',axis='y')

# Output module PK by sequence
ax.plot(module_metrics[module]['sequence_pks'])

# Output PK by sequence for each question
for qid in module_metrics[module]['q_pks']:
    ax.plot(module_metrics[module]['q_pks'][qid], alpha=0.15, label=qid)

annot = ax.annotate("", xy=(0,0), xytext=(-20,20),textcoords="offset points", bbox=dict(boxstyle="round", fc="w"), arrowprops=dict(arrowstyle="->"))
annot.set_visible(False)

mpl_id = fig.canvas.mpl_connect('motion_notify_event', hover)

Since there are dozens of modules, I created an ipywidgets dropdown to select the module, which then runs a function to output the chart. Nonetheless, whether running it hardcoded as here or from within the function, mpl_connect never seems to fire.

Here's what this one looks like when run test image

skustes
  • 97
  • 8
  • 2
    `line` and `names` is not defined in your code. Hence the event callback would create an error and stop executing. – ImportanceOfBeingErnest Apr 02 '20 at 15:26
  • Ah yes, good catch. Even with that, it doesn't work. I copied your line chart code snippet verbatim from [here](https://stackoverflow.com/a/47166787/1916187) and nothing happens. Is there a way to view the event and code errors? – skustes Apr 02 '20 at 15:33
  • 2
    Hard to tell. That linked code copied in a jupyter notebook and run with `%matplotlib notebook` works fine for me. – ImportanceOfBeingErnest Apr 02 '20 at 15:38
  • Interesting...it works in a fresh notebook. I'll keep digging. Thanks! – skustes Apr 02 '20 at 15:40
  • Putting %matplotlib notebook inside of the plotting cell solves the problem. I was declaring it at the top with my package imports where I typically declare %matpotlib inline. Thanks for your help. – skustes Apr 02 '20 at 16:19

0 Answers0