Add analysis of PR lifetime vs. num participants. (#3)

Author: rossbar

site/numpy_timeseries.md

@@ -369,9 +369,26 @@ fig.tight_layout();
 
 ### Number of PR participants
 
+% TODO: Similar analysis, but replace num participants with some metrics of
+% how "big" the PR is; num LOC changed, etc. 
+
 ```{code-cell} ipython3
 ---
 tags: [hide-input]
 ---
+# Get the lifetimes and number of participants for merged PRs
+lifetimes = np.array(
+    [isoparse(pr["mergedAt"]) - isoparse(pr["createdAt"]) for pr in merged_prs],
+    dtype="m8[h]",
+)
+num_participants = np.array([pr["participants"]["totalCount"] for pr in merged_prs])
 
+title = "Distribution of lifetimes for merged PRs based on the number of participants"
 
+p = figure(width=600, height=300, title=title)
+p.xgrid.grid_line_color = None
+p.xaxis.ticker = sorted(np.unique(num_participants))
+p.yaxis.axis_label = "PR lifetime (hours)"
+p.scatter(x=num_participants, y=lifetimes.astype(int), size=9, alpha=0.4)
+show(p)
+```