1 files changed, 36 insertions, 0 deletions
diff --git a/python/fatcat_web/graphics.py b/python/fatcat_web/graphics.py
new file mode 100644
index 00000000..0e4b7c9d
--- /dev/null
+++ b/python/fatcat_web/graphics.py
@@ -0,0 +1,36 @@
+
+import pygal
+from pygal.style import CleanStyle
+
+def ia_coverage_histogram(rows):
+    """
+    Note: this returns a raw pygal chart; it does not render it to SVG/PNG
+    """
+
+    raw_years = [int(r[0]) for r in rows]
+    years = dict()
+    for y in range(min(raw_years), max(raw_years)+1):
+        years[int(y)] = dict(year=int(y), available=0, missing=0)
+    for r in rows:
+        if r[1]:
+            years[int(r[0])]['available'] = r[2]
+        else:
+            years[int(r[0])]['missing'] = r[2]
+
+    years = sorted(years.values(), key=lambda x: x['year'])
+
+    CleanStyle.colors = ("green", "purple")
+    label_count = len(years)
+    if len(years) > 20:
+        label_count = 10
+    chart = pygal.StackedBar(dynamic_print_values=True, style=CleanStyle,
+        width=1000, height=500, x_labels_major_count=label_count,
+        show_minor_x_labels=False)
+    #chart.title = "Perpetual Access Coverage"
+    chart.x_title = "Year"
+    #chart.y_title = "Releases"
+    chart.x_labels = [str(y['year']) for y in years]
+    chart.add('Available', [y['available'] for y in years])
+    chart.add('Missing', [y['missing'] for y in years])
+    return chart
+