display graphs for exchange rates

2021-01-24 21:56:14 +01:00
parent d0f3c18eec
commit 6cfffd99c5
8 changed files with 215 additions and 1 deletions
@@ -0,0 +1,96 @@
+from django.db import connection
+import datetime
+import matplotlib.pyplot as plt
+from io import StringIO
+from matplotlib.backends.backend_agg import FigureCanvasAgg
+from matplotlib.figure import Figure
+import matplotlib.ticker as plticker
+from django.http import HttpResponse
+
+class Graph:
+
+    def graph_days(self, Crypto, Fiat, DayDiff):
+
+        x = []
+        y = []
+
+        with connection.cursor() as cursor:
+            sql = """SELECT date(datetime_valid), rate FROM 
+                     (select date(datetime_valid) as day, max(datetime_valid) as last
+                        from exchangerate WHERE crypto_currency = %s AND fiat_currency = %s
+                        AND datetime_valid >= %s
+                        GROUP BY day
+                        ORDER BY datetime_valid DESC) AS a
+                     JOIN exchangerate AS b ON a.last = b.datetime_valid
+                     AND crypto_currency = %s AND fiat_currency = %s
+                     ORDER BY datetime_valid ASC"""
+            startDate = datetime.datetime.today().replace(hour=0, minute=0, second=0, microsecond=0) - datetime.timedelta(days=int(DayDiff))
+            cursor.execute(sql, [Crypto, Fiat, startDate, Crypto, Fiat])
+            rows = cursor.fetchall()
+            for row in rows:
+                x.append(datetime.datetime.strptime(row[0], '%Y-%m-%d'))
+                y.append(row[1])
+
+        if len(x) == 0:
+            raise Exception("no data for this time range in the database")
+
+        fig_size = plt.rcParams["figure.figsize"]
+        fig_size[0] = 5
+        fig_size[1] = 4
+        plt.rcParams["figure.figsize"] = fig_size
+
+        fig = Figure()
+        ax = fig.add_subplot(1, 1, 1)
+
+        ax.plot(x, y, color='green', linestyle='dashed', linewidth = 2,
+                 marker='o', markerfacecolor='blue', markersize=2)
+
+        loc = plticker.MultipleLocator(base=(len(x)/4.0))
+        ax.xaxis.set_major_locator(loc)
+
+        ax.set_xlabel("time")
+        ax.set_ylabel(Fiat)
+        ax.set_title(('%s in %s' % (Crypto, Fiat)))
+
+        response = HttpResponse(content_type = 'image/png')
+        canvas = FigureCanvasAgg(fig)
+        canvas.print_png(response)
+        return response
+
+    def graph_hours(self, Crypto, Fiat, HourDiff):
+
+        x = []
+        y = []
+
+        with connection.cursor() as cursor:
+            sql = """SELECT datetime_valid, rate FROM exchangerate
+                     WHERE crypto_currency = %s AND fiat_currency = %s
+                     AND datetime_valid >= %s
+                     ORDER BY datetime_valid ASC"""
+            startDate = datetime.datetime.today() - datetime.timedelta(hours=int(HourDiff))
+            cursor.execute(sql, [Crypto, Fiat, startDate])
+            rows = cursor.fetchall()
+            for row in rows:
+                x.append(row[0])
+                y.append(row[1])
+
+        if len(x) == 0:
+            raise Exception("no data for this time range in the database")
+
+        fig = Figure()
+        ax = fig.add_subplot(1, 1, 1)
+
+        ax.plot(x, y, color='green', linestyle='dashed', linewidth = 2,
+                 marker='o', markerfacecolor='blue', markersize=2)
+
+        loc = plticker.MultipleLocator(base=(len(x)/5.0))
+        ax.xaxis.set_major_locator(loc)
+
+        ax.set_xlabel("time")
+        ax.set_ylabel(Fiat)
+        ax.set_title(('%s in %s' % (Crypto, Fiat)))
+
+        response = HttpResponse(content_type = 'image/png')
+        canvas = FigureCanvasAgg(fig)
+        canvas.print_png(response)
+        return response