First draft of script

ecar.json

@@ -0,0 +1,28 @@
+{
+    "kwh_price_home": 0.2,
+    "kwh_price_commercial": 0.5,
+    "petrol_litre_price": 1.75,
+    "kilometers_per_year": 20000.0,
+    "years": 3,
+    "ecar": {
+	"label": "Nissan Leaf",
+        "price": 7600,
+        "taxes": 0,
+        "insurance": 354,
+        "kwh_per_kilometer": 0.16,
+        "maintenance": 200,
+	"charging_behaviour": {
+		"percent_free_charges": 80,
+		"percent_home_charges": 10,
+		"percent_commercial_charges": 10
+	}
+    },
+    "ccar": {
+	"label": "Suzuki Grand Vitara",
+        "price": 7000,
+        "taxes": 350,
+        "insurance": 362,
+        "litre_per_kilometer": 0.08,
+        "maintenance": 1000
+    }
+}

ecar.py

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+import matplotlib.pyplot as plt
+import numpy as np
+import json
+
+with open("ecar.json", "r") as rf:
+    settings = json.load(rf)
+
+kilometer_price = np.array( [settings["ecar"]["kwh_per_kilometer"] * settings["kwh_price_home"],
+                             settings["ccar"]["litre_per_kilometer"] * settings["petrol_litre_price"]])
+labels = [settings["ecar"]["label"], settings["ccar"]["label"]]
+price = np.array([settings["ecar"]["price"], settings["ccar"]["price"]])
+taxes = np.array([settings["ecar"]["taxes"], settings["ccar"]["taxes"]])
+insurance = np.array([settings["ecar"]["insurance"], settings["ccar"]["insurance"]])
+kilometer_price_ecar =      (settings["ecar"]["charging_behaviour"]["percent_home_charges"] * settings["kwh_price_home"]
+                        +    settings["ecar"]["charging_behaviour"]["percent_commercial_charges"] * settings["kwh_price_commercial"]) / 100.0
+driving = np.array([kilometer_price_ecar * settings["kilometers_per_year"], kilometer_price[1] * settings["kilometers_per_year"]])
+maintenance = np.array([settings["ecar"]["maintenance"], settings["ecar"]["maintenance"]])
+width = 0.3
+
+fig, ax = plt.subplots()
+ax.bar(labels, price, width, label = "Price", color = "gray")
+currenty = price
+y = 0
+
+for i in range(settings["years"]):
+#while currenty[0] > currenty[1]:
+    ax.bar(labels, taxes, width, bottom = currenty, label = "Taxes".format(y), color = "darkgreen")
+    currenty = currenty + taxes
+    ax.bar(labels, insurance, width, bottom = currenty, label = "Insurance".format(y), color = "royalblue")
+    currenty = currenty + insurance
+    ax.bar(labels, driving, width, bottom = currenty, label = "Driving".format(y), color = "midnightblue")
+    currenty = currenty + driving
+    ax.bar(labels, maintenance, width, bottom = currenty, label = "Maintenance".format(y), color = "lavender")
+    currenty = currenty + maintenance
+    y += 1
+ecar_top = currenty[0]
+#ax.plot(np.linspace(-0.2, 1.2, 10), [ecar_top]*10, "--", color = "firebrick", label = "Break even")
+ax.text(0.3, ecar_top * 0.95, "Break even: {} years, {} kilometers".format(y, y*settings["kilometers_per_year"]))
+ax.set_ylabel("CHF")
+ax.set_title("Comparision of economics electric vs. combustion car")
+ax.legend(["Price", "Taxes", "Insurance", "Driving", "Maintenance"])
+ax.grid(axis = "y")
+print("Break even after {} years and {} kilometers. {}, {}".format(y, y*settings["kilometers_per_year"], currenty[0], currenty[1]))
+plt.show()