Added øvinger

Øvinger/Ø1/Oppgave4Python/Graftegning.py

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+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+"""
+Created on Fri Jan 18 22:30:00 2019
+
+@author: oyvind
+"""
+import math
+import matplotlib.pyplot as plt
+
+# Name for the saved graph
+filename = "4b"
+
+# Tau in microseconds
+tau = 10
+
+# Square wave freq in kHz
+sqWFreq = 5
+
+# How many taus you want
+periods = 40
+
+# The resolution of each tau
+resolution = 1000
+
+# Calculates the length of each squarewave in taus
+sqTime = (1/sqWFreq) * 10**3
+sqTau = sqTime / tau
+
+# Creats the  square wave
+# Default values are in the argument list
+def CreateSquareWave(amp=0.5, offset=0.5, symetry=0.5):
+    squareWave = []
+    # Only generates as many datapoints we need
+    while len(squareWave) < periods * resolution:
+        # First generate the first half
+        for r in range(int(resolution*sqTau * symetry)):
+            squareWave.append(amp + offset)
+        # Then the second
+        for r in range(int(resolution*sqTau * (1 - symetry))):
+            squareWave.append(offset - amp)
+    squareWave = squareWave[:(resolution*periods)]
+    return squareWave
+
+
+# Generate all the time-ticks
+def GenerateTime():
+    times = []
+    for t in range(periods * resolution):
+        times.append(t/resolution)
+    print(len(times))
+    return(times)
+    
+
+def CapVoltage(wave, times):
+    cP = wave[0] # Start voltage-supply
+    v0 = 0 # Start voltage
+    cT = 0 #Start time
+    volt = []
+    for p in range(len(wave)):
+        # If the voltage-supply changes, recalculate startvalues
+        if wave[p] != cP:
+            v0 = volt[-1] # New start voltage, uses the last voltage calculated
+            cP = wave[p] # Variable so the array is not accessed.
+            cT = times[p] # Offset time for each period
+        # Calculate the voltage over the CAPACITOR with the start values
+        volt.append(cP + (v0 - cP) * math.exp(-(times[p] - cT)))
+    return(volt)
+        
+        
+SquareWave = CreateSquareWave()
+time = GenerateTime()
+CapWave = CapVoltage(SquareWave, time)
+
+plt.figure(figsize=(15,5))
+plt.plot(time, SquareWave, time, CapWave)
+plt.xlabel("Time [τ]")
+plt.ylabel("Voltage [V]")
+plt.legend(["Supply voltage", "Capacitor voltage"], loc="lower right")
+plt.savefig(filename + ".png", dpi = 300)
+plt.show()
+
+