still cleaning up folder structures

Ausgleichsbecken/Ausgleichsbecken_functions.py

@@ -0,0 +1,30 @@
+import numpy as np 
+
+def get_h_halfstep(initial_height, influx, outflux, timestep, area):
+    h0      = initial_height
+    Q_in    = influx
+    Q_out   = outflux
+    dt      = timestep
+    A       = area
+
+    h_halfstep = h0+1/A*(Q_in-Q_out)*dt/2
+
+def get_p_halfstep(p0, p1):
+    p_halfstep = (p0+p1)/2
+
+def FODE_function(x, h, alpha, p, rho=1000., g=9.81):
+    f = x*abs(x)/h*alpha+g-p/(rho*h)
+    return f
+
+
+def e_RK_4(yn, h, dt, Q0, Q1, A0, A1, p0, p1):
+    alpha = (A1/A0-1)
+    h_hs = get_h_halfstep(h, Q0, Q1, dt, A0)
+    p_hs = get_p_halfstep(p0, p1)
+    Y1 = yn
+    Y2 = yn + dt/2*FODE_function(Y1, h, alpha, p0)
+    Y3 = yn + dt/2*FODE_function(Y2, h_hs, alpha, p_hs)
+    Y4 = yn + dt*FODE_function(Y3, h_hs, alpha, p_hs)
+    ynp1 = yn + dt/6*(FODE_function(Y1, h, alpha, p)+2*FODE_function(Y2, h_hs, alpha, p_hs)+ \
+        2*FODE_function(Y3, h_hs, alpha, p_hs)+ FODE_function(Y4, h, alpha, p))
+