build a programm to test e-RK4-function - NOT WORKING YET

Ausgleichsbecken_class_file.py

@@ -0,0 +1,84 @@
+from Ausgleichsbecken import FODE_function, get_h_halfstep, get_p_halfstep
+class Ausgleichsbecken_class:
+# units
+    area_unit           = 'm^2'
+    area_outflux_unit   = 'm^2'
+    level_unit          = 'm'
+    volume_unit         = 'm^3'
+    flux_unit           = 'm^3/s'
+    time_unit           = 's'
+
+# init
+    def __init__(self,area,outflux_area,level_min,level_max,timestep = 1):
+        self.area           = area              # base area of the rectangular structure
+        self.area_outflux   = outflux_area      # area of the outlet towards the pipeline        
+        self.level_min      = level_min         # lowest  allowed water level    
+        self.level_max      = level_max         # highest allowed water level
+        self.timestep       = timestep          # timestep of the simulation    
+
+# setter
+    def set_volume(self):
+        self.volume = self.level*self.area 
+
+    def set_initial_level(self,initial_level):
+        self.level = initial_level
+        self.set_volume()
+
+    def set_influx(self,influx):
+        self.influx = influx
+
+    def set_outflux(self,outflux):
+        self.outflux = outflux
+
+# getter
+    def get_area(self):
+        print('The base area of the cuboid reservoir is', self.area, self.area_unit)
+
+    def get_outflux_area(self):
+        print('The outflux area from the cuboid reservoir to the pipeline is', \
+            self.area_outflux, self.area_outflux_unit)
+    
+    def get_level(self):
+        print('The current level in the reservoir is', self.level , self.level_unit)
+
+    def get_crit_levels(self):
+        print('The critical water levels in the reservoir are:  \n',\
+            '   Minimum:', self.level_min , self.level_unit , '\n',\
+            '   Maximum:', self.level_max , self.level_unit )
+
+    def get_volume(self):
+        print('The current water volume in the reservoir is', self.volume, self.volume_unit)
+
+    def get_timestep(self):
+        print('The timestep for the simulation is' , self.timestep, self.time_unit)
+
+    def get_influx(self):
+        print('The current influx is', self.influx, self.flux_unit)
+
+    def get_outflux(self):
+        print('The current outflux is', self.outflux, self.flux_unit)
+
+# methods
+    def update_level(self,timestep):
+        net_flux = self.influx-self.outflux
+        delta_V = net_flux*timestep
+        new_level = (self.volume+delta_V)/self.area
+        return new_level
+
+
+    def e_RK_4(self):
+        yn = self.outflux/self.area_outflux
+        h = self.level
+        dt = self.timestep
+        p = self.p0
+        p_hs = self.p0
+        alpha = (self.area/self.area_outflux-1)
+        h_hs = self.update_level(dt/2)
+        Y1 = yn
+        Y2 = yn + dt/2*FODE_function(Y1, h, alpha, self.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))
+
+        self.outflux = ynp1*self.area_outflux