Fsolve
in Scipy
seems to be the right candidate for this, I just need help passing equations dynamically. I appreciate any thoughts in advance.
By dynamic I mean number of equations differ from one run to another for example one situation i have :
alpha*x + (1-alpha)*x*y - y = 0
beta*x + (1- beta)*x*z - z = 0
A*x + B*y + C*z = D
and another situation i have:
alpha*x + (1-alpha)*x*y - y = 0
beta*x + (1- beta)*x*z - z = 0
gama*x + (1 -gama)*x*w - w =0
A*x + B*y + C*z + D*w = E
alpha
, beta
, A
, B
, C
, D
and E
are all constants. x
, y
, z
, w
are variables.
I haven't used Fsolve myself, but according to its documentation it takes a callable function. Something like this handles multiple functions with unknown number of variables. Bear in mind that the args must be ordered correctly here, but each function simply takes a list.
def f1(argList):
x = argList[0]
return x**2
def f2(argList):
x = argList[0]
y = argList[1]
return (x+y)**2
def f3(argList):
x = argList[0]
return x/3
fs = [f1,f2,f3]
args = [3,5]
for f in fs:
print f(args)
For Fsolve, you could try something like this (untested):
def func1(argList, constList):
x = argList[0]
y = argList[1]
alpha = constList[0]
return alpha*x + (1-alpha)*x*y - y
def func2(argList, constList):
x = argList[0]
y = argList[1]
z = argList[2]
beta = constList[1]
return beta*x + (1- beta)*x*z - z
def func3(argList, constList):
x = argList[0]
w = argList[1] ## or, if you want to pass the exact same list to each function, make w argList[4]
gamma = constList[2]
return gama*x + (1 -gama)*x*w - w
def func4(argList, constList):
return A*x + B*y + C*z + D*w -E ## note that I moved E to the left hand side
functions = []
functions.append((func1, argList1, constList1, args01))
# args here can be tailored to fit your function structure
# Just make sure to align it with the way you call your function:
# args = [argList, constLit]
# args0 can be null.
functions.append((func1, argList2, constList2, args02))
functions.append((func1, argList3, constList3, args03))
functions.append((func1, argList4, constList4, args04))
for func,argList, constList, args0 in functions: ## argList is the (Vector) variable you're solving for.
Fsolve(func = func, x0 = ..., args = constList, ...)