Writing a function of two variables as a function in one variable

Question

Let's say I have the following function that is in 2 variables -

def banana(x,y):
    return exp(((-x**2/200))-0.5*(y+0.05*(x**2) - 100*0.05)**2)

and I would like to write it as -

def banana(x):

where x here is a vector of two variables; if that's possible?

Thanks for your help!

score 3 · Answer 1 · answered Jul 23 '17 at 19:08

Unpack the args in the beginning of your function:

def banana(args):
    x, y = args
    return exp(((-x**2/200))-0.5*(y+0.05*(x**2) - 100*0.05)**2)

or directly in the definition line:

def banana((x, y)):
    return exp(((-x**2/200))-0.5*(y+0.05*(x**2) - 100*0.05)**2)

score 2 · Answer 2 · answered Jul 23 '17 at 19:06

2

Yes, this is possible:

def _banana(x):
    return banana(*x)

answered Jul 23 '17 at 19:06

ForceBru

score 2 · Answer 3 · answered Jul 23 '17 at 19:07

2

You could write:

def banana(vector):
    x, y = vector
    return exp(((-x**2/200))-0.5*(y+0.05*(x**2) - 100*0.05)**2)

answered Jul 23 '17 at 19:07

Simeon Visser

score 1 · Accepted Answer · edited Jul 23 '17 at 19:09

1

may be something like

def banana(x):
    return exp(((-x[0]**2/200))-0.5*(x[1]+0.05*(x[0]**2) - 100*0.05)**2)

edited Jul 23 '17 at 19:09

Charles Duffy

answered Jul 23 '17 at 19:06

Entro

1

Backticks are only for code-formatting blocks of less than a line. Use four-space indents for multi-line blocks to get formatting as a contiguous block and color syntax rendering. – Charles Duffy Jul 23 '17 at 19:08
@CharlesDuffy, Thank you! – Entro Jul 23 '17 at 19:10
NP. (I took the liberty of fixing that up myself here; you can look at the edit history to see the difference). – Charles Duffy Jul 23 '17 at 19:10

score 0 · Answer 5 · answered Jul 23 '17 at 19:14

Yeah of course it's possible. You can use either a list or a tuple. Put you two variables into a list or a tuple

x = [5, 7] # A list
x = (5, 7) # A tuple

And you function should then be like that:

def banana(x):
    x, y = x # Unpacking
    return exp(((-x**2/200))-0.5*(y+0.05*(x**2) - 100*0.05)**2)

score -1 · Answer 6 · answered Jul 23 '17 at 19:06

-1

you can write with lists

def banana(x):
    return exp(((-x[0]**2/200))-0.5*(x[1]+0.05*(x[0]**2) - 100*0.05)**2)

answered Jul 23 '17 at 19:06

hicay

6 Answers6