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Nested function problem - chipx - Oct-21-2020
Hi everyone, I created this nested function to solve this formula: sqrt(sin(x)*(cos(x)) but it doesn't work. Where am I wrong?
Thanks
chipx
this is the code:
Output:[output]import math
def f1(x):
a = math.sqrt(b)
def f2(x):
b = math.sin(x)*c
def f3(x):
c = math.cos(x)
return c
return b
return a
f1(5) RE: Nested function problem - deanhystad - Oct-21-2020
An embedded function still needs to be called. f1() never calls f2() and f2() never calls f3().
I think there is an indentation error. f3() never returns a value. f2() returns c, which is a variable inside f3(). f1() has two returns and will never get to "return a". The code should look more like this:
def f1(x):
def f2(x):
def f3(x):
return math.cos(x)
return f3(x) * math.sin(x)
return math.sqrt(f2(x))Code like this it should always be accompanied by a disclaimer."This code is written for the purposes of learning about embedded functions. Any use of this code would be a big mistake."
RE: Nested function problem - chipx - Oct-21-2020
(Oct-21-2020, 03:01 PM)deanhystad Wrote: An embedded function still needs to be called. f1() never calls f2() and f2() never calls f3().
I think there is an indentation error. f3() never returns a value. f2() returns c, which is a variable inside f3(). f1() has two returns and will never get to "return a". The code should look more like this:
def f1(x): def f2(x): def f3(x): return math.cos(x) return f3(x) * math.sin(x) return math.sqrt(f2(x))Code like this it should always be accompanied by a disclaimer.
"This code is written for the purposes of learning about embedded functions. Any use of this code would be a big mistake."
Thank you! but now what function do I call? to get a result.
RE: Nested function problem - jefsummers - Oct-21-2020
In the example, f1 calls f2 (in the return statement), and f2 calls f3. To get your answer, call f1(value)
RE: Nested function problem - chipx - Oct-21-2020
I imported math tried to call f1 but it gives me error:
Output:f1(5)RE: Nested function problem - deanhystad - Oct-21-2020
You will get that trying to take the square root of a negative number. sin(5) is negative, cos(5) is positive. f2(5) returns a negative number and f3(5) crashes when it tries to calculate the square root.
You should probably add some code to catch that problem and provide a more meaningful error message.
RE: Nested function problem - chipx - Oct-21-2020
I tried changing "cos" to "log10" and now it works.
Thank you!
Output:import math
def f1(x):
def f2(x):
def f3(x):
return math.log10(x)
return f3(x) * math.sin(x)
return math.sqrt(f2(x))
f1(3)0.25948286130604603RE: Nested function problem - deanhystad - Oct-21-2020
Until someone calls f1(4).
RE: Nested function problem - jefsummers - Oct-21-2020
Assuming this is actually a proof of concept, that is fine, but as @deanhystad points out, you really should have some checks to make sure you are not trying to get the square root of a negative number.