I’m new to python and also to numpy package. I was wondering what does this specific line really do.
a = numpy.vectorize(lambda x:1 - x^3)
I’ve searched about vectorize function but didn’t really get what it does.
I’m familiar with julia if there is any instance in julia that does what this line does I could understand it faster and better.
>Solution :
The keyword lambda on Python is used to declare an anonymous function. So the statement
a = lambda x: 1 - x**3
Is mathematically equivalent to:
a(x) = 1 - x^3
The vectorize function on NumPy is used to apply a function element-wise in an array. So, suppose you have an array x with elements [1,2,3], the result of a on x is:
[1-1^3,1-2^3,1-3^3]
I am not an expert in Julia, but I believe that the equivalent would be this:
a = function(x)
1 - x^3
end
And then, if you want to it use the same way Python would after the vectorize function, you would add a "." after the function name:
a.([1,2,3])