[FIXED] Multiply a Numpy array by a scalar to make every element an integer

Issue

I have the following Numpy array.

a = np.array([0.1, 0.9, 0.17, 0.47, 0.5])

How can I find a number such that, when multiplied by the array, turns every element into an integer?

For example, in this case, that number should be 100 because a times 100 would make every element an integer.

>>> a * 100
array([10., 90., 17., 47., 50.])

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I have tried taking 10 to the power of the longest decimal length. However, I need to find the smallest possible number (and it has to be greater than 0).

b = np.array([1.0, 0.5, 0.25, 0.75, 0.5])

As a result, that number should be 4 instead of 100 in this case.

>>> b * 4
array([4., 2., 1., 3., 2.])

Solution

Start with your strategy. Get the minimal power of 10 that makes your array integer. Then convert it to an integer and get the common divisor. The number you want is the power of 10 divided by the common divisor:

b = np.array([1.0, 0.5, 0.25, 0.75, 0.5])
d = np.gcd.reduce((b * 100).astype(int))

d is 25 here, and the number you want is 100/25 → 4.

Answered By - mozway