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Basic mathematical functions for Numpy Arrays-Part 1

In this post we are going to have a look at some of the mathematical functions which can be used with numpy arrays.Also there will be details regarding the syntax of these functions.There will be many mathematical functions to be used but this post will cover only the widely used functions.
Hello All,

This post is the first post of the tri series articles on the Mathematical functions for Numpy Arrays.We are going to take a look at some mathematical functions which can be used with the arrays. Also these functions will be very helpful while doing some common mathematical operations.

Following is the list of functions which we are going to take a look at:
1. Sum
2. Prod
3. Min
4. Argmin

Let us start going through the functions one at a time .

1.sum

Sum function is used for calculating the sum of all the elements inside the numpy array.We just need to call the function using the numpy array reference.The syntax for using the sum function is array_ref.sum().

Following code snippet specifies the same:

The first snippet declares the array and reshapes it into dimension of 5x4.In the next code snippet we calculate the sum of all the elements using the sum function and the result is 190.
2.prod
If we want to calculate the product of all the elements inside the arr_2 array we can use the prod function.The syntax to use the prod function is as follows: array_ref.prod().

Following code snippet specifies the code for the same:
The result of the prod function is negative because here the multiplication value tends to over shoot the range of the int data type.For further explanation you can refer these references:[1][2]

Next I have changed the contents of the arr_2 reference and also calculated the product to get the result value within the range of integer which is specified in the following code snippet:

3.min
For finding the minimum value inside the numpy array we can use the min() function. The min function returns minimum element as a return value.The syntax for using the min() function is as follows: array_ref.min()

Following code snippet specifies result of executing the min function on the arr_1 and arr_2.


4.argmin
Suppose if we want to get the index of the minimum value inside the array then we can use the argmin() function. The syntax for using the argmin() fuction is as follows: array_ref.argmin().

Following code snippet specifies the same:
In the code snippet specified above the argmin function contains an argument which specifies the axis value.Axis value specifies the direction to perform the given operation.Axis = 1 specifies the direction as Horizontal and Axis = 0 means the direction to perform the operation is Vertical.

If we just want to find the index of the minimum value over the entire array then we can refer the below code snippet:



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References:
1.https://stackoverflow.com/questions/39089618/why-is-numpy-prod-incorrectly-returning-negative-results-or-0-for-my-long-li
2.https://stackoverflow.com/questions/1658714/how-to-get-the-range-of-valid-numpy-data-types/1658755#1658755
 
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