A Function is a deterministic mapping from a set of input value to one or more output value.
function(input)= Output
eg: Multiplication function
function multi(5,5)=25
Why is extracting a function from data useful?
- Once a function has been extracted from a dataset, it can be applied to unseen data.
- Spam filtering is a function that takes an email as input and returns a value that classifies the email as spam or not spam.
- Face recognition is a function that takes an image as input and returns a labelling of the pixels in the image that demarcates the face in the image.
- Gene prediction is a function that takes a genomics DNA sequence as input and return the region of the DNA that encode a gene.
- Speech Recognition is a function that takes an audio speech signal as input and returns a textual transcription of the speech.
- Machine translation is a function that takes a sentence in one language as input and return the translation of the sentences in another languages.
If you want to know more about function:
https://dlmf.nist.gov/
https://cloud.google.com/bigquery/docs/reference/standard-sql/mathematical_functions
https://www.maths.ox.ac.uk/groups/functional-analysis
