University of the Philippines Manila (UPM) invited us to talk about our research in Bioinformatics. I will discuss our research on visualization of yeast gene expression data.
You can download the pdf using the link below
Definition 1. The inner product of two vectors x and y is
The Euclidean Norm of vector x is ||x||
If ||x|| = 1, then x is normalized
Otherwise, we can normalize x to x’ as follows
Vector x and y are orthogonal, if their scalar product is zero.
Geometric interpretation is shown below
Note that the orthogonal projection of y onto x is
is useful when
- the pattern exists.
- it is difficult to pin down the problem mathematically.
- you have a data.
Pattern is an entity vaguely defined that could be given a name
Examples of patterns are palindromes in a sequence, spatial configuration of pixels in character recognition, speech signal in spectrogram, the salary, age, and debt records in credit card applications.
Learning is a process by which parameters of a learning machine are modified through a continuous process of stimulation by the environment in which it is embedded.
In Figure 1, parameters of the learning machine are tweaked based from the error signal.
- Supervised Learning -with the help of a teacher
- Unsupervised Learning – with the help of a critic
Why unsupervised learning is important?
It is important because it may lead to a new pattern, thus leading to knowledge discovery.