Introduction to Chaos Game Representation (CGR)

Problem at Hand

Genomic Sequence

Example

ACGAGTTACGGT

ACGCGTAGACGT

GTCATGCATAACT

ACGAGTTACGGT

ACGCGTAGACGT

GTCATGCATAACT

How to compare?🤔🤔

ACGAGTTACGGT

ACGCGTAGACGT

GTCATGCATAACT

How to compare?🤔🤔

That is, how do we bring about a proper numerical representation?

Any Ideas?

Iterated Function Systems (IFS)

Iterated Function Systems (IFS)

What is 

A\cdot x

Iterated Function Systems (IFS)

What is 

y = A\cdot x

Iterated Function Systems (IFS)

What is 

y = A\cdot x

Think of "A" as a "Transformation" on x

Iterated Function Systems (IFS)

y = A\cdot x

Think of "A" as a "Transformation" on x

\begin{bmatrix} 1 \\ 0 \end{bmatrix}
\begin{bmatrix} 0.5 & 3 \\ 0.5 & 4 \end{bmatrix}
A

Iterated Function Systems (IFS)

y = A\cdot x

Think of "A" as a "Transformation" on x

\begin{bmatrix} 1 \\ 0 \end{bmatrix}
\begin{bmatrix} 0.5 & 3 \\ 0.5 & 4 \end{bmatrix}
A
\begin{bmatrix} 0.5 \\ 0.5 \end{bmatrix}

Iterated Function Systems (IFS)

y = A\cdot x

Think of "A" as a "Transformation" on x

\begin{bmatrix} 1 \\ 0 \end{bmatrix}
\begin{bmatrix} 0 & -1 \\ 1 & 0 \end{bmatrix}
A
\begin{bmatrix} 0 \\ 1 \end{bmatrix}
\begin{bmatrix} 1 \\ 0 \end{bmatrix}

Iterated Function Systems (IFS)

y = A\cdot x
\begin{bmatrix} 0 & -1 \\ 1 & 0 \end{bmatrix}
A
\begin{bmatrix} 1 \\ 0 \end{bmatrix}
\begin{bmatrix} cos(\theta) & -sin(\theta) \\ sin(\theta) & cos(\theta) \end{bmatrix}
\theta=\frac{\pi}{2}

"Rotation Matrix"

Iterated Function Systems (IFS)

y = \begin{bmatrix} a & b \\ c & d \end{bmatrix} \cdot x + \begin{bmatrix} e \\ f \end{bmatrix}
\begin{bmatrix} 0 & -1 \\ 1 & 0 \end{bmatrix}
A
\begin{bmatrix} 1 \\ 0 \end{bmatrix}
\begin{bmatrix} cos(\theta) & -sin(\theta) \\ sin(\theta) & cos(\theta) \end{bmatrix}
\theta=\frac{\pi}{2}

"Rotation Matrix"

To Define such a generic linear transform, We will need 6 parameters: a,b,c,d,e,f

Iterated Function Systems (IFS)

Iterated Function Systems (IFS)

Now, We shall consider a "Set of Such Transforms"

a b c d e f
1 0.5 0.5
2 0.5 0.5 0.5
3 0.5 0.5 0.5 0.5

Iterated Function Systems (IFS)

Do This Repetedly

Other Transformations

Chaos Game Representation

Chaos Game Representation

Chaos Game Representation

Chaos Game Representation

Chaos Game Representation

Chaos Game Representation

Chaos Game Representation

CC AC CA AA
GC TC GA TA
CG AG CT AT
GG TG GT TT

C

A

T

G

Introduction to Chaos Game Representation

By Incredeble us

Introduction to Chaos Game Representation

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