I am looking for different ways to partition $R$. I know some like :
(1) Define a relation as following $$x\sim y \ \text{iff} \ x-y\in\mathbb Q(x,y\in\mathbb R)$$. The equivalence classes have the form $[r]=r+\mathbb Q$ and clear they are countable dense and pairwise disjoint and $\mathbb R=\bigcup_{r\in\mathbb R} [r]$.
(2) Let $P$ be the family of all nonempty perfect subsets of $\mathbb R$ so $|P\times\mathbb R|=c.$ Then we can enumerate $P\times\mathbb R$ as follows $\{<P_{\xi},y_{\xi}>\colon\xi<c\}$. Notice that each perfect will appear $c$ many time as first pair. We will construct by induction on $\xi$ a sequence $\{x_\xi\colon \xi<c\}$ such that
$$x_{\xi}\in P_{\xi}\setminus\{x_{\zeta}\colon \zeta<\xi\}$$
Since each $x_{\lambda}\neq x_{\xi}$ for all $\lambda<\xi$ so we can define $f$ on $\{x_\xi\colon \xi<c\}$ such that $f(x_{\xi})=y_{\xi}$ and $f(x)=0$ otherwise, Thus, $f$ has a desired property. It is not hard to see $f^{-1}(r)$ for each $r\in\mathbb R$ and perfect set $P$ we have $$f^{-1}(r)\cap P\neq\emptyset$$ and $$f^{-1}(r)\cap (R\setminus P)\neq\emptyset$$ $\mathbb R=\bigcup_{r\in\mathbb R} f^{-1}(r).$ Notice that $f^{-1}(r)$ is dense as well. $c$ is the cardinality for $\mathbb R.$
(3) Also, in John C, Oxtoby, Measure and Category, $\mathbb R$ can be written as union of meager set and null set.
My question is I want to see more interesting partition by using transfinite induction. Please Share you your ways if you know some. Thank in advance.