\input{figures/pseudo-code/c45.tex}
j48/C4.5\cite{c4.5} is based in the ID3 tree learner. C4.5 chooses what column to use and what value(s) to split on when creating the rule tree based off of normalized information gain of the
attributes. Once an attribute is chosen, new child nodes are created
for each of the values present in the chosen attribute. The algorithm
then recurses on each of the children nodes. This differs from standard rule trees in that there are many rules at each splitting point, rather than one rule. This means that C4.5 does not choose a rule per say, but an attribute to split on. For discrete attributes, this can cause one rule for each value. Continuous attributes will create one rule for each discretized range. After the rules have been created, a pruning process is applied to reduce the overall error rate of the rules.
