public static <T extends Comparable<? super T>> T q1(T[] a) {
        int k = a.length / 4;
        return select(a, k);
    }
public static < T extends Comparable < ? super T > > T q1 ( T [ ] a ) { int k = a . length / 4 ; return select ( a , k ) ; }
Find the first quantile (p = 1/4) of an array of type double.