1 ;; The first three lines of this file were inserted by DrScheme. They record metadata
2 ;; about the language level of this file in a form that our tools can easily process.
3 #reader(lib "htdp-advanced-reader.ss" "lang")((modname |29.3|) (read-case-sensitive #t) (teachpacks ((lib "draw.ss" "teachpack" "htdp") (lib "arrow.ss" "teachpack" "htdp") (lib "gui.ss" "teachpack" "htdp"))) (htdp-settings #(#t constructor repeating-decimal #t #t none #f ((lib "draw.ss" "teachpack" "htdp") (lib "arrow.ss" "teachpack" "htdp") (lib "gui.ss" "teachpack" "htdp")))))
4 ;norm : vector -> number
5 ;Produces the square root of the sum of the numbers in avector.
6 
7 (define (norm avector)
8   (sqrt (sum-of-squares avector 0)))
9 
10 ;sum-of-squares : vector N -> number
11 ;Given avector and i, square the element in avector from [i,vector-length) and then sum them 
12 
13 (define (sum-of-squares avector i)
14   (cond
15     [(= (vector-length avector) i) 0]
16     [else (+ (sqr (vector-ref avector i))
17              (sum-of-squares avector (add1 i)))]))