Assignment #3 - 90A
Assignment #3 - 90A
ASSIGNMENT 3
DUE DATE Feb 6 90 (WEIGHT 25)
WRITE A PROGRAM TO FIND THE LEAST SQUARES FIT TO A SET OF
DATA ACCORDING TO THE EXPRESSION GIVEN BELOW.
Y(1), Y(2), Y(3), ... , Y(N) ARE READINGS THAT VARY WITH
THE VALUES X(1), X(2), X(3), ... , X(N) OF AN INDEPENDENT
VARIABLE X.
EACH PAIR OF VALUES, (X AND Y) ARE CONTAINED ON ONE CARD. THE
DATA SET IS TERMINATED BY A "DUMMY LINE" WITH X AND Y BOTH
NEGATIVE.
THE EQUATION OF A STRAIGHT LINE IS
Y = AX + B
AND THE BEST STRAIGHT LINE FOR THE GIVEN DATA IS GIVEN BY
N*SXY - SX*SY
A = -------------
N*SX2 - SX*SX
SY*SX2 - SX*SXY
B = ---------------
N*SX2 - SX*SX
N NUMBER OF (X,Y) PAIRS
SX SUM OF X'S
SY SUM OF Y'S
SX2 SUM OF X*X'S
SXY SUM OF X*Y'S
DRAW A PENCIL SKETCH ON YOUR OUTPUT SHOWING THE INPUT DATA AND THE
LEAST SQUARES FIT LINE. YOUR PROGRAM SHOULD PROCESS TWO SETS OF
DATA, THE ONE GIVEN BELOW AND A SET OF YOUR OWN.
SAMPLE DATA:
2.8 8.0
7.0 1.5
3.8 7.2
0.2 12.1
2.0 10.5
4.0 6.0
6.1 3.6
6.9 3.6
7.6 2.2
4.1 5.0
5.3 5.0
4.0 8.5
-1.0 -1.0
Note: This program can be done either using ARRAYS or without them,
For five extra bonus marks, do hand in BOTH!