# APPENDIX 2

# Method of Least Squares

**T**he following programs, written in Microsoft FORTRAN for the IBM PC,^{1} solve the 2-variable regression analysis using the *method of least squares*. The program allows for the regression of two series against one another, and the regression of one series against time.

## OPERATING INSTRUCTIONS

In the following example, the user's entries are underlined:

LSTSQ
Enter data in sets of 2 (Y then X).
If second variable is omitted, sequential numbers will be used for x.
Extra <return> ends input.
Enter below:
YYYYYY XXXXXX
1.27 2.43
1.19 2.26
1.10 2.15
<RETURN>
Print data (Y/N)? Y
(Computer prints data and solutions)
Sample results (Y/N)?Y
Enter start, end and increments below
ssssss eeeeee iiiiii
1.00 7.00 .50
(Computer prints sample results)

Plot results (Y/N)?Y
Name for X-scale (9 chars)?
SOYBEANS
Name for Y-scale (9 chars)?
CORN
Which plot?
1: Linear
2: Logarithmic
3: Exponential
4: Curvilinear
Which number? 1
(Computer plots)
Another plot (Y/N)?Y
Which plot?
1: Linear
(and so forth)

## COMPUTER PROGRAMS

1 $TITLE: ‘LSTSQ: LEAST SQUARES’ 2 $SUBTITLE: ‘COPYRIGHT 1986 P J KAUFMAN’ 3 $STORAGE:2 4 PROGRAM LSTSQ 5 C---- Least Squares Regression Analysis for 2 variables 6 7 CHARACTER*1 ANS 8 DIMENSION X(100),Y(100) 9 10 DATA MAX/100/ 11 12 OPEN(6,FILE=‘PRN’) 13 14 C---- Read data in sets of 2 variables 15 I = 1 16 WRITE(*,7000) 17 7000 FORMAT(‘ Enter data in sets of 2 (Y then X).’/ 18 + ‘ If second variable is omitted, sequential numbers’, 19 + ‘ will ...