# Category : Miscellaneous Language Source Code

Archive : FORTRN77.ZIP

Filename : STEXTN.FOR

C

C THIS SUBROUTINE DETERMINES THE INTERCEPT, SLOPE AND GROWTH RATE

C OF AN EXPONENTIAL TREND OF THE TYPE Y = AA*(C**(AA*X)).

C

DIMENSION X(1), Y(1)

SX = 0.

SY = 0.

SXY = 0.

SXX = 0.

DO 1 I = 1,N

IF (D) 2,3,2

3 Y(I) = ALOG(Y(I))*0.43429

GO TO 10

2 Y(I) = ALOG(Y(I))

10 SX = SX + X(I)

SY = SY + Y(I)

SXY = SXY + X(I)*Y(I)

SXX = SXX + X(I)*X(I)

1 CONTINUE

FN = N

B = (FN*SXY - SX*SY)/(FN*SXX - SX*SX)

A = (SY*SXX - SX*SXY)/(FN*SXX - SX*SX)

IF (D) 6,5,6

5 AA = 10.**A

BB = B/(ALOG(C)*0.43429)

GO TO 7

6 AA = EXP(A)

BB = B/ALOG(C)

7 RATE = C**BB - 1.

RETURN

END

Very nice! Thank you for this wonderful archive. I wonder why I found it only now. Long live the BBS file archives!

This is so awesome! 😀 I’d be cool if you could download an entire archive of this at once, though.

But one thing that puzzles me is the “mtswslnkmcjklsdlsbdmMICROSOFT” string. There is an article about it here. It is definitely worth a read: http://www.os2museum.com/wp/mtswslnk/