## With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

No credit card required

# Fourier Transformation

The original computer program that solves the Fourier transformation as described by Jack Hutson and Anthony Warren (Technical Analysis of Stocks & Commodities) is based on the Cooley-Tukey Fast Fourier Transform Algorithm (1965), developed at the IBM Thomas J. Watson Research Center. A full explanation of this program and its interpretation can be found in the two articles that appeared in the January 1983 edition of Technical Analysis of Stocks & Commodities, then reprinted in the September 1986 issue.

The following program appeared in the September 1986 issue of Technical Analysis of Stocks & Commodities. It was written by John Ehlers and appended to the article “A Comparison of the Fourier and Maximum Entropy Methods.”

## FAST FOURIER TRANSFORM PROGRAM

```10 REM “FAST FOURIER TRANSFORM”
20 REM FOR APPLE ][ WITH 2 DISKS USING
30 REM DATA IN CSI OR COMPU-TRAC FORMAT
40 REM BY JOHN F. EHLERS
45 REM COPYRIGHT (C) 1986 BY TECHNICAL ANALYSIS, INC.
50 HOME
60 DIM DF\$(20)
70 HTAB 5: INVERSE : PRINT “* FAST FOURIER TRANSFORM *” :
NORMAL
71 HTAB 19: PRINT “BY”
72 HTAB 14: PRINT “JOHN EHLERS”
73 HTAB 16: PRINT “BOX 1801”
74 HTAB 12: PRINT “GOLETA, CA 93116”: PRINT
80 LET D\$ = CHR\$(4)
90 PRINT D\$ + “OPEN MASTER,L40,D2”
100 FOR I = 1 TO 20```
` 110 PRINT D\$ + “READ MASTER,R”;I 120 INPUT DF\$(I) 130 IF LEFT\$ (DF\$(I),5) = “99999” GOTO 150 140 NEXT I 150 PRINT D\$ + “CLOSE” 160 FOR J = 1 TO I–1 170 PRINT “<”; CHR\$ (J + 64); “>”; MID\$ (DF\$(J),4,16) 180 NEXT J 190 ...`

## With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

No credit card required