Centralia Junior High School
Centralia, Illinois
Math and Computers
(All rights reserved. Do not reproduce without permission.)

Prime Sieve in Action created with LOGO

Using pcLogo for Windows, Harvard Associates, Inc.

Click Here to view Logo Procedures for MSW Logo.

 

The Logo procecures listed here create these results with action color and sound to illustrate a prime sieve.

TO PRIMES
FS CS HT PU
SETPC 12 SETFONT "TIMES 16 1
SETXY [-85 220] PD TT [PRIME SIEVE]
SETPC 1 SETFONT "COURIER 12 1
PRNTARRAY 2
SIEVE 2 2
SIEVE 3 3
SIEVE 5 5
SIEVE 7 7
SIEVE 11 11
SIEVE 13 13
WAITKEY CS SS
END

TO PRNTARRAY :N
IF :N 200 [STOP]
PU SETXY CALCPOS :N PD
TT :N
PRNTARRAY :N + 1
END

TO SIEVE :N :I
IF :I * :N 200 [STOP]
SETPC 12
PU SETXY CALCPOS :I * :N
PD TT :N * :I TONE :N * 80 4
SETPC 7 TT :N * :I
SIEVE :N :I + 1
END

TO CALCPOS :N
MAKE "X (4 * REMAINDER (:N - 1) 10)
IF :N <10 [MAKE "X :X + 1]>
IF :N <100 [MAKE "X :X + 1]>
MAKE "Y (INT (:N - 1) / 10)
OP LIST 10 * :X - 220 180 - 20 * :Y
END

TO WAITKEY
IF KEY? [STOP]
WAITKEY
END

Type PRIMES in the listener window after defining the procedures in the editor window.


[ Return to Main Logo Page ] [ Return to CJHS Page ]