1 REM PAR J.F. SEHAN
2 REM EXTRAIT DU LIVRE
3 REM "ETUDES POUR ZX81"
4 REM TOME 2
5 REM 
10 REM HISTOGRAMME
20 REM 
30 LET G=10240
40 PRINT AT 21,0;"TITRE ?"
50 INPUT T$
100 PRINT AT 21,0;"ENTRER L ECHELLE VERTICALE ?    "
110 INPUT EV
120 PRINT AT 21,0;"NOMBRE DE DONNEES ?         "
130 INPUT ND
140 IF ND>25 THEN GOTO 130
190 REM ENTREE DES DONNEES
200 DIM D(ND)
210 CLS
220 FOR I=1 TO ND
230 PRINT AT 21,0;"DONNEE ";I;" ?"
240 INPUT D(I)
250 IF D(I)>EV THEN GOTO 230
260 NEXT I
480 REM 
490 REM TRACE DES AXES
500 LET A=0
510 LET B=0
520 LET C=160
530 LET D=250
540 LET F=164
550 LET E=EV
560 LET L=USR G
570 REM BL CL MO B A DR B C DR D C
580 LET IV=EV/10
590 FOR I=0 to 9
600 LET A$=STR$(E)+"      "
610 LET A$=A$(1 TO 6)
620 LET Y=I*16
630 LET L=USR G
640 REM MO A Y PR A$ DR B Y
650 LET E=E-IV
660 NEXT I
670 LET H=ND
680 LET K=168
690 LET P=176
700 LET IH=200/ND
710 FOR I=250 TO 45 STEP -IH
720 LET A$=STR$(H)+" "
730 LET B$=A$(1 TO 1)
740 LET C$=A$(2 TO 2)
750 LET L=USR G
760 REM MO I K PR B$ MO I F DR I C MO I P PR C$
780 LET H=H-1
800 NEXT I
810 LET Y=182
820 LET L=USR G
830 REM MO A Y PR T$
840 REM 
850 REM HISTOGRAM
900 FOR I=0 TO ND-1
910 LET K=160-((D(I+1)/EV)*160)
920 FOR J=0 TO IH
930 LET P=IH*I+J+50
940 LET L=USR G
950 REM MO P C DR P K
960 NEXT J
970 NEXT I
980 REM 
990 REM IMPRESSION ET FIN
1000 IF INKEY$="" THEN GOTO 1000
1010 IF INKEY$<>"P" THEN GOTO 1040
1020 LET L=USR G
1030 REM COPY
1040 CLS
1050 POKE G,0

