Chekli ayirmalar usuli haqida tushunchalar

DASTUR-1
8 REM SAVE"xx’ar2.bas",a
10 REM DASTUR-1
12 REM parabolik TENGLAMASI UCHUN
14 REM ARALASH MASALASINI YeCHISH
16 REM
20 DIM U(60,60),X(60),T(60)
22 DEF FNF(X)=SIN(3.141593*X)
30 DEF FNF1(T)=0
40 DEF FNF2(T)=0
50 READ A,B,T1,H
52 INPUT" X argument yuqori chegarasi S ni kiring="; s
54 INPUT” X argument kesmasidagi bo‘linish kadami H ni kirieing=”; h
56 INPUT” T argument yuqori chegarasi T1 ni kiring="; t1
60 K=H*H/2 : N=(B-A)/H : M=T1/K
70 FOR I=0 TO N : X(I)=I*H
80 NEXT I
90 FOR J=0 TO M : T(J)=J*K
100 U(0,J)=FNF1(T(J)) : U(N,J)=FNF2(T(J)) :NEXT J
110 FOR I=0 TO N
120 U(I,0)=FNF(X(I))
130 NEXT I
140 FOR J=0 TO M : FOR I=1 TO N-1
150 U(I,J+1)=.5*(U(I-1,J)+U(I+1,J))
160 NEXT I : NEXT J : GOSUB 220 : PRINT ": T/X ";
170 FOR I=0 TO N-5 : PRINT " :";USING "##.####";X(I);:NEXT I: PRINT " :"
180 GOSUB 220
190 FOR J=0 TO M : PRINT ": ";USING "##.###";T(J);: FOR I=0 TO N-5
200 PRINT " :";USING "##.####";U(I,J);
210 NEXT I : PRINT " :" : GOSUB 220 : NEXT J : GOTO 250
220 PRINT "-----------"; : FOR I=0 TO N-5 : PRINT "---------"; : NEXT I
230 PRINT : RETURN
240 DATA 1,1,0.025,.1
250 END
RUN
----------------------------------------------------------------------------
: T/X : 0.0000 : 0.1000 : 0.2000 : 0.3000 : 0.4000 : 0.5000 :
----------------------------------------------------------------------------
: 0.000 : 0.0000 : 0.3090 : 0.5878 : 0.8090 : 0.9511 : 1.0000 :
-----------------------------------------------------------------------------
: 0.005 : 0.0000 : 0.2939 : 0.5590 : 0.7694 : 0.9045 : 0.9511 :
-----------------------------------------------------------------------------
: 0.010 : 0.0000 : 0.2795 : 0.5317 : 0.7318 : 0.8602 : 0.9045 :
-----------------------------------------------------------------------------
: 0.015 : 0.0000 : 0.2658 : 0.5056 : 0.6959 : 0.8181 : 0.8602 :
-----------------------------------------------------------------------------
: 0.020 : 0.0000 : 0.2528 : 0.4809 : 0.6619 : 0.7781 : 0.8181 :
-----------------------------------------------------------------------------
: 0.025 : 0.0000 : 0.2404 : 0.4574 : 0.6295 : 0.7400 : 0.7781 :
-----------------------------------------------------------------------------
Ok_