1 REM **** HP BASIC PROGRAM LIBRARY ******************************* 2 REM 3 REM ROOTNL: FINDS THE ROOTS OR FIXED POINTS OF A 4 REM NON-LINEAR FUNCTION 5 REM 36697 REV A 10/73 6 REM 7 REM **** CONTRIBUTED PROGRAM ************************************ 9000 REM ROOTNL--LOCATES THE ROOTS OF A NON-LINEAR FUNCTION 9002 PRINT 9004 PRINT "SUPPLY STARTING VALUE." 9006 INPUT X 9008 IF X=999999. THEN 9999 9010 PRINT 9012 PRINT " X","F(X)" 9014 PRINT 9016 GOSUB 9050 9018 LET X1=X 9020 LET X=Y 9022 FOR I=1 TO 10 9024 LET X2=X1 9026 LET X1=X 9028 LET Y1=Y 9030 GOSUB 9050 9032 PRINT X,Y 9034 IF Y=Y1 THEN 9054 9036 LET X=(X2*Y-X*Y1)/(Y-Y1) 9038 NEXT I 9040 PRINT "SUPPLY 0 FOR 10 MORE ITERATIONS, 1 TO RESTART." 9042 INPUT W 9044 IF W=0 THEN 9022 9046 IF W=1 THEN 9002 9048 STOP 9050 LET Y=SIN(X)-COS(X) 9052 RETURN 9054 PRINT 9056 PRINT "DIVISION BY 0." 9058 PRINT "SUPPLY A NEW STARTING VALUE OR TYPE 999999 TO STOP." 9060 GOTO 9006 9999 END