Page 99 - Chapra y Canale. Metodos Numericos para Ingenieros 5edición_Neat

3.4 ERRORES DE REDONDEO 75

a) Programa
PROGRAM fi g0312
IMPLICIT none
Real::term, test, sum,x
INTEGER::i
i = 0
term = 1.
sum = 1.
test = 0.
PRINT *, ‘x = ’
READ *, x
PRINT *, ‘i’, ‘term’, ‘sum’
DO
IF (sum.EQ.test) EXIT
PRINT *, i, term, sum
i = i + 1
term = term*x/i
test = sum
sum = sum+term
END DO
PRINT *, ‘valor exacto =’ ,exp(x)
END
b) Evaluación de e 10 c) Evaluación de e –10

x= x=
10 -10
i term sum i term sum
0 1.000000 1.000000 0 1.000000 1.000000
1 10.000000 11.000000 1 –10.000000 –9.000000
2 50.000000 61.000000 2 50.000000 41.000000
3 166.666700 227.666700 3 –166.666700 –125.666700
4 416.666700 644.333400 4 416.666700 291.000000
5 833.333400 1477.667000 5 –833.333400 –542.333400
. .
. .
. .
27 9.183693E-02 22026.420000 1 –2.989312E-09 8.137590E-05
28 3.279890E-02 22026.450000 42 7.117410E-10 8.137661E-05
29 1.130997E-02 22026.460000 43 –1.655212E-10 8.137644E-05
30 3.769989E-03 22026.470000 44 3.761845E-11 8.137648E-05
31 1.216126E-03 22026.470000 45 –8.359655E-12 8.137647E-05
valor exacto = 22026.460000 valor exacto = 4.539993E-05
FIGURA 3.12
x
x
–x
a) Un programa en Fortran 90 para evaluar e usando series infi nitas. b) Evaluación de e . c) Evaluación de e .

6/12/06 13:44:17
Chapra-03.indd 75
Chapra-03.indd 75 6/12/06 13:44:17