n
yi ' = fi (x, y 1, y 2, ¼, yn), i = 1, 2, ¼, n (4.2)
y 1(x 0) = y 10, y 2(x 0) = y 20, ¼, yn (x 0) = yn 0. (4.3)
(4.2) (4.3) x 1, x 2, ¼, xN (x 0 < x 1 < x 2 < ¼ < xN) y 1(x), y 2(x), ¼, yn (x), , .. n
[ yi (x 1), yi (x 2), ¼, yi (xN)] i = 1, 2, ¼, n.
, , yk yik (yik = yi (xk)) fk fik (fik = fi (xk, y 1 k, y 2 k, ¼, ynk)). , (2)
{ yi (k +1) = yik + hfik } i = 1, 2, ¼, n.
y '' = f (x, y, y ') (4.4)
y (x 0) = y 0, y '(x 0) = y 0'. (4.5)
y = y (x), , x 1, x 2, ¼, xn (x 0 < x 1 < x 2 < ¼ < xn). y '(x).
y ' = z.
(4.4) (4.5) :
, h 5:
x | v 0 = y | v 1 = hy ' | k = | |
x 0 | v 00 | v 10 | k 1 | |
x 0 + h /2 | v 00 + v 10/2 + k 1/4 | v 10 + k 1 | k 2 | |
x 0 + h /2 | v 00 + v 10/2 + k 2/4 | v 10 + k 2 | k 3 | |
x 0 + h | v 00 + v 10 + k 3 | v 10 + 2 k 3 | k 4 | |
x 1 = x 0 + h | v 01 = v 00 + v 10 + k (0) | v 11 = v 10 + k (1) | ||
k (0) = (k 1 + k 2 + k 3)/3, k (1) = (k 1 +2 k 2 + 2 k 3 + k 4)/3 |
:
:
, (7).
8
[0, a ]. a . 5 .
, . , - .
a | b | |||
1.1 | 2.1 | 0.4 | ||
-"- | 1.2 | 2.2 | -"- | |
-"- | 1.3 | 2.3 | -"- | |
-"- | 1.4 | 2.4 | -"- | |
-"- | 1.5 | 2.5 | -"- | |
1.1 | 2.1 | 0.4 | ||
-"- | 1.2 | 2.2 | -"- | |
-"- | 1.3 | 2.3 | -"- | |
-"- | 1.4 | 2.4 | -"- | |
-"- | 1.5 | 2.5 | -"- | |
1.1 | 2.1 | 0.6 | ||
-"- | 1.2 | 2.2 | -"- | |
-"- | 1.3 | 2.3 | -"- | |
-"- | 1.4 | 2.4 | -"- | |
-"- | 1.5 | 2.5 | -"- | |
1.1 | 2.1 | 0.6 | ||
-"- | 1.2 | 2.2 | -"- | |
-"- | 1.3 | 2.3 | -"- | |
-"- | 1.4 | 2.4 | -"- | |
-"- | 1.5 | 2.5 | -"- | |
1.1 | 2.1 | 0.4 | ||
-"- | 1.2 | 2.2 | -"- | |
-"- | 1.3 | 2.3 | -"- | |
-"- | 1.4 | 2.4 | -"- | |
-"- | 1.5 | 2.5 | -"- |
|
|
a | b | |||
1.1 | 2.1 | 0.8 | ||
-"- | 1.2 | 2.2 | -"- | |
-"- | 1.3 | 2.3 | -"- | |
-"- | 1.4 | 2.4 | -"- | |
-"- | 1.5 | 2.5 | -"- | |
1.1 | 2.1 | 0.8 | ||
-"- | 1.2 | 2.2 | -"- | |
-"- | 1.3 | 2.3 | -"- | |
-"- | 1.4 | 2.4 | -"- | |
-"- | 1.5 | 2.5 | -"- | |
1.1 | 2.1 | 0.5 | ||
-"- | 1.2 | 2.2 | -"- | |
-"- | 1.3 | 2.3 | -"- | |
-"- | 1.4 | 2.4 | -"- | |
-"- | 1.5 | 2.5 | -"- | |
1.1 | 2.1 | 0.8 | ||
-"- | 1.2 | 2.2 | -"- | |
-"- | 1.3 | 2.3 | -"- | |
-"- | 1.4 | 2.4 | -"- | |
-"- | 1.5 | 2.5 | -"- | |
1.1 | 2.1 | 1.0 | ||
-"- | 1.2 | 2.2 | -"- | |
-"- | 1.3 | 2.3 | -"- | |
-"- | 1.4 | 2.4 | -"- | |
-"- | 1.5 | 2.5 | -"- |
1. . , Maple :
Maple , , . .
2. Mathcad, . , Scatterplot /