网页首先,建立ODE,. y^ {\prime}=f (x, y), \quad y\left (x_ {0}\right)=y_ {0}, \quad x_ {0} \leq x \leq x_ {n} \\. 可将其表示为,. y_ {i+1}=y_ {i}+h \varphi\left (x_ {i}, y_ {i}\right) \\. 再令 \varphi\left (x_ {i}, y_ {i}\right)=a_ {1} k_ {1}+a_ {2} k_ {2}+a_ {3} k_ {3}+a_ {4} k_ {4},可得到.