corrected inversion of params

tpEdo/tpEquadiffs.md

@@ -77,10 +77,10 @@ y_{n+1}=y_n+\frac{1}{6}(k_1+2(k_2+k_3)+k_4),
 $$
 où
 \begin{align}
-k_1&=\delta tF(t_n, y_n),\\
-k_2&=\delta tF\left(t_n+\frac{\delta t}{2}, y_n+\frac{k_1}{2}\right),\\
-k_3&=\delta tF(t_n+\frac{\delta t}{2}, y_n+\frac{k_2}{2}),\\
-k_4&=\delta tF(t_n+\delta t, y_n+k_3).
+k_1&=\delta tF(y_n, t_n),\\
+k_2&=\delta tF\left(y_n+\frac{k_1}{2}, t_n+\frac{\delta t}{2}\right),\\
+k_3&=\delta tF(y_n+\frac{k_2}{2}, t_n+\frac{\delta t}{2}),\\
+k_4&=\delta tF(y_n+k_3, t_n+\delta t).
 \end{align}
 
 ## L'équation de Lorenz