# RungeKuttaPlot: Plots the steps in runge-kutta methods In diffEq: Functions from the book Solving Differential Equations in R

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## Usage

 `1` ```rkMethodPlot (rk, ...) ```

## Arguments

 `rk ` A list containing the runge-kutta coefficients, implicit or explicit, e.g. matrix `A`, vectors `b1`, `b2`, codec. The list can be of type `rkMethod`, as defined in package `deSolve`. `... ` arguments passed to the plotting function.

Returns nothing

## Author(s)

Karline Soetaert

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26``` ```# This to plot all runge kutta methods #RKS <- rkMethod() #for (i in 4:21) rkMethodPlot( rkMethod(RKS[i])) ## ----------------------------------------------------------------------------- ## Figures A and B: Cash-Karp and Radau 5 steps ## ----------------------------------------------------------------------------- par(mfrow=c(2,2)) rkMethodPlot( rkMethod("rk45ck"), main="Cash-Karp") writelabel("A") rkMethodPlot( rkMethod("irk5"), main="Radau5") writelabel("B") rkMethodPlot( rkMethod("rk45dp6"), main="Dopri") writelabel("C") rkMethodPlot( rkMethod("irk6l"), main="Lobatto") writelabel("D") legend("bottomright", pch = c(16, 16, 1, NA), pt.cex = c(1.5, 1.5, 1), legend = c(expression(y[0]), expression(y[1]), "intermediary", "k"), col = c("grey", "black", "black", "black"), lty = c(NA, NA, NA, 1), lwd = c(1, 1, 1, 2)) ```