if( !require('phaseR') ){ install.packages('phaseR') } library(phaseR) my_yprime = function(t, y, parameters){ x = y[1] y = y[2] dy = numeric(2) dy[1] = 1 dy[2] = -x*y + 0.1*y^3 list( dy ) } #postscript("../../WriteUp/Graphics/Chapter2/chap_2_sect_7_prob_8_plot.eps", onefile=FALSE, horizontal=FALSE) diff_eq_params = c() logistic.flowField <- flowField(my_yprime, x.lim=c(0, 4), y.lim=c(-9, 9), parameters=diff_eq_params, points=21, add=FALSE, main='Problem 8') #dev.off()