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 one_over_x = 1/(x+1.e-3) y_prime = -( exp(one_over_x) - cos(one_over_x)*y ) / ( x^2 * sin(one_over_x) ) dy[2] = y_prime list( dy ) } #postscript("../../WriteUp/Graphics/Chapter2/chap_2_sect_1_prob_26_plot.eps", onefile=FALSE, horizontal=FALSE) diff_eq_params = c() flowField(my_yprime, x.lim = c(1, 5), y.lim = c(-3, +6), parameters = diff_eq_params, points = 21, add = FALSE) trajectory(my_yprime, y0 = c(1.0, -1), t.start=1, t.end = 5, parameters = diff_eq_params) trajectory(my_yprime, y0 = c(1.0, +1), t.start=1, t.end = 5, parameters = diff_eq_params) trajectory(my_yprime, y0 = c(1.0, +2), t.start=1, t.end = 5, parameters = diff_eq_params) trajectory(my_yprime, y0 = c(1.0, +4), t.start=1, t.end = 5, parameters = diff_eq_params) #dev.off()