Add lines for the density of infected individuals for the garki model

xds_lines_X_garki(times, XH, pars, clrs = viridisLite::turbo(8), llty = 1)

Arguments

times: time points for the observations
XH: a list with the outputs of parse_outputs_X_SIS
pars: a list that defines an ramp.xds model (e.g., generated by make())
clrs: a vector of colors
llty: an integer (or integers) to set the lty for plotting