Hey! I'm trying to add a straight line to my anova plot, which I've created with ezplot: ezPlot(Ret2_combined, dv=accuracy, wid= participant,within= stimPos , between= ageGroup,x=ageGroup, split=stimPos,
x_lab= "Average accuracy in naming the preceding picture in relation to stimulus position in young adults and children")
I've tried using the command abline(a=0.33, b=0), but R returns the error message: "error in int_abline(a = a, b = b, h = h, v = v, untf = untf, ...) :
plot.new has not been called yet"
Can someone help me?
Thanks! 