Dear all,

I want to make a plot where I can specify the range of y axis. I am using the interaction.plot command and because the values of y axis are from 2 to 500, I am using a logarithmic scale.

>interaction.plot(speclong$Date,speclong$time2,speclong$outcome,xaxt="n",type="l",pch=20,xlab="", log="y", ylab="Concentration (ug/L)",trace.label="",col=rainbow(7))



The plot itself gives me a y scale displaying ticks at 2, 5, 10, 20, 100, 200, 500. I would like to get a y scale where it would display ticks at every 4 marks, at 2, 20, 100 and 500.



I tried ylim=c(2,20,100,500) but nothing happened. Actually I got an error.



Could you help me?



Thank you.



Maria


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