# Passing variable with line types to ggplot linetype

I am new to ggplot so bear with me. I am charting out growth projections for 35 small-area geographies which is an unhealthy amount for one plot even with use of the fantastic `directlabels`

library. However I need all the series for initial screening.

The challenge is to make it readable. I found a fix by @Ben Bolker for using large numbers of distinct colors but am having trouble varying the linetype. The 35 series don't need to be unique, but I would like to use the 12 different types to make individual series easier to read.

My plan was to create a random list with 35 elements of the 12 possible types and pass that as the linetype argument, but I am having trouble getting it to work, with the error:

I have 35 values in the linetype list. Of course I would like for the types, colors and all to be reflected in the legend.

The melted data looks like this; 9 years' observations for each of 35 series:

> simulation_long_index[16:24,] year geography value 16 2018 sfr_2 101.1871 17 2019 sfr_2 101.1678 18 2020 sfr_2 101.2044 19 2012 sfr_3 100.0000 20 2013 sfr_3 100.1038 21 2014 sfr_3 100.2561 22 2015 sfr_3 100.0631 23 2016 sfr_3 100.8071 24 2017 sfr_3 101.2405

Here is my code so far:

lty <- data.frame(lty=letters[1:12][sample(1:12, 35,replace=T)]) g3<-ggplot(data=simulation_long_index, aes( x=as.factor(year), y=value, colour=geography, group=geography, linetype=lty$lty))+ geom_line(size=.65) + scale_colour_manual(values=manyColors(35)) + geom_point(size=2.5) + opts(title="growth")+ xlab("Year") + ylab(paste("Indexed Value (Rel. to 2012")) + opts(axis.text.x=theme_text(angle=90, hjust=0)) print(g3)

adding

scale_linetype_manual("",values=lty$lty) +

after scale_color_manual instead of the linetype argument produces the chart, but lines are all the same. How, then, do I get the lines to vary for large series counts?