I am struggling to make a legend that I want for my graph. Here is what the graph currently looks like (it’s not a final version, I know it’s not super pretty)

I am frustrated by the fact that I can’t seem to combine the legends into one using patchwork or ggarrange packages. I am used to using scale_fcn_manual() and making the aesthetic calls identical, then calling for “collected” legends in patchwork(). However, because the data within each plot is actually different, it is still making them into 3 separate plots, despite the fact that I have all possible treatment options in my code.

Does anyone know how to either create an entirely new legend from scratch or fix my code? I have tried using a common legend using ggarrange() as well, but got a similar result. Below, I will include my ggplot code and also what I would LIKE the figure to look like, manually edited on Paint. Thanks!

plot_size_p = ggplot (filter(snail_size, food %in% c("C","J","K","L")), aes(x = week, y = mean_size, color = food, shape=infected, linetype=infected)) +
  theme_bw()+
  theme(plot.title = element_text(hjust = 0.5,vjust=-1))+
  theme(legend.position = "right")+
  theme(legend.title.align=0.5)+
  labs(color = "Resource Type",
       linetype = "Parasite Status",
       shape = "Parasite Status")+
  ggtitle("PnSupplement")+
  xlab("Week")+
  ylab("Mean Shell Diameter (mm)")+
  geom_linerange(aes(ymin=mean_size-SEM_size, ymax=mean_size+SEM_size, color=food)) +
  geom_point (aes(color = food, shape=infected)) +
  geom_line (aes(color = food, linetype=infected))+
  scale_x_continuous(breaks=seq(0,max(exp_size$week),by=4), limits=c(0,max(exp_size$week)))+
  scale_y_continuous(breaks=seq(6,15,by=2), limits=c(5.5,15.5))+
  scale_color_manual(breaks = c("F","I","H","G","L","K","J","O","N","M","C"),labels = c("100% Pleco Wafers","High N","Med N","Low N","High P","Med P","Low P","High (N+P)","Med (N+P)","Low (N+P)", "Baseline"),values = c("green4", brewer.pal(9, "Reds")[7],brewer.pal(9, "Reds")[6],brewer.pal(9, "Reds")[5],brewer.pal(9, "Blues")[7],brewer.pal(9, "Blues")[6],brewer.pal(9, "Blues")[5],brewer.pal(9, "Purples")[7],brewer.pal(9, "Purples")[6],brewer.pal(9, "Purples")[5], "grey"))+
  scale_linetype_manual(breaks=c(0,1), labels=c("Uninfected","Infected"), values=c(1,2))+
  scale_shape_manual(breaks=c(0,1), labels=c("Uninfected","Infected"), values=c(19,17))

plot_size_n = ggplot (filter(snail_size, food %in% c("C","G","H","I")), aes(x = week, y = mean_size, color = food, shape=infected, linetype=infected)) +
  theme_bw()+
  theme(plot.title = element_text(hjust = 0.5,vjust=-1))+
  theme(legend.position = "right")+
  theme(legend.title.align=0.5)+
  labs(color = "Resource Type",
       linetype = "Parasite Status",
       shape = "Parasite Status")+
  ggtitle("NnSupplement")+
  xlab("Week")+
  ylab("Mean Shell Diameter (mm)")+
  theme(axis.title.y = element_blank(),
        axis.text.y = element_blank())+
  geom_linerange(aes(ymin=mean_size-SEM_size, ymax=mean_size+SEM_size, color=food)) +
  geom_point (aes(color = food, shape=infected)) +
  geom_line (aes(color = food, linetype=infected))+
  scale_x_continuous(breaks=seq(0,max(exp_size$week),by=4), limits=c(0,max(exp_size$week)))+
  scale_y_continuous(breaks=seq(6,15,by=2), limits=c(5.5,15.5))+
  scale_color_manual(breaks = c("F","I","H","G","L","K","J","O","N","M","C"),labels = c("100% Pleco Wafers","High N","Med N","Low N","High P","Med P","Low P","High (N+P)","Med (N+P)","Low (N+P)", "Baseline"),values = c("green4", brewer.pal(9, "Reds")[7],brewer.pal(9, "Reds")[6],brewer.pal(9, "Reds")[5],brewer.pal(9, "Blues")[7],brewer.pal(9, "Blues")[6],brewer.pal(9, "Blues")[5],brewer.pal(9, "Purples")[7],brewer.pal(9, "Purples")[6],brewer.pal(9, "Purples")[5], "grey"))+
  scale_linetype_manual(breaks=c(0,1), labels=c("Uninfected","Infected"), values=c(1,2))+
  scale_shape_manual(breaks=c(0,1), labels=c("Uninfected","Infected"), values=c(19,17))

plot_size_np = ggplot (filter(snail_size, food %in% c("C","M","N","O")), aes(x = week, y = mean_size, color = food, shape=infected, linetype=infected)) +
  theme_bw()+
  theme(plot.title = element_text(hjust = 0.5,vjust=-1))+
  theme(legend.position = "right")+
  theme(legend.title.align=0.5)+
  labs(color = "Resource Type",
       linetype = "Parasite Status",
       shape = "Parasite Status")+
  ggtitle("(N+P)nSupplement")+
  xlab("Week")+
  ylab("Mean Shell Diameter (mm)")+
  theme(axis.title.y = element_blank(),
        axis.text.y = element_blank())+
  geom_linerange(aes(ymin=mean_size-SEM_size, ymax=mean_size+SEM_size, color=food)) +
  geom_point (aes(color = food, shape=infected)) +
  geom_line (aes(color = food, linetype=infected))+
  scale_x_continuous(breaks=seq(0,max(exp_size$week),by=4), limits=c(0,max(exp_size$week)))+
  scale_y_continuous(breaks=seq(6,15,by=2), limits=c(5.5,15.5))+
  scale_color_manual(breaks = c("F","I","H","G","L","K","J","O","N","M","C"),labels = c("100% Pleco Wafers","High N","Med N","Low N","High P","Med P","Low P","High (N+P)","Med (N+P)","Low (N+P)", "Baseline"),values = c("green4", brewer.pal(9, "Reds")[7],brewer.pal(9, "Reds")[6],brewer.pal(9, "Reds")[5],brewer.pal(9, "Blues")[7],brewer.pal(9, "Blues")[6],brewer.pal(9, "Blues")[5],brewer.pal(9, "Purples")[7],brewer.pal(9, "Purples")[6], brewer.pal(9, "Purples")[5], "grey"))+
  scale_linetype_manual(breaks=c(0,1), labels=c("Uninfected","Infected"), values=c(1,2))+
  scale_shape_manual(breaks=c(0,1), labels=c("Uninfected","Infected"), values=c(19,17))

size_plots = wrap_plots(plot_size_p,plot_size_n,plot_size_np, nrow = 1, ncol = 3)+ 
  plot_layout(guides = "collect")
size_plots