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rgraphicslinesgraphic

Error when plotting lines in R

I am trying to plot some lines on R, but it exchange the lines. Pehaps it is something I am doing wrong. If someone can help me with this.

The dataframes I have are:

df_sel2 <- read.table(text="knn_sel2 tam_tab
V11   3.500000       8
V12   3.740000      64
V13   7.111667     512
V14  25.361667    4096
V15 195.018333   32768", header=TRUE)
df_sel4 <- read.table(text="knn_sel4 tam_tab
V11   3.535000       8
V12   3.811667      64
V13   7.193333     512
V14  26.151667    4096
V15 203.636667   32768", header=TRUE)
df_sel8 <- read.table(text="knn_sel8 tam_tab
V11   3.961667       8
V12   4.055000      64
V13   7.538333     512
V14  27.288333    4096
V15 209.646667   32768", header=TRUE)
df_sel32 <- read.table(text="knn_sel32 tam_tab
V11   3.750000       8
V12   5.040000      64
V13   8.581667     512
V14  30.103333    4096
V15 225.441667   32768", header=TRUE)

The graph is being plot through this code:

qplot(tam_tab,knn_sel2,data=df_sel2, linetype="2",geom="line") +
  geom_line(mapping=aes(tam_tab,knn_sel4,linetype="4"),data=df_sel4) + 
  geom_line(mapping=aes(tam_tab,knn_sel8,linetype="8"),data=df_sel8) +
  geom_line(mapping=aes(tam_tab,knn_sel32,linetype="32"),data=df_sel32) + 
  scale_linetype_manual("Valor da Seletividade", 
             values=c("solid","dotted","dashed","dotdash"),
             labels=c("2","4", "8","32")) + 
  labs( x ="Tamanho da tabela interna", y = "tempo (s)")

The result I get is this:

enter image description here

As can be seen, the label "4" is in the place of the "32". Why is it happening?

Thanks in advance!

Solution

  • The problem is with your labels= arguemnt. This is for renaming the levels. I fyou want to specify the order, you need to specify the breaks=. Use

    scale_linetype_manual("Valor da Seletividade", 
         values=c("solid","dotted","dashed","dotdash"),
         breaks=c("2","4", "8","32"))

    Of course, the more friendly way to do this with ggplot is to merge all your data into one data frame. Here's one way to do that

    library(dplyr)
sels <- c(2,4,8,32)
mydata <- mget(paste0("df_sel", sels)) %>% 
    Map(data.frame, ., sel=sels) %>% 
    Map(function(x) setNames(x, c("knn","tam_tab", "sel")), .) %>% 
    bind_rows() %>%
    mutate(sel=factor(sel, sels))

    Then your plotting code becomes more simple

    ggplot(mydata, aes(tam_tab , knn, linetype=sel)) + geom_line()