r - ggplot2: plot 2 variables (lines and points) and align 2 plots -

i have started using ggplot2 finding lot of difficulties... @ moment want plot 2 different variables 1 plot points , lines (type=both in plot function), , have resulting plot placed , aligned above histogram sharing same x axis.

so have data.frame:

go.df <- data.frame(go.id=paste("go",c(1:29),sep=""),                     occ=c(1:29),                     pv=c(5.379594e-05, 3.052953e-03, 3.052953e-03, 3.052953e-03, 3.052953e-03, 3.052953e-03, 3.052953e-03, 3.052953e-03, 6.096906e-03, 6.096906e-03, 6.096906e-03, 6.096906e-03, 9.131884e-03, 9.131884e-03, 9.131884e-03, 9.131884e-03, 9.131884e-03, 9.131884e-03, 9.131884e-03, 1.215791e-02, 1.215791e-02, 1.215791e-02, 1.517502e-02, 1.517502e-02, 1.517502e-02, 1.517502e-02, 1.818323e-02, 1.818323e-02, 1.818323e-02),                     adj.pv=c(0.004088492, 0.029003053, 0.029003053, 0.029003053, 0.029003053, 0.029003053, 0.029003053, 0.029003053, 0.036527537, 0.036527537, 0.036527537, 0.036527537, 0.036527537, 0.036527537, 0.036527537, 0.036527537, 0.036527537, 0.036527537, 0.036527537, 0.042000065, 0.042000065, 0.042000065, 0.044357749, 0.044357749, 0.044357749, 0.044357749, 0.047652596, 0.047652596, 0.047652596)) 

and want reproduce this:

plot(go.df$pv, type="b", col="red", ylim=c(0,0.05),ylab="",xlab="",xaxt="n") lines(go.df$adj.pv, type="b", col="blue") axis(1, at=c(1:length(go.df$go.id)), labels=go.df$go.id, las=2) 

above histogram (of variable "occ") , aligned it. have far ggplot2:

#install.packages("ggplot2") library(ggplot2) #install.packages("reshape") library(reshape) #install.packages("gridextra") library(gridextra)  go.df2 <- melt(go.df, measure.vars=c("pv", "adj.pv")) p1 <- ggplot(go.df2, aes(x=go.id, y=value, colour=variable)) + geom_point() + ylab("p-values") + xlab(null) p2 <- ggplot(go.df2, aes(x=go.id, y=occ)) + geom_bar(stat="identity") + ylab("num of ocurrences") grid.arrange(   p1,    p2,   nrow = 2,   main = textgrob("go!", vjust = 1, gp=gpar(fontface = "bold", cex = 1.5))) 

as can see unable to:

1-plot both lines , points

2-have data not scattered around, ordered instead should (the order maintained plot function) in both plots.

3-have 2 plots aligned minimal distance between them , no x axis in 1 above.

4-have plots aligned still maintain legend of 1 above.

i hope me this, i'm still new ggplots2. lot!

i not use grid.arrange, rather more this:

    dat <- rbind(go.df2,go.df2)     dat$grp <- factor(rep(c('p-values','num of ocurrences'),each = nrow(go.df2)),                       levels = c('p-values','num of ocurrences'))     dat$go.id <- factor(dat$go.id,levels = unique(dat$go.id))  ggplot(dat,aes(x = go.id)) +      facet_grid(grp~.,scales = "free_y") +     geom_point(data = subset(dat,grp == 'p-values'),                aes(y = value,colour = variable)) +      geom_line(data = subset(dat,grp == 'p-values'),               aes(y = value,colour = variable,group = variable)) +      geom_bar(data = subset(dat,grp == 'num of ocurrences'),              aes(y = occ),stat = "identity") +      theme(axis.text.x = element_text(angle = 90, hjust = 1)) +     ylab("") 

plotting lines required adding geom_line, , making sure grouping set correctly.

ordering x axis, else in ggplot, requires creating factor , ordering levels properly.

aligning plots admittedly bit trickier. helps try massage faceting of aligning you. end, rbinded 2 copies of data together, , created grouping variable stand in different y axis labels.

then can use facet_grid force facet strips on y axis, allow free y scales, , pass appropriate subset of data each geom.

thanks agstudy, reminding me rotate x axis labels using theme.