r - Legend control with two data frames of different x-scales and different geoms in ggplot2 -

could explain me on how full control on legends in ggplot2 2 data frames different x-scales presented in 2 different geoms. 'name1' , 'name2' function created other filtering function.

1. why geom_point shape appears in legend "group 1"? expect legend show colour in group1 , shape group2.

is possible rearrange legends well? i.e group2 appears first in row.

df1 <- data.frame(g1 = c("a", "b", "c", "e"),                   y1 = c(12, 8, 3, 20)) df2 <- data.frame(g1 = letters[1:5],                   y1 = 20:24) name1 <- "group 1" name2 <- "group 2"  require(ggplot2) ggplot(null, aes(x=g1, y=y1)) +     geom_bar(data = df1, stat = "identity",              aes(fill=factor(name1))) +     geom_point(data = df2, stat = "identity",                size = 5, shape = 2, aes(fill=factor(name2))) +     theme(plot.margin = unit(c(2,1,1,1), "lines"),                      plot.title = element_text(hjust = 0, size=18),                      axis.title = element_text(face = "bold", size = 12),                      legend.position = 'top',                      legend.text = element_text(size = 12),                      legend.title = element_blank()) 

the key define fill , shape in both aes(). can define shape , fill na 1 don't need.

ggplot(null, aes(x=g1, y=y1)) +   geom_bar(data = df1, stat = "identity", aes(fill=name2, shape=name2)) +   geom_point(data = df2, size = 5, aes(shape=name1, fill=name1)) +   theme(plot.margin = unit(c(2,1,1,1), "lines"),         plot.title = element_text(hjust = 0, size=18),         axis.title = element_text(face = "bold", size = 12),         legend.position = 'top',         legend.text = element_text(size = 12),         legend.title = element_blank()) +   scale_shape_manual(values=c(2, na)) +   scale_fill_manual(values=c(na, "red")) +   guides(fill = guide_legend(reverse = true),          shape = guide_legend(reverse = true))