r - Reorder geom_bar based on value-column -

i trying reorder bar_plot highest lowest value. wrong code?

 head(summary.m)    var1   var2 value 2   u-a length  1155 3  u-aa length   422 4 u-aaa length   119 5 u-aac length     6 6 u-aag length    19 7 u-aat length    49  ggplot(summary.m, aes(x=reorder(var1,-value),y=value)) + geom_bar(stat="identity") +   theme_bw(base_size=8) +   theme(axis.text.x = element_text(colour = "black",angle=90 )) 

you need specify function used in reorder. try this

ggplot(summary.m, aes(x=reorder(var1,value, fun=sum),y=value)) + geom_bar(stat="identity") +   theme_bw(base_size=8) +   theme(axis.text.x = element_text(colour = "black",angle=90 )) 

note : code works fine me, have inverted order.