Plot dots + functions with R

library("ggplot2")
eq<-function(x){x*x}
tmp<-data.frame(x=data[,4],y=eq(data[,5]))

p<-qplot(x,y,data=tmp)

c<-stat_function(fun=eq)

print(p+c)

or

qplot(x, y, data=as.data.frame(curve(eq)), geom="line")

How to build bowtie2 index from genome

1. Download genome sequences (*fa) from NCBI;

2. cat *.fa > genome.fa

3. bowtie2-build genome.fa hg19 ##mm9 bm3

4. cp *.bt2 to bowtie2 index folder