[R]Regression Analysis

### lm function

tic <- Sys.time()

Data<-matrix(nrow=10,ncol=20,rnorm(1:200))

rownames(Data)<-paste("Gene", 1:10, sep = "")

test<-matrix(nrow=nrow(Data),ncol=ncol(Data)+1)

test[1,]<-rep(0,21)

for(i in 2:10){

out<-lm(Data[1,]~Data[i,])

test[i,1]<-out$coefficients[2]

test[i,-1]<-out$residuals

out<-c()

}

toc <- Sys.time()

comp.time <- toc - tic

### matrix calculate

tic <- Sys.time()

Data<-matrix(nrow=10,ncol=20,rnorm(1:200))

rownames(Data)<-paste("Gene", 1:10, sep = "")

test<-matrix(nrow=nrow(Data),ncol=ncol(Data)+1)

test[1,]<-rep(0,21)

y<-matrix(ncol=1,Data[1,])

for(i in 2:10){

x<-c()

out<-c()

x<-cbind(rep(1,20),Data[i,])

#求bo,b1

out<-solve(t(x)%*%x) %*% (t(x)%*%y)

test[i,1]<-out[2,]

#求residual

res<-c(y - (x%*%out))

sse<-sum(res^2)

}

toc <- Sys.time()

comp.time <- toc - tic