# Make response spectrum diagram (log-log)
plot(
    001,0.01,
    log="xy",
    type="n",
    xlim=c(0.01,10),
    ylim=c(10,10000),
    xlab="Period (sec)",
    ylab="Response acceleration (gal)",
    axes=FALSE
)
mtext(text=" h=0.05",side=3,line=0,adj=0)
cc<-seq(1,9,by=1)
c1<-c(cc*0.01,cc*0.1,cc,10)
c2<-c(cc*10,cc*100,cc*1000,10000)
abline(v=c1,col="gray")
abline(h=c2,col="gray")
axis(1,c(0.01,0.1,1,10)) 
axis(2,c(10,100,1000,10000)) 
box()
d1<-read.table("dat_spc_1.txt",skip=1)
d2<-read.table("dat_spc_2.txt",skip=1)
d3<-read.table("dat_spc_3.txt",skip=1)
lines(d1[,1],d1[,2],lwd=2,col="red")
lines(d2[,1],d2[,2],lwd=2,col="blue")
lines(d3[,1],d3[,2],lwd=2,col="green")
legend(
    "bottomleft",
    c("TCGH16_EW2","TCGH16_NS2","TCGH16_UD2"),
    col = c("blue","red","green"),
    lty = c(1,1,1),
    lwd = c(2,2,2),
    bg  = "white"
)