On this Picostat.com statistics page, you will find information about the seedrates data set which pertains to Barley Seeding Rate Data. The seedrates data set is found in the DAAG R package. You can load the seedrates data set in R by issuing the following command at the console data("seedrates"). This will load the data into a variable called seedrates. If R says the seedrates data set is not found, you can try installing the package by issuing this command install.packages("DAAG") and then attempt to reload the data. If you need to download R, you can go to the R project website. You can download a CSV (comma separated values) version of the seedrates R data set. The size of this file is about 58 bytes.

Barley Seeding Rate Data

Description

The seedrates data frame has 5 rows and 2 columns on the effect of seeding rate of barley on yield.

Usage

seedrates

Format

This data frame contains the following columns:

rate

the seeding rate

grain

the number of grain per head of barley

Source

McLeod, C.C. 1982. Effect of rates of seeding on barley grown for grain. New Zealand Journal of Agriculture 10: 133-136.

References

Maindonald J H 1992. Statistical design, analysis and presentation issues. New Zealand Journal of Agricultural Research 35: 121-141.

Examples

plot(grain~rate,data=seedrates,xlim=c(50,180),ylim=c(15.5,22),axes=FALSE)
new.df<-data.frame(rate=(2:8)*25)
seedrates.lm1<-lm(grain~rate,data=seedrates)
seedrates.lm2<-lm(grain~rate+I(rate^2),data=seedrates)
hat1<-predict(seedrates.lm1,newdata=new.df,interval="confidence")
hat2<-predict(seedrates.lm2,newdata=new.df,interval="confidence")
axis(1,at=new.df$rate); axis(2); box()
z1<-spline(new.df$rate, hat1[,"fit"]); z2<-spline(new.df$rate,   
hat2[,"fit"])
rate<-new.df$rate; lines(z1$x,z1$y)
lines(spline(rate,hat1[,"lwr"]),lty=1,col=3)
lines(spline(rate,hat1[,"upr"]),lty=1,col=3)
lines(z2$x,z2$y,lty=4)
lines(spline(rate,hat2[,"lwr"]),lty=4,col=3)
lines(spline(rate,hat2[,"upr"]),lty=4,col=3)

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Dataset imported from https://www.r-project.org.