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## Author: Joshua M. Tebbs
## Date: 11 December 2011
## Update: 29 December 2017
## STAT 509 course notes: R Code
## Chapter 1
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# Example 1.1
# Page 3
# MATH 141 example
# Simulate data
x1 = runif(50,400,800) # SAT MATH
x2 = rnorm(50,3,0.3) # HS GPA
y = rnorm(50,75,10) # MATH 141 score

# The data in Example 1.1 are not real (I simulated them).
# You will get a different picture (than in the notes) if you run the code below.

# Produce 3d scatterplot (point cloud)
# Need to install (then load) scatterplot3d package in R
# Packages --> install; Packages --> load

scatterplot3d(x1,x2,y,
	highlight.3d=FALSE,axis=TRUE,col.grid="lightblue",xlab="SAT MATH",ylab="HS GPA",
	zlab="MATH 141 SCORE",main="",box=FALSE,pch=20)