R Notes - Revision history

Sperry at 17:38, 13 June 2008

2008-06-13T17:38:55Z

2008-06-13T17:35:45Z

2008-06-13T17:35:16Z

2008-06-13T17:24:36Z

2008-06-13T17:23:18Z

2008-06-13T17:20:55Z

2008-06-13T17:20:05Z

2008-06-13T17:00:45Z

2008-06-13T16:57:10Z

2008-06-13T16:54:12Z

@@ Line 35: / Line 35: @@
 * Launch R, and then paste this into the shell:
     # Scott's quick R example
-    par (mfrow=c(2,2), oma = c(0, 0, 2, 0), mar = c(5.1, 4.1, 2.1, 2.1), pch=20 ); <br />
+    par (mfrow=c(2,2), oma = c(0, 0, 2, 0), mar = c(5.1, 4.1, 2.1, 2.1)); <br />
     a = rnorm(1000)
     b = rnorm(1000)

@@ Line 7: / Line 7: @@
 * You may then access each of the individual records using myvector[row, column]
 ** Access entire columns using myvector[,1], myvector[,2], ... myvector[,n]
-** Access entire rows using myvector[1,], myvector[2,], ... myvector[3,]
+** Access entire rows using myvector[1,], myvector[2,], ... myvector[n,]
 === Scatterplot two columns of a vector ===

@@ Line 5: / Line 5: @@
 === Loading a plain CSV file into a vector ===
     myvector = read.csv(file="path_to_csv_file", header=FALSE)
-* You may then access each of the individual components using myvector[,1], myvector[,2], ... myvector[,n]
+* You may then access each of the individual records using myvector[row, column]
-=== Scatterplot two components of a vector ===
+=== Scatterplot two columns of a vector ===
-In this example, myvector has 4 components and we want to plot the 3rd and 4th
+In this example, myvector has 4 columns and we want to plot the 3rd and 4th
     plot(myvector[,3], myvector[,4], main="This is the title of the plot")

@@ Line 36: / Line 36: @@
     a = rnorm(1000)
     b = rnorm(1000)
-    c = rnorm(20000)
+    c = rlnorm(20000)
     d = rnorm(20000, mean=5, sd=20) <br />
     plot(a, b, main = "A vs B", xlab="x axis", ylab="y axis", pch=20, col="blue")

@@ Line 36: / Line 36: @@
     a = rnorm(1000)
     b = rnorm(1000)
-    c = rnorm(10000)
+    c = rnorm(20000)
-    d = rnorm(10000, mean=5, sd=20) <br />
+    d = rnorm(20000, mean=5, sd=20) <br />
     plot(a, b, main = "A vs B", xlab="x axis", ylab="y axis", pch=20, col="blue")
-    plot(c, d, main = "C vs D", xlab="x axis", ylab="y axis", pch=".", col=palette(rainbow(100)))
+    plot(c, d, main = "C vs D", xlab="x axis", ylab="y axis", pch=".", col=palette(rainbow(50)))
     hist(a, main = "Histogram of A", col="darkgreen")
     plot(density(b), main = "Density plot of B", col="red") <br />
     mtext("This is an example that combines multiple plots on a single page", line=0.5, outer=TRUE)

@@ Line 13: / Line 13: @@
 === Plot a simple histogram ===
     hist(myvector[,3])
-* Also try ''density(myvector[,3])'' for a density-plot
+* Also try ''plot(density(myvector[,3]))'' for a density-plot
 === Linear regression ===
@@ Line 29: / Line 29: @@
 === For loops ===
     for (i in 1:100) { ''do_something_useful'' }

← Older revision		Revision as of 17:00, 13 June 2008
Line 1:		Line 1:
	== A few very basic R examples ==		== A few very basic R examples ==
		+
		+	__TOC__

	=== Loading a plain CSV file into a vector ===		=== Loading a plain CSV file into a vector ===

@@ Line 18: / Line 18: @@
 === Squeeze multiple plots onto a page ( 4x4 in this example ) ===
-    par(cfrow = c(4,4)) # or par(cfcol = c(4,4))
+    par(cfrow = c(4,4))
     plot(myvector[,3], myvector[,4])
     plot(myvector[,3], myvector[,4])

← Older revision		Revision as of 16:54, 13 June 2008
Line 16:		Line 16:
	mymodel = lm(myvector[,3] ~ myvector[,4])		mymodel = lm(myvector[,3] ~ myvector[,4])
	summary(mymodel)		summary(mymodel)
		+
		+	=== Squeeze multiple plots onto a page ( 4x4 in this example ) ===
		+	par(cfrow = c(4,4)) # or par(cfcol = c(4,4))
		+	plot(myvector[,3], myvector[,4])
		+	plot(myvector[,3], myvector[,4])
		+	plot(myvector[,3], myvector[,4])
		+	plot(myvector[,3], myvector[,4])
		+
		+	=== For loops ===
		+	for (i in 1:100) { ''do_something_useful'' }