linReg {berryFunctions}  R Documentation 
linear regression with plotting
Description
uses lm
; plots data if add=FALSE, draws the regression line
with abline
and writes the formula with legend
Usage
linReg(
x,
y = NULL,
data = NULL,
add = FALSE,
digits = 2,
quiet = FALSE,
pch = 16,
col = "black",
colline = "red",
colband = addAlpha(colline),
level = 0.95,
plotrange = par("usr")[1:2],
lwd = 1,
xlab = deparse(substitute(x)),
ylab = deparse(substitute(y)),
main = "linear regression",
pos1 = "top",
pos2 = NULL,
inset = 0,
legargs = NULL,
...
)
Arguments
x 
Numeric or formula (see examples). Vector with values of explanatory variable 
y 
Numeric. Vector with values of dependent variable. DEFAULT: NULL 
data 
Dataframe. If x is a formula, the according columns from data are used as x and y. DEFAULT: NULL 
add 
Logical. If TRUE, line and text are added to the existing graphic. DEFAULT: FALSE (plots datapoints first and then the line.) 
digits 
Numeric vector of length 
quiet 
Silence NAremoval warnings in 
pch 
Point Character of datapoints, see 
col 
Color of points. DEFAULT: "black" 
colline 
Color of the regression line, see 
colband 
Color of the confidence region band. DEFAULT: addAlpha(col) 
level 
Confidence level, see 
plotrange 
x range for which regression line and uncertainty band should
be plotted. Is passed to 
lwd 
Numeric. Linewidth, see 
xlab 
Axis label if add=FALSE. DEFAULT: deparse(substitute(x)) 
ylab 
Axis label if add=FALSE. DEFAULT: deparse(substitute(y)) 
main 
Title if add=FALSE. Changed (if not specified) for x=formula with data. DEFAULT: "linear regression" 
pos1 

pos2 
For numerical coordinates, this is the yposition. DEFAULT: NULL, as in 
inset 
Numeric vector of length 
legargs 
list of arguments passed to legend, like list(cex=0.8, xpd=TRUE, bg="white"), ... xpd specifies whether formula can be written only inside the plot region (when FALSE) or inside the figure region including mar (when TRUE) or in the entire device region including oma (when NA). DEFAULT: NULL 
... 
Further arguments passed to 
Value
None, used for plotting and drawing.
Author(s)
Berry Boessenkool, berryb@gmx.de, 20112012, 2015
See Also
lm
, mReg
, expReg
, legend
, par
, abline
.
Examples
a < 1:30
b < a/2.345+rnorm(30,0,3)
linReg(a,b)
linReg(a,b, ylab="Hallo", pch=1, colline=3, main="Regression by Berry")
linReg(a, b, pos1=15, pos2=0) # position of topleft corner of legend
linReg(a, b, pos1=NA) # to suppress legend
linReg(a, b, plotrange=5:20) # only for plotting, all data points are used!
linReg(a,b, digits=c(2,3,2,1) ) # Do not write RMSE into legend
# Formula specification:
linReg(b~a)
linReg(Fertility~Education, data=swiss, col="blue", colline="green")
# col is for points, colline + colband for regression line + conf.int.
# For more flexibility with the datapoints, plot first, then use linReg with add=TRUE:
plot(a,b, xlim=c(5,45))
linReg(a, b, pos1="bottomright", add=TRUE, inset=.1) # inset: distance from plot border
linReg(a, b, digits=c(7,4,3), add=TRUE, colline=3, lty=2, lwd=4, level=0.8)
linReg(a, b, pos1="topleft", inset=c(0.1, 0.3), legargs=list(xpd=TRUE), add=TRUE)