expReg: Exponential regression with plotting

In berryFunctions: Function Collection Related to Plotting and Hydrology

Exponential regression with plotting

Description

uses lm; plots data if add=FALSE, draws the regression line with abline and confidence interval with polygon and writes the formula with legend

Usage

expReg(
  x,
  y = NULL,
  data = NULL,
  logy = TRUE,
  predictnew = NULL,
  interval = "confidence",
  plot = TRUE,
  digits = 2,
  inset = 0,
  xpd = par("xpd"),
  pos1 = "top",
  pos2 = NULL,
  add = FALSE,
  pch = 16,
  col = rgb(0, 0, 0, 0.5),
  modcol = 2,
  lwd = 1,
  xlab = deparse(substitute(x)),
  ylab = deparse(substitute(y)),
  main = "exponential regression",
  xlim = range(x),
  ylim = range(y),
  ...
)

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
logy	Plot with a logarithmic y axis? Calls logAxis. DEFAULT: TRUE
predictnew	Vector with values to predict outcome for. Passed as newdata to predict.lm. DEFAULT: NULL
interval	Interval for prediction. DEFAULT: "confidence"
plot	Plot things at all? If FALSE, predictnew will still be returned. DEFAULT: TRUE
digits	Numeric vector of length \ge 1. Specifies number of digits a,b,r,e are rounded to in the formula "y=a*log(x)+b, R^2, RMSE=e", respectively. If values are not specified, they are set equal to the first. DEFAULT: 2
inset	Numeric vector of length \le 2. inset distance(s) from the margins as a fraction of the plot region when formula is placed by keyword. DEFAULT: 0
xpd	Logical, specifying 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: par("xpd")
pos1	xy.coords-acceptable position of the formula. DEFAULT: "top"
pos2	For numerical coordinates, this is the y-position. DEFAULT: NULL, as in legend
add	Logical. If TRUE, line and text are added to the existing graphic. DEFAULT: FALSE (plots datapoints first and then the line.)
pch	Point Character, see par. DEFAULT: 16
col	Color of points, see par. DEFAULT: rgb(0,0,0, 0.5)
modcol	color of model line. DEFAULT: 2
lwd	Numeric. Linewidth, see par. DEFAULT: 1
xlab, ylab, main	Character / Expression. axis label and graph title if add=FALSE. DEFAULT: internal from names
xlim, ylim	graphic range. DEFAULT: range(x)
...	Further arguments passed to plot and abline.

Value

predict.lm result.

Author(s)

Berry Boessenkool, [e-mail], Dec. 2014

See Also

lm, mReg, linReg.

Examples

x <- runif(100, 1, 10)
y <- 10^(0.3*x+rnorm(100, sd=0.3)+4)
plot(x,y)
expReg(x,y)
expReg(x,y, logy=FALSE)
expReg(x,y, predictnew=6, plot=FALSE)
expReg(x,y, predictnew=3:6, interval="none", plot=FALSE)

berryFunctions documentation built on May 29, 2024, 4:01 a.m.