stat_eq: Add Equation to 'ggplot'

In ggtrendline: Add Trendline and Confidence Interval to 'ggplot'

Add Equation to 'ggplot'

Description

Add regression equation to 'ggplot', by using different models built in the 'ggtrendline()' function. The function includes the following models:
"line2P" (formula as: y=a*x+b),
"line3P" (y=a*x^2+b*x+c),
"log2P" (y=a*ln(x)+b),
"exp2P" (y=a*exp(b*x)),
"exp3P" (y=a*exp(b*x)+c),
"power2P" (y=a*x^b),
and "power3P" (y=a*x^b+c).

Usage

stat_eq(
  x,
  y,
  model = "line2P",
  show.eq = TRUE,
  xname = "x",
  yname = "y",
  yhat = FALSE,
  eq.x = NULL,
  eq.y = NULL,
  text.col = "black",
  eDigit = 3,
  eSize = 3
)

Arguments

x, y	the x and y arguments provide the x and y coordinates for the 'ggplot'. Any reasonable way of defining the coordinates is acceptable.
model	select which model to fit. Default is "line2P". The "model" should be one of c("line2P", "line3P", "log2P", "exp2P", "exp3P", "power2P", "power3P"), their formulas are as follows: "line2P": y=a*x+b "line3P": y=a*x^2+b*x+c "log2P": y=a*ln(x)+b "exp2P": y=a*exp(b*x) "exp3P": y=a*exp(b*x)+c "power2P": y=a*x^b "power3P": y=a*x^b+c
show.eq	whether to show the regression equation, the value is one of c("TRUE", "FALSE").
xname	to specify the expression of "x" in equation, i.e., expression('x'), see Examples.
yname	to specify the expression of "y" in equation, i.e., expression('y'), see Examples.
yhat	whether to add a hat symbol (^) on the top of "y" in equation. Default is FALSE.
eq.x, eq.y	equation position.
text.col	the color used for the equation text.
eDigit	the numbers of digits for equation parameters. Default is 3.
eSize	font size of equation. Default is 3.

Details

The values of each parameter of regression model can be found by typing trendline_sum function in this package.

The linear models (line2P, line3P, log2P) in this package are estimated by lm function, while the nonlinear models (exp2P, exp3P, power2P, power3P) are estimated by nls function (i.e., least-squares method).

Value

No return value (called for side effects).

See Also

ggtrendline, stat_rrp, trendline_sum

ggtrendline documentation built on April 27, 2022, 9:06 a.m.