CODEWITHSUNDEEP
rggplot2regressioncorrelation
Ana Raquel
Ana Raquel

Reputation: 155

R, R², p-value and regression equation

This code gives me a plot with the regression equation and R2: (but i need to mention in which x and y the equation will be (manually)

CORRELATIONP3 <-CORRELATIONP2[product=='a',]

x<-CORRELATIONP3$b
y<-CORRELATIONP3$p


df <- data.frame(x = x)
m <- lm(y ~ x, data = df)
p <- ggplot(data = df, aes(x = x, y = y)) +
  scale_x_continuous("b (%)") +
  scale_y_continuous("p (%)")+
  geom_smooth(method = "lm", formula = y ~ x) +
  geom_point()
p

eq <- substitute(italic(y) == a + b %.% italic(x)*","~~italic(r)^2~"="~r2,
             list(        a = format(coef(m)[1], digits = 4),
                          b = format(coef(m)[2], digits = 4),
                          r2 = format(summary(m)$r.squared, digits = 3)))

dftext <- data.frame(x = 3, y = 0.2, eq = as.character(as.expression(eq)))

p + geom_text(aes(label = eq), data = dftext, parse = TRUE)

equation and r square

But, with this code I have R and p-value: And here the information about R and p values fits automatically in the plot, why? I want this in the first one as well.

  CORRELATIONP3 <-CORRELATIONP2[product=='a',]

x<-CORRELATIONP3$b
y<-CORRELATIONP3$p


df <- data.frame(x = x)
m <- lm(y ~ x, data = df)
p <- ggplot(data = df, aes(x = x, y = y)) +
  scale_x_continuous("b (%)") +
  scale_y_continuous("p (%)")+
  geom_smooth(method = "lm", formula = y ~ x) +
  geom_point()
p

eq <- substitute(italic(r)~"="~rvalue*","~italic(p)~"="~pvalue, list(rvalue = sprintf("%.2f",sign(coef(m)[2])*sqrt(summary(m)$r.squared)), pvalue = format(summary(m)$coefficients[2,4], digits = 3)))


dftext <- data.frame(x = 30, y = 0.4, eq = as.character(as.expression(eq)))
p + geom_text(aes(label = eq), data = dftext, parse = TRUE)

R and p-value

Can you tell me how can I join all the 4 informations in one sigle plot? (R, R2, equation and p-value)

Besides that, i would like that these informations could be fitted automatically in the plot, not manually.

Upvotes: 0

Views: 2070

Answers (1)

Sarina
Sarina

Reputation: 558

Ok, I am not sure if this works as you have not given a reproducible example of your data but I guess you just have to rename one of your variables e.g.: 

eq2 <- substitute(italic(r)~"="~rvalue*","~italic(p)~"="~pvalue, 
list(rvalue = sprintf("%.2f",sign(coef(m)[2])*sqrt(summary(m)$r.squared)), 
pvalue = format(summary(m)$coefficients[2,4], digits = 3)))

and then you change the points you put it on in your plot just a bit below your other block in the first plot. x and y here refer to the position of the text lable so play around with these until your text looks ok.

dftext2 <- data.frame(x = 30, y = 0.12, eq2 = as.character(as.expression(eq2)))
p + geom_text(aes(label = eq2), data = dftext2, parse = TRUE)

please let me know if this works and if this is what you meant.

Upvotes: 1

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