Tabulate coefficients from lm

Question

I have 10 linear models where I only need some information, namely: r-squared, p-value, coefficients of slope and intercept. I managed to extract these values (via ridiculously repeating the code). Now, I need to tabulate these values (Info in the columns; the rows listing results from linear models 1-10). Can anyone please help me? I have hundreds more linear models to do. I'm sure there must be a way.

Data file hosted here

Code:

d<-read.csv("example.csv",header=T)

# Subset data
A3G1 <- subset(d, CatChro=="A3G1"); A4G1 <- subset(d, CatChro=="A4G1")
A3G2 <- subset(d, CatChro=="A3G2"); A4G2 <- subset(d, CatChro=="A4G2")
A3G3 <- subset(d, CatChro=="A3G3"); A4G3 <- subset(d, CatChro=="A4G3")
A3G4 <- subset(d, CatChro=="A3G4"); A4G4 <- subset(d, CatChro=="A4G4")
A3G5 <- subset(d, CatChro=="A3G5"); A4G5 <- subset(d, CatChro=="A4G5")
A3D1 <- subset(d, CatChro=="A3D1"); A4D1 <- subset(d, CatChro=="A4D1")
A3D2 <- subset(d, CatChro=="A3D2"); A4D2 <- subset(d, CatChro=="A4D2")
A3D3 <- subset(d, CatChro=="A3D3"); A4D3 <- subset(d, CatChro=="A4D3")
A3D4 <- subset(d, CatChro=="A3D4"); A4D4 <- subset(d, CatChro=="A4D4")
A3D5 <- subset(d, CatChro=="A3D5"); A4D5 <- subset(d, CatChro=="A4D5")

# Fit individual lines
rA3G1 <- lm(Qend~Rainfall, data=A3G1); summary(rA3G1)
rA3D1 <- lm(Qend~Rainfall, data=A3D1); summary(rA3D1)
rA3G2 <- lm(Qend~Rainfall, data=A3G2); summary(rA3G2)
rA3D2 <- lm(Qend~Rainfall, data=A3D2); summary(rA3D2)
rA3G3 <- lm(Qend~Rainfall, data=A3G3); summary(rA3G3)
rA3D3 <- lm(Qend~Rainfall, data=A3D3); summary(rA3D3)
rA3G4 <- lm(Qend~Rainfall, data=A3G4); summary(rA3G4)
rA3D4 <- lm(Qend~Rainfall, data=A3D4); summary(rA3D4)
rA3G5 <- lm(Qend~Rainfall, data=A3G5); summary(rA3G5)
rA3D5 <- lm(Qend~Rainfall, data=A3D5); summary(rA3D5)

rA4G1   <- lm(Qend~Rainfall, data=A4G1); summary(rA4G1)
rA4D1   <- lm(Qend~Rainfall, data=A4D1); summary(rA4D1)
rA4G2   <- lm(Qend~Rainfall, data=A4G2); summary(rA4G2)
rA4D2   <- lm(Qend~Rainfall, data=A4D2); summary(rA4D2)
rA4G3   <- lm(Qend~Rainfall, data=A4G3); summary(rA4G3)
rA4D3   <- lm(Qend~Rainfall, data=A4D3); summary(rA4D3)
rA4G4   <- lm(Qend~Rainfall, data=A4G4); summary(rA4G4)
rA4D4   <- lm(Qend~Rainfall, data=A4D4); summary(rA4D4)
rA4G5   <- lm(Qend~Rainfall, data=A4G5); summary(rA4G5)
rA4D5   <- lm(Qend~Rainfall, data=A4D5); summary(rA4D5)

# Gradient
summary(rA3G1)$coefficients[2,1]
summary(rA3D1)$coefficients[2,1]
summary(rA3G2)$coefficients[2,1]
summary(rA3D2)$coefficients[2,1] 
summary(rA3G3)$coefficients[2,1] 
summary(rA3D3)$coefficients[2,1] 
summary(rA3G4)$coefficients[2,1] 
summary(rA3D4)$coefficients[2,1] 
summary(rA3G5)$coefficients[2,1] 
summary(rA3D5)$coefficients[2,1]

# Intercept
summary(rA3G1)$coefficients[2,2] 
summary(rA3D1)$coefficients[2,2] 
summary(rA3G2)$coefficients[2,2] 
summary(rA3D2)$coefficients[2,2] 
summary(rA3G3)$coefficients[2,2] 
summary(rA3D3)$coefficients[2,2] 
summary(rA3G4)$coefficients[2,2] 
summary(rA3D4)$coefficients[2,2] 
summary(rA3G5)$coefficients[2,2] 
summary(rA3D5)$coefficients[2,2] 

# r-sq
summary(rA3G1)$r.squared
summary(rA3D1)$r.squared
summary(rA3G2)$r.squared
summary(rA3D2)$r.squared
summary(rA3G3)$r.squared
summary(rA3D3)$r.squared
summary(rA3G4)$r.squared
summary(rA3D4)$r.squared
summary(rA3G5)$r.squared
summary(rA3D5)$r.squared

# adj r-sq
summary(rA3G1)$adj.r.squared
summary(rA3D1)$adj.r.squared
summary(rA3G2)$adj.r.squared
summary(rA3D2)$adj.r.squared
summary(rA3G3)$adj.r.squared
summary(rA3D3)$adj.r.squared
summary(rA3G4)$adj.r.squared
summary(rA3D4)$adj.r.squared
summary(rA3G5)$adj.r.squared
summary(rA3D5)$adj.r.squared

# p-level
p <- summary(rA3G1)$fstatistic
pf(p[1], p[2], p[3], lower.tail=FALSE) 
p2 <- summary(rA3D1)$fstatistic
pf(p2[1], p2[2], p2[3], lower.tail=FALSE) 
p3 <- summary(rA3G2)$fstatistic
pf(p3[1], p3[2], p3[3], lower.tail=FALSE) 
p4 <- summary(rA3D2)$fstatistic
pf(p4[1], p4[2], p4[3], lower.tail=FALSE) 
p5 <- summary(rA3G3)$fstatistic
pf(p5[1], p5[2], p5[3], lower.tail=FALSE) 
p6 <- summary(rA3D3)$fstatistic
pf(p6[1], p6[2], p6[3], lower.tail=FALSE) 
p7 <- summary(rA3G4)$fstatistic
pf(p7[1], p7[2], p7[3], lower.tail=FALSE) 
p8 <- summary(rA3D4)$fstatistic
pf(p8[1], p8[2], p8[3], lower.tail=FALSE) 
p9 <- summary(rA3G5)$fstatistic
pf(p9[1], p9[2], p9[3], lower.tail=FALSE) 
p10 <- summary(rA3D5)$fstatistic
pf(p10[1], p10[2], p10[3], lower.tail=FALSE) 

This is the structure of my expected outcome:

Is there any way to achieve this?

Answer 1

Here is a base R solution:

data <- read.csv("./data/so53933238.csv",header=TRUE)

# split by value of CatChro into a list of datasets
dataList <- split(data,data$CatChro)

# process the list with lm(), extract results to a data frame, write to a list
lmResults <- lapply(dataList,function(x){
     y <- summary(lm(Qend ~ Rainfall,data = x))
     Intercept <- y$coefficients[1,1]
     Slope <- y$coefficients[2,1]
     rSquared <- y$r.squared
     adjRSquared <- y$adj.r.squared
     f <- y$fstatistic[1]
     pValue <- pf(y$fstatistic[1],y$fstatistic[2],y$fstatistic[3],lower.tail = FALSE)
     data.frame(Slope,Intercept,rSquared,adjRSquared,pValue)
})
lmResultTable <- do.call(rbind,lmResults)
# add CatChro indicators
lmResultTable$catChro <- names(dataList)

lmResultTable 

...and the output:

    > lmResultTable
            Slope   Intercept   rSquared  adjRSquared       pValue catChro
A3D1 0.0004085644 0.011876543 0.28069553  0.254054622 0.0031181110    A3D1
A3D2 0.0005431693 0.023601325 0.03384173  0.005425311 0.2828170556    A3D2
A3D3 0.0001451185 0.022106960 0.04285322  0.002972105 0.3102578215    A3D3
A3D4 0.0006614213 0.009301843 0.37219027  0.349768492 0.0003442445    A3D4
A3D5 0.0001084626 0.014341399 0.04411669 -0.008987936 0.3741011769    A3D5
A3G1 0.0001147645 0.024432020 0.03627553  0.011564648 0.2329519751    A3G1
A3G2 0.0004583538 0.026079409 0.06449971  0.041112205 0.1045970987    A3G2
A3G3 0.0006964512 0.043537869 0.07587433  0.054383038 0.0670399684    A3G3
A3G4 0.0006442175 0.023706652 0.17337420  0.155404076 0.0032431299    A3G4
A3G5 0.0006658466 0.025994831 0.17227383  0.150491566 0.0077413595    A3G5
>

To render the output in a tabular format in HTML, one can use knitr::kable().

library(knitr)
kable(lmResultTable[1:5],row.names=TRUE,digits=5) 

...which produces the following output after rendering the Markdown: