head(iris)
## Sepal.Length Sepal.Width Petal.Length Petal.Width Species
## 1 5.1 3.5 1.4 0.2 setosa
## 2 4.9 3.0 1.4 0.2 setosa
## 3 4.7 3.2 1.3 0.2 setosa
## 4 4.6 3.1 1.5 0.2 setosa
## 5 5.0 3.6 1.4 0.2 setosa
## 6 5.4 3.9 1.7 0.4 setosa
# List of subsets
iris1 = split(iris, iris$Species)
# Function to apply on each subset
f = function(x) {
fit = lm(Petal.Width ~ Petal.Length + Sepal.Width + Sepal.Length, data = x)
summary(fit)
}
# Apply function
lapply(iris1, f)
## $setosa
##
## Call:
## lm(formula = Petal.Width ~ Petal.Length + Sepal.Width + Sepal.Length,
## data = x)
##
## Residuals:
## Min 1Q Median 3Q Max
## -0.17450 -0.05866 -0.03017 0.06594 0.32950
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) -0.29474 0.21717 -1.357 0.1813
## Petal.Length 0.16913 0.08560 1.976 0.0542 .
## Sepal.Width 0.01984 0.05642 0.352 0.7267
## Sepal.Length 0.04504 0.06196 0.727 0.4710
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 0.1002 on 46 degrees of freedom
## Multiple R-squared: 0.1509, Adjusted R-squared: 0.09556
## F-statistic: 2.726 on 3 and 46 DF, p-value: 0.05489
##
##
## $versicolor
##
## Call:
## lm(formula = Petal.Width ~ Petal.Length + Sepal.Width + Sepal.Length,
## data = x)
##
## Residuals:
## Min 1Q Median 3Q Max
## -0.271031 -0.066139 0.002672 0.063371 0.246702
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) -0.16864 0.18946 -0.890 0.378043
## Petal.Length 0.30875 0.05350 5.771 6.37e-07 ***
## Sepal.Width 0.22328 0.06187 3.609 0.000756 ***
## Sepal.Length -0.07398 0.04742 -1.560 0.125599
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 0.1105 on 46 degrees of freedom
## Multiple R-squared: 0.7069, Adjusted R-squared: 0.6878
## F-statistic: 36.98 on 3 and 46 DF, p-value: 2.571e-12
##
##
## $virginica
##
## Call:
## lm(formula = Petal.Width ~ Petal.Length + Sepal.Width + Sepal.Length,
## data = x)
##
## Residuals:
## Min 1Q Median 3Q Max
## -0.51430 -0.17403 0.00328 0.16883 0.44503
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) 0.50026 0.39454 1.268 0.211192
## Petal.Length 0.14968 0.12084 1.239 0.221751
## Sepal.Width 0.43869 0.11698 3.750 0.000493 ***
## Sepal.Length -0.09258 0.10803 -0.857 0.395875
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 0.2348 on 46 degrees of freedom
## Multiple R-squared: 0.3136, Adjusted R-squared: 0.2689
## F-statistic: 7.006 on 3 and 46 DF, p-value: 0.00056