mod10.R

# Install ISwR if needed
if (!requireNamespace("ISwR", quietly = TRUE)) {
  install.packages("ISwR")
}

# Load package and dataset
library(ISwR)
data("cystfibr")

# Multiple linear regression
model <- lm(pemax ~ age + weight + bmp + fev1,
            data = cystfibr)

# Regression coefficients, intercept, and R-squared
summary(model)

## 
## Call:
## lm(formula = pemax ~ age + weight + bmp + fev1, data = cystfibr)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -42.521 -10.885   3.003  15.488  41.767 
## 
## Coefficients:
##             Estimate Std. Error t value Pr(>|t|)   
## (Intercept) 179.2957    61.8855   2.897  0.00891 **
## age          -3.4181     3.3086  -1.033  0.31389   
## weight        2.6882     1.1727   2.292  0.03287 * 
## bmp          -2.0657     0.8198  -2.520  0.02036 * 
## fev1          1.0882     0.5139   2.117  0.04695 * 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 23.4 on 20 degrees of freedom
## Multiple R-squared:  0.5918, Adjusted R-squared:  0.5101 
## F-statistic: 7.248 on 4 and 20 DF,  p-value: 0.0008891

# ANOVA table
anova(model)

## Analysis of Variance Table
## 
## Response: pemax
##           Df  Sum Sq Mean Sq F value    Pr(>F)    
## age        1 10098.5 10098.5 18.4385 0.0003538 ***
## weight     1   945.2   945.2  1.7258 0.2038195    
## bmp        1  2379.7  2379.7  4.3450 0.0501483 .  
## fev1       1  2455.6  2455.6  4.4836 0.0469468 *  
## Residuals 20 10953.7   547.7                      
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1