library(tidyverse)
url <- "https://raw.githubusercontent.com/jlacasa/stat705_fall2024/main/classes/data/lotus_part2.csv"
dd <- read.csv(url)
dd %>%
filter(species %in% c("A")) %>%
ggplot(aes(doy, crown_g))+
geom_point(aes(fill = trt), shape = 21, size =3.5)+
scale_fill_manual(values = c("#DB504A", "#43AA8B"))+
labs(x = "Day of the Year",
y = "Crown biomass (g)",
fill = "Treatment")+
theme_classic()+
theme(aspect.ratio = 1)
m <- lm(crown_g ~ trt + doy, data = dd)
summary(m)
Call:
lm(formula = crown_g ~ trt + doy, data = dd)
Residuals:
Min 1Q Median 3Q Max
-0.40020 -0.13449 -0.00894 0.09488 0.78319
Coefficients:
Estimate Std. Error t value Pr(>|t|)
(Intercept) -1.359492 0.137887 -9.859 1.6e-15 ***
trtflood -0.030954 0.043359 -0.714 0.477
doy 0.009197 0.000692 13.291 < 2e-16 ***
---
Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
Residual standard error: 0.1967 on 81 degrees of freedom
Multiple R-squared: 0.6861, Adjusted R-squared: 0.6784
F-statistic: 88.53 on 2 and 81 DF, p-value: < 2.2e-16m <- lm(crown_g ~ trt * doy, data = dd)
summary(m)
Call:
lm(formula = crown_g ~ trt * doy, data = dd)
Residuals:
Min 1Q Median 3Q Max
-0.35287 -0.13701 -0.01415 0.09433 0.73550
Coefficients:
Estimate Std. Error t value Pr(>|t|)
(Intercept) -1.5809069 0.1908532 -8.283 2.25e-12 ***
trtflood 0.4123418 0.2706453 1.524 0.132
doy 0.0103322 0.0009681 10.673 < 2e-16 ***
trtflood:doy -0.0022714 0.0013692 -1.659 0.101
---
Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
Residual standard error: 0.1946 on 80 degrees of freedom
Multiple R-squared: 0.6966, Adjusted R-squared: 0.6852
F-statistic: 61.21 on 3 and 80 DF, p-value: < 2.2e-16m <- lm(crown_g ~ trt * factor(doy), data = dd)
summary(m)
Call:
lm(formula = crown_g ~ trt * factor(doy), data = dd)
Residuals:
Min 1Q Median 3Q Max
-0.39578 -0.07140 -0.01645 0.07160 0.63792
Coefficients:
Estimate Std. Error t value Pr(>|t|)
(Intercept) 1.282e-01 5.038e-02 2.544 0.0129 *
trtflood 1.346e-16 7.125e-02 0.000 1.0000
factor(doy)194 1.928e-01 6.171e-02 3.124 0.0025 **
factor(doy)237 8.372e-01 7.125e-02 11.750 <2e-16 ***
trtflood:factor(doy)194 -1.594e-02 9.426e-02 -0.169 0.8662
trtflood:factor(doy)237 -1.806e-01 1.008e-01 -1.793 0.0769 .
---
Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
Residual standard error: 0.1745 on 78 degrees of freedom
Multiple R-squared: 0.7619, Adjusted R-squared: 0.7467
F-statistic: 49.92 on 5 and 78 DF, p-value: < 2.2e-16