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Examples: Poission distribution as applied to the 100-year flood. https://tonyladson.wordpress.com/2015/06/29/100-year-flood-poisson-distribution/
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dpois(0,1) # prob of zero 100-year floods in 100 years | |
dpois(0,1) # prob of zero 100-year floods in 100 years | |
[1] 0.3678794 | |
dpois(1,1) # prob of one 100-year floods in 100 years | |
[1] 0.3678794 | |
dpois(2,1) # prob of two 100-year floods in 100 years | |
[1] 0.1839397 | |
# simulation | |
library(ggplot2) | |
df <- expand.grid(x = 1:10, y = 1:10) | |
df$z <- rbinom(100, 100, 0.01) # could also use rpois(100,1) | |
ggplot(data=df, aes(x,y)) + geom_tile(aes(fill=z)) + | |
scale_fill_gradient(low="green", high = "red", name = 'Floods') + | |
geom_text(data = df, aes(x, y, label = z)) + | |
scale_x_continuous(breaks = NULL) + | |
scale_y_continuous(breaks = NULL) + | |
xlab('') + | |
ylab('') | |
set.seed(2000) | |
rpois(10, 1) | |
[1] 0 1 0 1 2 1 3 1 2 1 | |
# number of 100-year floods in each of 10 100-year sequences |
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