little R script to plot the most comonly used focal lengths (the **/* globbing requires zsh)

focal_lengths.R

# exiftool -T -TAG -FocalLength -TAG -Model **/*.jpg > ~/all_focals2.txt

library(readr)
library(ggplot2)
library(dplyr)

focals <- 
  read_delim('~/all_focals2.txt', delim='\t', 
             col_names=c("1", "focal", "2", "model"),
             col_types=cols_only(focal = col_character(), model = col_character())) %>% 
  filter(!is.na(focal) && !is.na(model)) %>%
  filter(model == "NEX-3N")

focals$focal <- as.double(gsub(" mm$", "", focals$focal))
# focals$focal <- focals$focal - (focals$focal %% 10) # <--- for grouping focal lengths in intervals of 10
focals <- focals %>% filter(!is.na(focal))

ggplot(focals, aes(x=focal)) +
  geom_bar(width=0.7,aes(y=(..count..)/sum(..count..))) + 
  scale_x_continuous(breaks = seq(0, 250, by = 10)) +
  scale_y_continuous(labels = scales::percent) +
  labs(y="percent")