ggplot2 graphing and plotting average and minimum - r

Question

here is my code:
library(dplyr); library(tidyr)
T0.modified <- T0data %>%
# create year range based on each company's T0 year
mutate(Year.M1 = Year - 1,
Year.M2 = Year - 2,
Year.M3 = Year - 3,
Year.P1 = Year + 1,
Year.P2 = Year + 2,
Year.P3 = Year + 3) %>%
# convert to long format, match with Alldata based on both company & year
gather(reference.year, actual.year, -Company, -Price) %>%
left_join(Alldata, by = c("Company" = "Company", "actual.year" = "Year")) %>%
# keep T0 price for year T0, & use matched prices for all other years
mutate(Price = ifelse(reference.year == "Year", Price.x, Price.y)) %>%
# take maximum of all matched prices for each company each year
group_by(Company, reference.year) %>%
summarise(Price = max(Price)) %>%
ungroup() %>%
# order reference.year for correct sequence in ggplot's x-axis
mutate(reference.year = factor(reference.year,
levels = c("Year.M3", "Year.M2", "Year.M1", "Year",
"Year.P1", "Year.P2", "Year.P3"),
labels = c("T-3", "T-2", "T-1", "T0", "T+1", "T+2", "T+3")))
ggplot(T0.modified,
aes(x = reference.year, y = Price, group = Company, color = Company)) +
geom_line(aes()) +
xlab("Year") + theme_bw() +
stat_summary(fun.y = mean, geom = "line", group = 1,
linetype = 2, size = 1.5, colour = "grey") +
annotate("label", x = 7, y = 200, label = "Average",
fill = "grey", alpha = 0.5, hjust = 1)
And here is my data:
T0data:
structure(list(Company = structure(1:3, .Label = c("Amazon",
"Cisco", "McDonald's"), class = "factor"), Year = c(2011L, 2008L,
2013L), Price = c(182, 21.82, 95.15)), .Names = c("Company",
"Year", "Price"), row.names = c(NA, 3L), class = "data.frame")
All Data:
structure(list(Company = structure(c(1L, 1L, 1L, 1L, 1L, 1L,
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 3L, 3L, 3L, 3L,
3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 2L, 2L,
2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L
), .Label = c("Amazon", "Cisco", "McDonald's"), class = "factor"),
Year = c(2008L, 2008L, 2008L, 2008L, 2009L, 2009L, 2010L,
2010L, 2010L, 2011L, 2011L, 2012L, 2012L, 2013L, 2013L, 2014L,
2014L, 2014L, 2008L, 2010L, 2010L, 2010L, 2011L, 2011L, 2012L,
2012L, 2013L, 2013L, 2014L, 2014L, 2014L, 2015L, 2015L, 2016L,
2016L, 2016L, 2005L, 2005L, 2005L, 2006L, 2006L, 2007L, 2007L,
2007L, 2008L, 2008L, 2009L, 2009L, 2009L, 2010L, 2010L, 2011L,
2011L, 2011L), Price = c(91L, 77L, 81L, 87L, 63L, 88L, 110L,
75L, 117L, 170L, 190L, 215L, 245L, 316L, 275L, 330L, 378L,
390L, 55L, 62L, 66L, 65L, 72L, 98L, 93L, 88L, 99L, 101L,
94L, 103L, 96L, 99L, 116L, 112L, 123L, 113L, 19L, 17L, 18L,
20L, 19L, 26L, 31L, 27L, 24L, 21L, 14L, 22L, 18L, 26L, 22L,
14L, 16L, 15L)), .Names = c("Company", "Year", "Price"), class = "data.frame", row.names = c(NA,
-54L))
Here's my question:
How can I make the line graph show only 2 values, the average, and the minimum for all values?
And How can I plot a random company to represent the third line in the graph too to compare it to the minimum and the average?

Answer 1

Something like this? It plots the average, the minimum and a random company (see subset).
p = ggplot(T0.modified) + xlab("Year") + theme_bw() +
stat_summary(aes(x = reference.year, y = Price),fun.y = mean, geom = "line", group = 1, linetype = 2, size = 1.5, colour = "grey") +
stat_summary(aes(x = reference.year, y = Price),fun.y = min, geom = "line", group = 1, linetype = 2, size = 1.5, colour = "red") +
annotate("label", x = 7, y = 200, label = "Average", fill = "grey", alpha = 0.5, hjust = 1) +
annotate("label", x = 7, y = 30, label = "Min", fill = "grey", alpha = 0.5, hjust = 1) +
geom_line(data = subset(T0.modified,Company=="Amazon"),aes(x = reference.year, y = Price,group=Company),color="blue")