ggplot中的方面在变量图中放置错误的观察值

Question

I'm trying to plot a graph using the Facets feature from ggplot2 from a simple data.frame extracted from the Lahman package. Nevertheless, it's placing some observations in the wrong variable plot. I've tried to use several configurations in the facet_grid arguments but all of them have wrong placement of the observations.

Here below the code to reproduce the plot.

library(Lahman)
library(tidyverse)
library(plotly)

TmsStd <- Teams

TmsStd <- TmsStd %>% select(yearID, lgID, teamID, divID, Rank, W, L, DivWin, WCWin, LgWin, WSWin, name, teamIDBR)

TmsStd$WLPctg <- TmsStd$W / (TmsStd$W + TmsStd$L)

TmsStd <- TmsStd %>% arrange(yearID, desc(WLPctg))

TmsStd$OvSeaRank <- ave(TmsStd$WLPctg, TmsStd$yearID, FUN = seq_along)

TmPostS <- TmsStd %>% filter(OvSeaRank <= 4 & WSWin == "Y" & yearID > 1970) %>% select(yearID, teamIDBR, W, L, WLPctg, OvSeaRank)

Best_Post <- ggplot(data = TmPostS, aes(x = yearID)) +
  geom_bar() + 
  ggtitle("ABC") +
  xlab("Year") + ylab("") +
  facet_grid(OvSeaRank ~ .) +
  theme_light()

Best_Post

facet_grid plot

There is only one observation per year.

table(TmPostS$yearID)

1971 1972 1973 1974 1975 1976 1977 1978 1979 1981 1982 1983 1984 1986 1988 1989 1990 1991 1992 1993 1995 1996 
   1    1    1    1    1    1    1    1    1    1    1    1    1    1    1    1    1    1    1    1    1    1 
1997 1998 1999 2002 2004 2005 2007 2009 2013 2015 
   1    1    1    1    1    1    1    1    1    1 

So it must exist only one line per year independently of the "OvSeaRank" variable.

Any hint of what I could be doing wrong?

Thanks in advance.

Answer 1

By default geom_bar will count the number of occurrences of each year (which is always 1) rather than the value. You need to change the default behaviour with stat="identity" so it uses the column value.

ggplot(TmPostS, aes(x = yearID, y=OvSeaRank)) + geom_bar(stat="identity") + 
ggtitle("ABC") + xlab("Year") + ylab("") + facet_grid(OvSeaRank ~ .) +
theme_light()

It's actually better without faceting, because you don't really have enough variables in the plot. Leaving out facet_grid(OvSeaRank ~ .) gives the following:

Idea How about using geom_line and reversing the y-axis for rank?

ggplot(TmPostS, aes(x = yearID, y=OvSeaRank)) + geom_line() + geom_point() + 
scale_y_reverse() + ggtitle("ABC") + xlab("Year") + ylab("Rank of champion") + theme_light()

Answer 2

Thanks to Joe support, I could found what I wanted to show on this question. I was modifying stat = "identity" by stat = "bin" and defining a bindwidth = 1

ggplot(TmPostS, aes(x = yearID)) + geom_bar(stat="bin", binwidth = 1, color = "red", fill = "darkblue") + 
  ggtitle("World Series Champions based on their regular season W-L% overall rank") + xlab("Season") + ylab("") + facet_grid(OvSeaRank ~ .) +
  theme_bw() +
  theme(axis.text.y=element_blank(), 
        axis.ticks = element_blank())

Wished graph using facets

On this case now the data frame considers all the MLB champions since 1884.

Finally, using geom_line idea from Joe:

ggplot(TmPostS, aes(x = yearID, y=OvSeaRank)) + geom_line(colour = "darkblue") + geom_point(colour = "red") + 
  scale_y_reverse() + ggtitle("World Series Champions based on their regular season W-L% overall rank") + xlab("Year") + ylab("Rank of champion") + theme_light()

Alternative graph using geom_line