How to superimpose a line graph on a barplot in gg

Question

df2
          Year variable     value   pos
 1  2001-04-01 Purchase   4471.05  TRUE
 2  2002-04-01 Purchase   5084.00  TRUE
 3  2003-04-01 Purchase      0.00  TRUE
 4  2004-04-01 Purchase      0.00  TRUE
 5  2005-04-01 Purchase      0.00  TRUE
 6  2006-04-01 Purchase    740.00  TRUE
 7  2007-04-01 Purchase    720.00  TRUE
 8  2008-04-01 Purchase  13510.00  TRUE
 9  2009-04-01 Purchase 104480.34  TRUE
 10 2010-04-01 Purchase  85399.39  TRUE
 11 2011-04-01 Purchase  78799.05  TRUE
 12 2012-04-01 Purchase 142271.84  TRUE
 13 2013-04-01 Purchase 164240.00  TRUE
 14 2014-04-01 Purchase  54579.00  TRUE
 15 2015-04-01 Purchase     10.00  TRUE
 16 2016-04-01 Purchase  88124.00  TRUE
 17 2001-04-01     Sale  23795.10  TRUE
 18 2002-04-01     Sale  35418.45  TRUE
 19 2003-04-01     Sale  53401.52  TRUE
 20 2004-04-01     Sale  41598.01  TRUE
 21 2005-04-01     Sale   2899.24  TRUE
 22 2006-04-01     Sale   4652.71  TRUE
 23 2007-04-01     Sale   5845.26  TRUE
 24 2008-04-01     Sale   7587.17  TRUE
 25 2009-04-01     Sale   9932.03  TRUE
 26 2010-04-01     Sale   9931.45  TRUE
 27 2011-04-01     Sale  11574.75  TRUE
 28 2012-04-01     Sale   8186.81  TRUE
 29 2013-04-01     Sale  10737.00  TRUE
 30 2014-04-01     Sale   2577.00  TRUE
 31 2015-04-01     Sale  63428.00  TRUE
 32 2016-04-01     Sale  35800.00  TRUE
 33 2001-04-01      Net -19324.05 FALSE
 34 2002-04-01      Net -30334.59 FALSE
 35 2003-04-01      Net -53401.52 FALSE
 36 2004-04-01      Net -41598.01 FALSE
 37 2005-04-01      Net  -2899.24 FALSE
 38 2006-04-01      Net  -3912.71 FALSE
 39 2007-04-01      Net  -5125.38 FALSE
 40 2008-04-01      Net   5922.83  TRUE
 41 2009-04-01      Net  94548.32  TRUE
 42 2010-04-01      Net  75467.93  TRUE
 43 2011-04-01      Net  67224.30  TRUE
 44 2012-04-01      Net 134086.03  TRUE
 45 2013-04-01      Net 153503.00  TRUE
 46 2014-04-01      Net  16675.00  TRUE
 47 2015-04-01      Net -63418.00 FALSE
 48 2016-04-01      Net  52324.00  TRUE

Created a side by side barplot for rows 33 to 48:

library(ggplot2) #development version

p<-ggplot(df2[33:48,], aes(x=Year, y=value, fill=pos)) + 
   geom_bar(stat='identity', position='identity') + ggtitle("OMO (Rs'crores)\n") + theme(plot.title = element_text(lineheight=.8, face="bold",colour = "darkred",hjust =0.5,vjust = 2,size = 9)) + labs(x = "\nYear", y = "Rs crores\n",caption="Sources:Data is from RBI site")+scale_y_continuous(limits = c(-65000,200000),breaks =c(-60000,-30000,0,30000,60000,90000,120000,150000,180000,180000)) + scale_x_date(date_breaks = "2 year",date_labels = "%Y") 
p

I want to add (overlay) the rows 1 to 16 and 17 to 32 as 2 separate line plots on the above bargraph:

I tried this:

Adding the first line (variable=="purchase") p + geom_line(df2[1:16],aes(x=Year, y=value)) Error: ggplot2 doesn't know how to deal with data of class uneval

Where am I going wrong?

Answer 1

I think this is about what you want. I rearranged the dataframe, and adjusted the values a bit, and added a legend for the lines.

library(ggplot2)
df2 <- read.table(stringsAsFactors=F,text=
"Year variable     value   pos
1  2001-04-01 Purchase   4471.05  TRUE
2  2002-04-01 Purchase   5084.00  TRUE
3  2003-04-01 Purchase      0.00  TRUE
4  2004-04-01 Purchase      0.00  TRUE
5  2005-04-01 Purchase      0.00  TRUE
6  2006-04-01 Purchase    740.00  TRUE
7  2007-04-01 Purchase    720.00  TRUE
8  2008-04-01 Purchase  13510.00  TRUE
9  2009-04-01 Purchase 104480.34  TRUE
10 2010-04-01 Purchase  85399.39  TRUE
11 2011-04-01 Purchase  78799.05  TRUE
12 2012-04-01 Purchase 142271.84  TRUE
13 2013-04-01 Purchase 164240.00  TRUE
14 2014-04-01 Purchase  54579.00  TRUE
15 2015-04-01 Purchase     10.00  TRUE
16 2016-04-01 Purchase  88124.00  TRUE
17 2001-04-01     Sale  23795.10  TRUE
18 2002-04-01     Sale  35418.45  TRUE
19 2003-04-01     Sale  53401.52  TRUE
20 2004-04-01     Sale  41598.01  TRUE
21 2005-04-01     Sale   2899.24  TRUE
22 2006-04-01     Sale   4652.71  TRUE
23 2007-04-01     Sale   5845.26  TRUE
24 2008-04-01     Sale   7587.17  TRUE
25 2009-04-01     Sale   9932.03  TRUE
26 2010-04-01     Sale   9931.45  TRUE
27 2011-04-01     Sale  11574.75  TRUE
28 2012-04-01     Sale   8186.81  TRUE
29 2013-04-01     Sale  10737.00  TRUE
30 2014-04-01     Sale   2577.00  TRUE
31 2015-04-01     Sale  63428.00  TRUE
32 2016-04-01     Sale  35800.00  TRUE
33 2001-04-01      Net -19324.05 FALSE
34 2002-04-01      Net -30334.59 FALSE
35 2003-04-01      Net -53401.52 FALSE
36 2004-04-01      Net -41598.01 FALSE
37 2005-04-01      Net  -2899.24 FALSE
38 2006-04-01      Net  -3912.71 FALSE
39 2007-04-01      Net  -5125.38 FALSE
40 2008-04-01      Net   5922.83  TRUE
41 2009-04-01      Net  94548.32  TRUE
42 2010-04-01      Net  75467.93  TRUE
43 2011-04-01      Net  67224.30  TRUE
44 2012-04-01      Net 134086.03  TRUE
45 2013-04-01      Net 153503.00  TRUE
46 2014-04-01      Net  16675.00  TRUE
47 2015-04-01      Net -63418.00 FALSE
48 2016-04-01      Net  52324.00  TRUE")

# Rearrange the dataframe
df2$Year <- as.Date(df2$Year)
df3 <- df2[33:48,]
df3$sales <- df2[1:16,"value"]
df3$purchase <- df2[17:32,"value"]

# NOw plot it
p<-ggplot(df3, aes(x=Year, y=value)) + 

  # The bars  
  geom_bar(aes(fill=pos),stat='identity', position='identity') + 
  scale_fill_manual(name="Positive",values=c("TRUE"="gray30","FALSE"="darkred")) +

  # The Lines
  geom_line(aes(x=Year,y=purchase,color="purchase"),size=2) +
  geom_line(aes(x=Year,y=sales,color="sales"),size=2) +
  scale_y_continuous(limits = c(-65000,200000), breaks = 30000*(-2:6)) + 
  scale_x_date(date_breaks = "2 year",date_labels = "%Y") +
  scale_colour_manual(name="Value",values =c("purchase"="darkred","sales"="darkblue")) +

  ggtitle("OMO (Rs'crores)\n") + 
  theme(plot.title = element_text(lineheight=.8, face="bold",colour = "darkred",
                                  hjust =0.5,vjust = 2,size = 9)) + 
  labs(x = "\nYear", y = "Rs crores\n",caption="Sources:Data is from RBI site")

p

Yielding this:

Answer 2

reworked the above solution to get it right

Rearrange the dataframe

df2$Year <- as.Date(df2$Year)
df3 <- df2[33:48,]
df3$purchase <- df2[1:16,"value"]
df3$sales<- df2[17:32,"value"]
df3

NOw plot it

p<-ggplot(df3, aes(x=Year, y=value)) +   

The bars

geom_bar(aes(fill=pos),stat='identity', position='identity') + scale_fill_manual(name="Positive",values=c("TRUE"="#00BFC4","FALSE"="#F8766D")) + theme(panel.grid.minor = element_line(colour = "black", linetype = "dotted",size = 0.3)) + theme(panel.grid.major = element_line(colour = "black", linetype = "dotted",size = 0.3)) + theme(plot.background = element_rect(fill="#e0edbd" )) + theme(panel.background = element_rect(fill = "#fbfefe")) + scale_fill_discrete(name="",breaks=c("TRUE","FALSE"),labels=c("Net Purchases(+)","Net Sales(-)")) + 

The Lines

    geom_line(aes(x=Year,y=purchase,color="purchase"),size=1.35) +   geom_line(aes(x=Year,y=sales,color="sales"),size=1.35) + scale_y_continuous(limits = c(-65000,200000), breaks = 30000*(-2:6)) + 
  scale_x_date(date_breaks = "2 year",date_labels = "%Y") + scale_colour_manual(name="",values=c("#0072B2","#D55E00"),breaks=c("purchase","sales")) + ggtitle("Open Market Operation(OMO) since 2001 (Rs'crores)\n") + 
  theme(plot.title = element_text(lineheight=.8, face="bold",colour = "darkred",hjust =0.5,vjust = 2,size = 9)) + labs(x = "\nYear", y = "Rs'crores\n",caption="Sources:Data is from RBI site") + theme(plot.caption=element_text(size=8, hjust=1.4, margin=margin(t=10)))