CODEWITHSUNDEEP
rbar-chart
Krellex
Krellex

Reputation: 753

Barchart result not matching data

I have a matrix containing some data which I have plotted to a barchart however when observing the barchart result the data appears incorrect. For example, a3 bar should be a value of 12 but it appears to go above 15 on the barchart. Quite new to R programming and would appreciate any insight into where I might be going wrong.

R

colors = c("blue","purple","brown")
assettypes <- c("a1","a2","a3","a4","a5", "a6")
groups <- c("c1","c2")

Values <- matrix(c(3,6,4,3,4,6,
                   12,9,12,12,11,9), nrow = 2, ncol = 6, byrow = TRUE)

barplot(Values, main = "C1 vs C2", names.arg = assettypes, xlab = "Assets", ylab = "Amount", col = colors)

legend("topleft", groups, cex = 1.3, fill = colors)

Barchart output enter image description here

Upvotes: 1

Views: 164

Answers (3)

Rfanatic
Rfanatic

Reputation: 2282

The code works fine and the values are stacked correctly. In order to avoid any possible misunderstanding, I changed the names of the groups to row 1 and row 2.

Sample code:

bb<-barplot(Values, 
            main = "Row 1 vs Row 2", 
            names.arg = assettypes, 
            xlab = "Assets", 
            ylab = "Amount", 
            col = colors, 
            ylim = c(0, 20))

legend("top", groups, cex = 1.3, fill = colors)

text(bb,Values [1,]+4,labels=Values [1,],font=2, cex=.8)
text(bb,colSums(Values)-13,labels=Values[2,],font=2, cex=0.8)

Plot: enter image description here

Sample data:

colors = c("blue","purple")
    assettypes <- c("a1","a2","a3","a4","a5", "a6")
    groups <- c("row 1","row 2")
    
    Values <-matrix(c(3,6,4,3,4,6,
                       12,9,12,12,11,9),
                       nrow = 2, ncol = 6, byrow = TRUE)



 Values

     [,1] [,2] [,3] [,4] [,5] [,6]
[1,]    3    6    4    3    4    6
[2,]   12    9   12   12   11    9

Upvotes: 1

Quinten
Quinten

Reputation: 41285

I think the stacked barplot plots the data right. Let's have a look at your Values:

colors = c("blue","purple","brown")
assettypes <- c("a1","a2","a3","a4","a5", "a6")
groups <- c("c1","c2")

Values <- matrix(c(3,6,4,3,4,6,
                   12,9,12,12,11,9), nrow = 2, ncol = 6, byrow = TRUE)

Output Values:

     [,1] [,2] [,3] [,4] [,5] [,6]
[1,]    3    6    4    3    4    6
[2,]   12    9   12   12   11    9

As you can see, a3 is 4+12 which means that it is 16. All other values are combined 15. So that is why the plot is right.

barplot(Values, main = "C1 vs C2", names.arg = assettypes, xlab = "Assets", ylab = "Amount", col = colors, beside=FALSE)

legend("topleft", groups, cex = 1.3, fill = colors)

Output barplot:

enter image description here

Upvotes: 1

Peter
Peter

Reputation: 12699

Perhaps a dodged barplot is required? Add beside = TRUE to the call to barplot (always worth checking the function help ?barplot).

Note:

  1. removed "brown" from colors as it seems as if there are only two groups in the dataset.
  2. moved the legend so that it does not overlap the bars.
colors = c("blue","purple")

barplot(Values, main = "C1 vs C2", names.arg = assettypes, xlab = "Assets", ylab = "Amount", col = colors, beside = TRUE)

legend("topright", groups, cex = 1, fill = colors)

Created on 2022-03-13 by the reprex package (v2.0.1)

Upvotes: 1

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