Unsure about ggplot2 inputs

Question

I have a data frame that is fairly simple. It is a skills matrix for employees that contains user and 35-36 columns of IT skills with a ranking from 0-5. I summed each column and then sorted them DESC by skill value. Now I am looking to create a bar graph, but not sure what to put for the x value.

I have tried using colsums and colnames

Read CSV into R

skillsMatrix <- read.csv(file="skillsmatrix.csv", header=TRUE, sep=",")

colsums to find skills with highest values, sorted DESC

skills <- skillsMatrix[,names(sort(colSums(skillsMatrix[-1:-2]), decreasing = T))]
skills
library(ggplot2)
g <- ggplot(skills, aes(x= colSums(skills)), y=(colnames(skills))) + 
  geom_bar(stat = "identity", colour = "black")
g

expected results is to get a bar graph showing each skill with its value in descending order.

Actual result is this error:

Error: Aesthetics must be either length 1 or the same as the data (55): x

here is some output from str(skills) to give you an idea.

> str(skills)
'data.frame':   55 obs. of  35 variables:
 $ SQL                                         : int  4 3 2 3 3 2 3 3 3 4 ...
 $ IIS                                         : int  4 3 2 4 2 1 4 0 2 4 ...
 $ SQL.Server..SSIS..SSAS..SSRS.               : int  3 3 2 3 3 1 3 3 2 3 ...
 $ C.                                          : int  4 4 2 3 2 1 0 0 2 4 ...
 $ .Net..WCF..WPF.                             : int  4 2 1 2 2 2 0 0 2 4 ...
 $ VB..Net                                     : int  4 2 1 3 2 1 0 0 1 4 ...
 $ HTML.5                                      : int  3 4 3 2 1 1 0 2 1 2 ...
 $ Java.Script                                 : int  3 3 2 1 3 1 0 2 1 3 ...
 $ AppInsights                                 : int  1 1 1 3 2 0 3 0 0 3 ...
 $ Angular.JS                                  : int  2 3 2 2 2 0 0 2 2 2 ...

Please edit your question as shown [here](https://stackoverflow.com/questions/5963269/how-to-make-a-great-r-reproducible-example). — NelsonGon, Apr 04 '19 at 01:26

Ronak Shah · Answer 1 · 2019-04-04T01:41:23.830

1

Aesthetics should be of same length as data. You have different dimensions for skills dataset than the ones for aesthetic. We can create a new dataframe with sum of skills for each technology sorted in descending order and then use that for plotting.

library(ggplot2)

new_df <- stack(sort(colSums(skills), decreasing = TRUE))

ggplot(new_df) + 
      aes(ind, values) + 
      geom_bar(stat = "identity")

data

skills <- data.frame(SQL = c(4, 3, 2, 4, 2, 3),IIS = c(5, 1, 2, 4, 5, 5), 
                     Javascript = c(1, 2,3, 4, 5, 5))

edited Apr 04 '19 at 01:41

answered Apr 04 '19 at 01:36

Ronak Shah

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gotcha. Thank you. – Vegas588 Apr 04 '19 at 15:46

score 0 · Accepted Answer · edited Jun 20 '20 at 09:12

0

Here is an option with tidyverse. We summarise the columns to get the sum of each column, gather into 'long' format and then plot the bar plot with geom_bar from ggplot2

library(tidyverse)
library(ggplot2)
skillsMatrix %>% 
   summarise_all(sum) %>%
   gather %>% 
   ggplot(., aes(key, value)) + 
      geom_bar(stat = "identity")

data

skillsMatrix <- structure(list(SQL = c(4, 3, 2, 4, 2, 3), IIS = c(5, 1, 2, 4, 
 5, 5), Javascript = c(1, 2, 3, 4, 5, 5)), class = "data.frame", row.names = c(NA, 
  -6L))

edited Jun 20 '20 at 09:12

Community

1
1

answered Apr 04 '19 at 02:01

akrun

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37
540
662

Hi akrun, this is interesting too. skillsMatrix is slightly different to skills because in skillsMatrix there are two additional columns (ResourceName, Type). Both are currently listed as Factors. Would I change those columns to 'character' ? Error in Summary.factor(c(1L, 2L, 3L, 4L, 5L, 6L, 8L, 7L, 9L, 10L, 11L, : ‘sum’ not meaningful for factors – Vegas588 Apr 05 '19 at 10:57
@Vegas588 In that case, change the `summarise_all` to `summarise_if(is.numeric, sum)` and should work fine – akrun Apr 05 '19 at 12:27

Unsure about ggplot2 inputs

2 Answers2

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