Arrange bars of a bar graph in R

Question

I’m filling the following data into the R to generate a bar chart:

structure(c(5483L, 28034L, 7995L, 5199L, 6785L, 7452L, 7692L), .Dim = 7L, .Dimnames = structure(list(c("dom", "qua", "qui", "sáb", "seg", "sex", "ter")), .Names = ""), class = "table")

I’m generating the following chart:

coresBasicas <- c(1:7)
DataDeAcessoPlot<- barplot(table(DataDeAcesso[,4]),
                           main = "Exibições de Páginas por Dias da Semana",
                           ylim = c(0,30000),
                           xlab="Dias da Semana",
                           col = coresBasicas,
                           ylab="Exibições de Páginas",
                           cex.axis = 0.6,
                           #cex.names = 0.6,
                           las=1
)
text(x=DataDeAcessoPlot, y=table(DataDeAcesso[,4]), label=table(DataDeAcesso[,4]), pos = 3, xpd=NA)

I would like to know how to organize the columns of the graphic in the following order: gift, mon, ter, qua, qui, fri, Sáb. Thanks from now on!

Answer 1

The first thing to do is to get a vector of abbreviated days of the week. For this I will use the functions Sys.Dat and weekdays. Then I order and apply the inverse function (again order).

# Hoje é segunda-feira, para começar no domingo tem que ser -1:5
y <- weekdays(Sys.Date() + -1:5, abbreviate = TRUE)
DDA <- DataDeAcesso[order(order(y))]

And just adapt the graph to use this vector DDA.

coresBasicas <- 1:7
DataDeAcessoPlot <- barplot(DDA,
                           main = "Exibições de Páginas por Dias da Semana",
                           ylim = c(0,30000),
                           xlab = "Dias da Semana",
                           col = coresBasicas,
                           ylab = "Exibições de Páginas",
                           cex.axis = 0.6,
                           #cex.names = 0.6,
                           las=1
)
text(x = DataDeAcessoPlot[, 1], y = DDA, label = DDA, pos = 3, xpd = NA)

Important issue.
In the above code I use the function Sys.Date to get a Monday. Now that changes every day and the rest stops working. You should not force the user to change the system date just to get it right with the date the question was asked and answered, the date this code was developed. So the best solution is to find a fixed day, which, by the way, is for example a Sunday to serve as a basis for the date vector from Sunday to Saturday, as asked in the question. For this just change a line of code above.

y <- weekdays(as.Date("2017-11-05") + 0:6, abbreviate = TRUE)

We get the vector

y
#[1] "dom" "seg" "ter" "qua" "qui" "sex" "sáb"

And the rest of the code is exactly the same and always works, today, tomorrow, next year, etc.