# How to summarize(add) a column according to same year and plot in R?

I have following type of data. But I would like to have graph with X-axis as Year and add all the sales added up in that year on Y- axis.

The Data frame name is salesdata. I have nearly 8000 rows of data. and the column headers are in the picture below.

Thanks!

## Step 1: Changing dates to years

First you can change your column of dates (Order_Date) to simply years by using this formula:

> salesdata$Order_Date = format(salesdata$Order_Date, "%Y")


This will give your Order Dates just the year the sales was done in.

## Step 2: Summarizing your sales data

After this you can create a vector with the summarizations of your sales data per year. This can be done using tapply:

> tapply(salesdata$Sales, salesdata$Order_Date, FUN=sum)


This will give you an overview of the total sales per year.

## Step 3: Plotting your graph

You can use barplot() to plot your bar chart using the values you got in your tapply function.

## One-liner

The function as a oneliner:

> barplot(tapply(salesdata$Sales, format(salesdata$Order_Date, "%Y"), FUN=sum))


### Step 1: Summarizing

You can use the dplyr package for that purpose, as:

library(dplyr)
x %>%
group_by(Order_Date) %>%
summarise(Sales = sum(Sales))


OR, this approach will work as well,

x %>%
group_by(Order_Date) %>%
summarise_each(funs(sum))


### Step 2: Plot

Once you're done with it, use ggplot to draw a plot of your interest, just use the respective function.

For more details visit these blogs-

Hope it helps!