First Things to Do After You Import the Data into R

After you successfully uploaded the data into R, I would recommend doing 5 checks before you start with analysis. In this example I’m using data-set iris which is a pre-loaded in R

Dimension

Check the dimensions (i.e number of rows and columns) of your dataset by using function dim().

dim(iris)
150   5
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Names

Identify the names of your variables in dataset.

names(iris) 
"Sepal.Length" "Sepal.Width"  "Petal.Length" "Petal.Width"  "Species"
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Structure

To get information about the structure of dataset (i.e if variable is numeric or factor).

str(iris)
'data.frame':	150 obs. of  5 variables:
 $ Sepal.Length: num  5.1 4.9 4.7 4.6 5 5.4 4.6 5 4.4 4.9 ...
 $ Sepal.Width : num  3.5 3 3.2 3.1 3.6 3.9 3.4 3.4 2.9 3.1 ...
 $ Species     : Factor w/ 3 levels "setosa","versicolor",..
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Header

Look the header of your dataset to get information about the variables and their values.

head(iris)
Sepal.Length Sepal.Width Petal.Length Petal.Width Species
1          5.1         3.5          1.4         0.2  setosa
2          4.9         3.0          1.4         0.2  setosa
3          4.7         3.2          1.3         0.2  setosa
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Missings

Look for missing data. In addition we will use the function sum and mean to summarize all the missings.

sum(is.na(iris$Sepal.Length))
mean(is.na(iris$Sepal.Length))
0
0
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Those are the first thing I usually do after I load a dataset in R.