Row & Column Summary Commands "RowMeans()" & "ColMeans()" in R language over dataframe and Matrix objects

 Special Row and Column Summary Commands

* Two summary commands used for row data are - rowMeans() and rowSums()

 

> rowMeans(mat01)

[1]  2.5  6.5 10.5 14.5

 

> rowSums(mat01)

[1] 10 26 42 58

 

* In the given example , each row in the dataframe has a specific row name

 

* If the names of the rows along with the values for the various rows would appear as a simple vector of values

 

> rowSums(mat01)

[1] 10 26 42 58

 

* The corresponding "colSums()" and "colMeans()" commands function in the same manner .

 

* In the following example ... one can see the "mean()" and "colMeans()" command with their comparison in the following manner :

> colMeans(df)

[1]  7  8  9 10

 

> mean(mf)

[1] 8.5

 

 

* One can see that one would essentially get the same display / result using the above two commands

 

* The commands use "na.rm" instruction which is used by default and is set to FALSE

 

* If one wants to ensure that the "NA" items are removed from the dataframe then one can add "na.rm = TRUE " as an instruction in the command