How to Calculate the Difference between Two Columns using R

This article describes how to go from a crosstab...

..to an output displaying the difference between columns:

Requirements

A table with multiple rows and columns and a single statistic.

Method

1. Select your table.

2. Copy the name from Properties > GENERAL > Name

3. Select Calculation > Custom Code.

4. In the object inspector go to Properties > R CODE.

5. Add a line that subtracts the first column of the table from the second column using the table_name[row,column] reference format:

diff = table.preference.by.wave[,2] - table.preference.by.wave[,1]

6. [OPTIONAL] Alternatively, you can first define the table to make the formula tidier and even add the original table columns to the 'difference' column:

tab = table.preference.by.wave
diff = tab[,2] - tab[,1]
diff.table = cbind(tab,Difference=diff)

Next

How to Calculate the Difference Between Two Tables