How do I calculate correlations?

From Displayr
Jump to: navigation, search

There are two main ways to compute correlations in Displayr. The first is to use Insert > More > Correlation > Correlation Matrix to create a visual representation of correlations, and the second is to create a crosstab between two numeric variable sets.

Visualizing Correlations

To create an output which visualizes correlations as a heat map:

  1. Select Insert > More > Correlation > Correlation Matrix
  2. Select the variables that you want to investigate in the Variables box.
  3. Click Calculate.

Creating a Crosstab

You need to make a particular kind of cross-tab between two "numeric" sets of variables.
 
By "numeric" we mean that the Structure for the Variable Set is Numeric or Numeric - Multi (so that a table for the data shows Averages rather than Percentages).
 
The quickest steps would be:
 
1. Make a cross-tab between the two sets of data. You can use INSERT > Table to make a new table, or work with an existing table. In Inputs > DATA the Rows and Columns dropdowns should have the two sets of data selected.
2. If the data is already in the appropriate form then the table will show "Correlation" in the top left.
3. If the data is not in the right form then it can be changed by selecting one of the rows of the table and then selection DATA MANIPULATION > Structure > Averages (this treats the data as "numeric")
4. Do the same thing for the columns. 
 
The resulting table should now show a correlation statistic.