EXAMPLE - Two-Column Statistical Functions

This example illustrates the following two-column statistical functions:

  • CORREL - Correlation co-efficient between two columns. See CORREL Function.
  • COVAR - Calculates the covariance between two columns. See COVAR Function.
  • COVARSAMP - Calculates the covariance between two columns using the sample population method. See COVARSAMP Function.

Source:

The following table contains height in inches and weight in pounds for a set of students.

StudentheightInweightLbs
170134
267135
367147
467160
572136
673146
771135
863145
967138
1066138
1171161
1270131
1374131
1467157
1573161
1670133
1763132
1864153
1964156
2072154

Transformation:

You can use the following transformations to calculate the correlation co-efficient, the covariance, and the sampling method covariance between the two data columns:

Transformation Name New formula
Parameter: Formula type Single row formula
Parameter: Formula round(correl(heightIn, weightLbs), 3)
Parameter: New column name 'corrHeightAndWeight'

Transformation Name New formula
Parameter: Formula type Single row formula
Parameter: Formula round(covar(heightIn, weightLbs), 3)
Parameter: New column name 'covarHeightAndWeight'

Transformation Name New formula
Parameter: Formula type Single row formula
Parameter: Formula round(covarsamp(heightIn, weightLbs), 3)
Parameter: New column name 'covarHeightAndWeight-Sample'

Results:

StudentheightInweightLbscovarHeightAndWeight-SamplecovarHeightAndWeightcorrHeightAndWeight
170134-2.876-2.732-0.074
267135-2.876-2.732-0.074
367147-2.876-2.732-0.074
467160-2.876-2.732-0.074
572136-2.876-2.732-0.074
673146-2.876-2.732-0.074
771135-2.876-2.732-0.074
863145-2.876-2.732-0.074
967138-2.876-2.732-0.074
1066138-2.876-2.732-0.074
1171161-2.876-2.732-0.074
1270131-2.876-2.732-0.074
1374131-2.876-2.732-0.074
1467157-2.876-2.732-0.074
1573161-2.876-2.732-0.074
1670133-2.876-2.732-0.074
1763132-2.876-2.732-0.074
1864153-2.876-2.732-0.074
1964156-2.876-2.732-0.074
2072154-2.876-2.732-0.074