EXAMPLE - Two-Column Statistical Functions
This example illustrates statistical functions that can be applied across two columns of values.
Functions:
Item | Description |
|---|---|
CORREL Function | Computes the correlation coefficient between two columns. Source values can be of Integer or Decimal type. |
COVAR Function | Computes the covariance between two columns using the population method. Source values can be of Integer or Decimal type. |
COVARSAMP Function | Computes the covariance between two columns using the sample method. Source values can be of Integer or Decimal type. |
ROUND Function | Rounds input value to the nearest integer. Input can be an Integer, a Decimal, a column reference, or an expression. Optional second argument can be used to specify the number of digits to which to round. |
Source:
The following table contains height in inches and weight in pounds for a set of students.
Student | heightIn | weightLbs |
|---|---|---|
1 | 70 | 134 |
2 | 67 | 135 |
3 | 67 | 147 |
4 | 67 | 160 |
5 | 72 | 136 |
6 | 73 | 146 |
7 | 71 | 135 |
8 | 63 | 145 |
9 | 67 | 138 |
10 | 66 | 138 |
11 | 71 | 161 |
12 | 70 | 131 |
13 | 74 | 131 |
14 | 67 | 157 |
15 | 73 | 161 |
16 | 70 | 133 |
17 | 63 | 132 |
18 | 64 | 153 |
19 | 64 | 156 |
20 | 72 | 154 |
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 | |
|---|---|
Parameter: Formula type | Single row formula |
Parameter: Formula | round(correl(heightIn, weightLbs), 3) |
Parameter: New column name | 'corrHeightAndWeight' |
Transformation Name | |
|---|---|
Parameter: Formula type | Single row formula |
Parameter: Formula | round(covar(heightIn, weightLbs), 3) |
Parameter: New column name | 'covarHeightAndWeight' |
Transformation Name | |
|---|---|
Parameter: Formula type | Single row formula |
Parameter: Formula | round(covarsamp(heightIn, weightLbs), 3) |
Parameter: New column name | 'covarHeightAndWeight-Sample' |
Results:
Student | heightIn | weightLbs | covarHeightAndWeight-Sample | covarHeightAndWeight | corrHeightAndWeight |
|---|---|---|---|---|---|
1 | 70 | 134 | -2.876 | -2.732 | -0.074 |
2 | 67 | 135 | -2.876 | -2.732 | -0.074 |
3 | 67 | 147 | -2.876 | -2.732 | -0.074 |
4 | 67 | 160 | -2.876 | -2.732 | -0.074 |
5 | 72 | 136 | -2.876 | -2.732 | -0.074 |
6 | 73 | 146 | -2.876 | -2.732 | -0.074 |
7 | 71 | 135 | -2.876 | -2.732 | -0.074 |
8 | 63 | 145 | -2.876 | -2.732 | -0.074 |
9 | 67 | 138 | -2.876 | -2.732 | -0.074 |
10 | 66 | 138 | -2.876 | -2.732 | -0.074 |
11 | 71 | 161 | -2.876 | -2.732 | -0.074 |
12 | 70 | 131 | -2.876 | -2.732 | -0.074 |
13 | 74 | 131 | -2.876 | -2.732 | -0.074 |
14 | 67 | 157 | -2.876 | -2.732 | -0.074 |
15 | 73 | 161 | -2.876 | -2.732 | -0.074 |
16 | 70 | 133 | -2.876 | -2.732 | -0.074 |
17 | 63 | 132 | -2.876 | -2.732 | -0.074 |
18 | 64 | 153 | -2.876 | -2.732 | -0.074 |
19 | 64 | 156 | -2.876 | -2.732 | -0.074 |
20 | 72 | 154 | -2.876 | -2.732 | -0.074 |