Section author: Laiton Hedley

Row and V Functions

When creating formulas in jamovi, you can use either Row functions or Variable functions. These control whether your calculation uses values from within the same row or from an entire column.

Row Functions

Use Row functions when you want to calculate a value based only on other cells in the same row. For example, if you use MEAN(A, B, C), jamovi calculates the average of columns A, B, and C for each row individually.

Table 10 Example of the MEAN() function (Row-wise)

A	B	C	MEAN(A, B, C)
1	3	4	2.33
6	3	1	3.33
5	5	9	6.33

V Functions (Variable Functions)

Use V functions (Variable functions) when you want to perform a calculation using every value in a column. These are typically prefixed with the letter V. For example, VMEAN(A) calculates the mean of the entire column A and places that same result in every row.

Table 11 Example of the VMEAN() function (Variable-wise)

A	B	C	VMEAN(A)
1	3	4	4
6	3	1	4
5	5	9	4

You can combine Row and V functions in a single formula. A common use case is calculating a z-score manually:

(A - VMEAN(A)) / VSTDEV(A)

Note

For z-scores, you can also use the more concise Z(A) function.

Grouping with V Functions

Several V functions allow you to use a group_by parameter to calculate values within specific categories.

Suppose you have an outcome variable and a Dosage variable (e.g., 100 mg vs. 150 mg). To find the mean score for each dosage group separately, use:

VMEAN(outcome, group_by = Dosage)

Table 12 Example of VMEAN() with the group_by parameter

Dosage	outcome	VMEAN(outcome, group_by = Dosage)
150 mg	4	4.33
150 mg	4	4.33
150 mg	5	4.33
100 mg	3	3.00
100 mg	2	3.00
100 mg	4	3.00
50 mg	1	1.33
50 mg	2	1.33
50 mg	1	1.33