SciStat®
Variables
1. The basic variable: column heading
These variables refer directly to columns in the data table.
- The name of the variable is the heading you enter for the column in the data table.
- A variable name should not include any spaces, nor the following characters: - + / * = < > # & $ | ^ : , ; . ( ) ' " [ ] { }.
- The variable name should not start with a number and it must be different from reserved words such as TRUE, FALSE, ROW and COLUMN.
- The variable name should not be equal to the address of a spreadsheet cell such as A1, S1, AB35, IL6, etc.
2. Combination of variables
A mathematical formula combining two or more variables.
For example: WEIGHT/(HEIGHT*HEIGHT)
Any of the following operators can be used to combine variables (in order of precedence):
| ^ | Exponentiation |
| - | Negation |
| * / | Multiplication, Division |
| + - | Addition, subtraction |
As shown in the example, brackets can be used to change the operators precedence.
3. Transformation of a variable
When a variable needs transformation, you can use one of the many SciStat.com spreadsheet functions. For example, if a variable needs square root transformation you use the SQRT(variable) function as new variable.
How to create a derived variable
The example file ExampleFile2 contains data on body weight (in kg) and length (in m). You want to have a new variable Body Mass Index which is the weight divided by length squared.
Click Data in the SciStat.com menu. Next click Variables. The browser displays the variables in the data table.
Click the New variable hyperlink. A new input panel is displayed which you complete as follows:
Click Save and the new variable is added to the variables list:
