Datasets

About

OxonStat datasets are arranged in a grid with different variables being stored in columns and observations stored in rows. Each variable has a Name and a Data type, along with other properties (See Column properties). The name is used when selecting variables for analysis and plotting. It is also used in formulae and is displayed in the centre of the column heading. The available data types are specified below, a symbol for the Data type is displayed on the right of the column heading. Variables can also be derived from other variables. Derived variables show an symbol on the left of the column heading.

In addition one column can be set as the label column. The Label column is used in the statistics outputs and graphs to label the rows. The label column is indicated with a symbol on the left of the column heading. If a derived column is also set as the label column both symbols will appear in the left of the column header. You can set the label column using the Data menu or toolbar.

Settings for a variable can be changed in the Column properties dialog box. Column widths can be set by dragging the right hand end of a the column header to the desired size. You can use the Data menu items to change column type and alignments. You can also change column alignments using the toolbar. You can also open the Column properties dialog box by double clicking on a column header.

Data types

Each variable has a type, which can be one of the following. OxonStat can, within limits, convert one column type to another (See Convert column to for details). All variable types can hold a missing value, which is displayed as an empty cell. These are ignored in analyses and graphs.

Number () : Stores the single-precision floating-point format required to generate all analytical statistics and visual graphs.
Code list () : Maps numeric classifiers to categorical labels (e.g., assigning 1 = Male and 2 = Female) for stratified demographic analysis.
Text () : Holds alphanumeric strings like patient names or unencoded categorical descriptors (e.g., "Placebo", "Treatment"). OxonStat is able to convert one column type to another, allowing you to make a Code list from the text values.
Date () : Date variables, as the name suggests, store dates.
Time () : Time variables can store time using the 24 hour clock.

Tabs and windows

Even though OxonStat supports the Macintosh Tab system a Dataset only consists of a single table of columns and rows. Each tab is saved independently and does not form a workbook as it would in a spreadsheet application. The following image shows two different Datasets loaded into tabs in a window: