Publication date: 07/15/2025

Structure of a Data Table

A data table has fixed rows and columns, while a spreadsheet is cell-based. In a spreadsheet, you can place data, headings, or formulas in any cell. In a data table, the structure organizes data for analysis, which JMP analysis and graphing platforms then use.

Column headings

Column names are column headings.

Columns

Columns contain data and are assigned one data type. Basic columns are either numeric or character. If a column contains both character and numeric data, the entire column’s data type is character, and the numbers are treated as character data. JMP also has specialized column types for capturing things such as images. JMP uses the column’s data type to determine analysis options and results. For more information about data types, see “Understand Modeling Types”.

Rows

Rows contain observations. If there is no observation for a row, that cell is left empty. In JMP, a dot signifies a missing numeric value, and a blank signifies a missing character value.

For more information about JMP data tables, see Understand Data Tables. For more information about JMP column properties, see “Column Properties in JMP” inUsing JMP.

JMP data tables cannot be arranged in a workbook like Excel. Each JMP data table is a separate file and appears in its own window. To combine multiple tables, see “Reshape Your Data” in Using JMP. For organizing JMP tables and output, see “Save and Run Scripts”.

Tip: To use data from two or more tables in a single analysis, use Virtual Join. For more information, see “Virtually Join Data Tables” in Using JMP.

Want more information? Have questions? Get answers in the JMP User Community (community.jmp.com).