Importing

Phoenix supports several types of data as input for:

Imported datasets such as worksheets and workbooks

User-created worksheets and workbooks

Worksheets that are the results of operational objects

A dataset must be mapped to an operational object before the data can be used.

The Data folder contains all imported or created datasets for a project. This means that all datasets used in a workflow are contained internally within Phoenix. Any changes made to a dataset once it has been imported into Phoenix will only affect the imported dataset. The external source file that contains the data will not be affected.

This section contains information on:

Importing files

Importing datasets

Special note about numeric data accuracy

Computer accuracy for numeric data is limited to about 14 significant digits. This can cause two unique numbers with more than 14 significant digits to be treated as the same number.

The situation for actual numerical data needs to be handled carefully. As an example, using the NCA Slopes Selector when the time data has more than 14 significant digits, and two points differ at the 14th digit (e.g., 240.333333333333 and 240.333333333334), one point appears selected for the time range, but it is not used in the Slopes Selector. Furthermore, the point representing a number, such as 240.333333333333, is selectable in the Slopes Selector and can show as the End Time for a user-specified range but will not be used in the slope calculation, causing Lambda_Z_Lower and Lambda_Z_Upper in the output to be off by 1e-14. One workaround is to click on Slopes and paste the full number. Another possibility is, prior to NCA, to round the time data so it has 14 significant digits or fewer (use a custom transformation in the Data Wizard with a formula such as round(time,10) or roundsig(time,14)).

If identifier data (e.g., subject IDs) being imported has many digits (e.g., 100010901), they are changed upon import to G8 format by default (e.g., 1.0001090E-08), even if they are imported as text. Using the G9 format preserves the identifier digits. See “Set Microsoft .NET format string” for more information on numeric formats.