GraphPad Prism 8 User Guide

Dates

Dates

Previous topic Next topic No expanding text in this topic  

Dates

Previous topic Next topic JavaScript is required for expanding text JavaScript is required for the print function Emails questions or corrections.  

This page explains how to make graphs when you entered dates as X values. Another page explains how Prism 6 and earlier dealt with dates.

The Format Axis dialog offers two new choices when you entered dates instead of X values.

Date scale

At the top of the dialog, choose to use a Date scale.

DateAxis1

If you choose a Dates scale, you can choose many ways to display the dates. To avoid overlap, you'll probably want the dates to be displayed vertically or at an angle (not horizontal).

DateAxis3

When you choose a Dates axis scale, Prism is smart about how far to space the dates. Jan 3 is much closer to Jan 1 than is Feb 3...

Linear scale for X values entered as dates

If you choose a linear (numerical) scale for X values entered as dates, Prism tells you what the units will be.

DateAxis2

To change those units, go back to the data table, drop the Change menu and choose Format Data Table.

date time conversion

What values are used when you fit a curve or line to the data?

When you analyze XY data where X values are entered as dates, Prism converts the dates to numbers using a starting date and a date unit (days, weeks, etc.). To change this, go back to the data table, drop the change menu, and choose Format Data Table.