GraphPad Prism 8 User Guide

Troubleshooting: Negative numbers become positive; fractional numbers become integers?

Troubleshooting: Negative numbers become positive; fractional numbers become integers?

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Troubleshooting: Negative numbers become positive; fractional numbers become integers?

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Situations where negative values become positive when pasted or imported into a Prism table:

In a contingency table. the rows denote treatment or exposure and the columns denote alternative outcomes. Each value is the actual number of subjects, objects or events. Thus all values must be positive integers or zero. If the data you are importing has any negative values, the minus signs are simply ignored, so the value will become positive. If you want to include negative numbers, you are not really creating a contingency table. Drop the Change menu, choose Format Data Table, and choose a different kind of table. You probably want a Grouped table.

Excel can be configure to show negative values in red, without the negative sign. When you copy and paste this to Prism, the color is lost but the negative sign is not restored.

Some financial programs show negative numbers within parentheses. Prism does not understand this syntax, and the numbers will not be pasted as negative values.

In a survival table, the Y values are a code. One value (usually 1) indicates that the event (often death) occurred. The other value (usually 0) indicates that the data are censored after the specified X (time) value. Negative values are impossible.

Situations where fractional values can become integers when imported or pasted into a Prism table:

In a contingency table. the rows denote treatment or exposure and the columns denote alternative outcomes. Each value is the actual number of subjects, objects or events. Thus all values must be positive integers or zero. If the data you are importing or pasting has a decimal point, this will be ignored, so "1.23" will paste or import as "123".  If you want to include numbers of fractions, you are not really creating a contingency table. Drop the Change menu, choose Format Data Table, and choose a different kind of table. You probably want a Grouped table.

The Y columns of survival tables hold simple code values. Usually, 1 means death (or some other event happened) and 0 means the data were censored. You can change the code, but Prism can only accept integers into the Y columns of survival tables.

Number format can depend on where you (or whoever made the text file) lives. A comma sometimes denotes thousands, but sometimes is a decimal separator. If you have trouble, use Edit..Paste Special (instead of plain Paste). The first tab of Paste Special dialog (which is identical to the Import dialog) lets you define what commas mean.

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