Data Options
Transformation and Merge Options. Each time the program executes a command, it reads the data file. Some data transformations (such as Compute and Recode) and file transformations (such as Add Variables and Add Cases) do not require a separate pass of the data, and execution of these commands can be delayed until the program reads the data to execute another command, such as a statistical or charting procedure.
- For large data files, where reading the data can take some time, you may want to select Calculate values before used to delay execution and save processing time. When this option is selected, the results of transformations you make using dialog boxes such as Compute Variable will not appear immediately in the Data Editor; new variables created by transformations will be displayed without any data values; and data values in the Data Editor cannot be changed while there are pending transformations. Any command that reads the data, such as a statistical or charting procedure, will execute the pending transformations and update the data displayed in the Data Editor. Alternatively, you can use Run Pending Transforms on the Transform menu.
- With the default setting of Calculate values immediately, when you paste command syntax from dialogs, an EXECUTE command is pasted after each transformation command. See the topic Multiple Execute Commands for more information.
Display Format for New Numeric Variables. Controls the default display width and number of decimal places for new numeric variables. There is no default display format for new string variables. If a value is too large for the specified display format, first decimal places are rounded and then values are converted to scientific notation. Display formats do not affect internal data values. For example, the value 123456.78 may be rounded to 123457 for display, but the original unrounded value is used in any calculations.
Set Century Range for 2-Digit Years. Defines the range of years for date-format variables entered and/or displayed with a two-digit year (for example, 10/28/86, 29-OCT-87). The automatic range setting is based on the current year, beginning 69 years prior to and ending 30 years after the current year (adding the current year makes a total range of 100 years). For a custom range, the ending year is automatically determined based on the value that you enter for the beginning year.
Random Number Generator. Two different random number generators are available:
- Version 12 Compatible. The random number generator used in version 12 and previous releases. If you need to reproduce randomized results generated in previous releases based on a specified seed value, use this random number generator.
- Mersenne Twister. A newer random number generator that is more reliable for simulation purposes. If reproducing randomized results from version 12 or earlier is not an issue, use this random number generator.
Assigning Measurement Level. For data read from external file formats, older IBM® SPSS® Statistics data files (prior to release 8.0) and new fields created in a session, measurement level for numeric fields is determined by a set of rules, including the number of unique values. You can specify the minimum number of data values for a numeric variable used to classify the variable as continuous (scale) or nominal. Variables with fewer than the specified number of unique values are classified as nominal.
There are numerous other conditions that are evaluated prior to applying the minimum number of data values rule when determining to apply the continuous (scale) or nominal measurement level. Conditions are evaluated in the order listed in the table below. The measurement level for the first condition that matches the data is applied.
| Condition | Measurement Level |
|---|---|
| Format is dollar or custom-currency | Continuous |
| Format is date or time (excluding Month and Wkday) | Continuous |
| All values of a variable are missing | Nominal |
| Variable contains at least one non-integer value | Continuous |
| Variable contains at least one negative value | Continuous |
| Variable contains no valid values less than 10,000 | Continuous |
| Variable has N or more valid, unique values* | Continuous |
| Variable has no valid values less than 10 | Continuous |
| Variable has less than N valid, unique values* | Nominal |
* N is the user-specified cut-off value. The default is 24.
Rounding and Truncation of Numeric Values. For the RND and TRUNC functions, this setting controls the default threshold for rounding up values that are very close to a rounding boundary. The setting is specified as a number of bits and is set to 6 at install time, which should be sufficient for most applications. Setting the number of bits to 0 produces the same results as in release 10. Setting the number of bits to 10 produces the same results as in releases 11 and 12.
- For the RND function, this setting specifies the number of least-significant bits by which the value to be rounded may fall short of the threshold for rounding up but still be rounded up. For example, when rounding a value between 1.0 and 2.0 to the nearest integer this setting specifies how much the value can fall short of 1.5 (the threshold for rounding up to 2.0) and still be rounded up to 2.0.
- For the TRUNC function, this setting specifies the number of least-significant bits by which the value to be truncated may fall short of the nearest rounding boundary and be rounded up before truncating. For example, when truncating a value between 1.0 and 2.0 to the nearest integer this setting specifies how much the value can fall short of 2.0 and be rounded up to 2.0.
Customize Variable View. Controls the default display and order of attributes in Variable View. See the topic Changing the default variable view for more information.
Change Dictionary. Controls the language version of the dictionary used for checking the spelling of items in Variable View. See the topic Spell checking for more information.