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ISELECT= item selection criterion = *, all items |
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Items to be selected may be specified by using the ISELECT= instruction to match characters within the item name. Items deleted by IDFILE= or similar are never selected by ISELECT=.
This can be done before analysis in the control file or with "Extra specifications". It can also be done after the analysis using the "Specification" pull-down menu.
Selection rules: Control characters match label or name. They start at the first column of the label or name. ? matches any character * matches any string of characters - must be last selection character. A matches A in the person label, and similarly all other characters except { } {..} braces characters which can match a single character: {ABC} matches A or B or C. {.. - ..} matches single characters in a range. {0-9} matches digits in the range 0 to 9. {.. --..} matches a single "-" {AB--} matches A or B or "-". {~ABX} omits person records which match A or B or X
Each ISELECT= performed using the "Specification" pull-down menu selects from all those analyzed. For incremental selections from the Specification menu, i.e., selecting from those already selected, specify +ISELECT=
Example 1: Select for analysis only items with M in the 5th column of item name.
ISELECT=????M* M in column means Math items
0001M 2x4 selected 0002R the cat omitted END NAMES
Example 2: Select for analysis all items with code "A 4" in columns 2-4 of their names. ISELECT="?A 4*" quotes because a blank is included. A is in col. 2 etc. ZA 4PQRS selected
Example 3: Select all Math (M in column 2) items which are Addition or Division (A or D in column 4): ISELECT="?M?{AD}*" 1M3A456 2+2 selected 1M5D689 23/7 selected 1H2A123 George omitted (History, American)
Example 3: Select codes A, 1,2,3,4,5,6 in column 3: ISELECT=??{A1-6}*
Example 4: Select "- " in columns 2 and 3: ISELECT="?- "
Example 5: Select "-" or "x" in column 2 with " " in column 3: ISELECT="?{--x} "
ISELECT=???M* in the Control file or at the Extra Specifications prompt. ISELECT=C* using the Specification pull-down menu, after the analysis +ISELECT=?{45}* using the Specification pull-down menu.
Example 7: 4 forms in one analysis with common items. Produce a score table for each form. In the item labels, columns 1-4 of item label are form indicator. Items can be in more than one form 1xxx for form1 items 12xx for form 1 and 2 items xx3x for form 3 xx34 for form 3 and 4 etc.
Then, use the Specification menu box: ISELECT = 1??? will select all items on form 1 Output Tables: Table 20 score table ISELECT = * select all items ISELECT = ?2?? will select all items on form 2 etc.
Example 8: Omit unwanted items, marked by "x" in the first character of the item label: ISELECT={~x}
Example 9: If the field to be selected is already identified, then this simplifies counting the column: @Dx = 16E17 ; $C44W2 16E17 means that the field is in columns 16 and 17 of the item label. Look at a data record to see what is actually there. ISELECT=???????????????23 ; selects "23" in columns 16 and 17 of the item label |
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