| select | Select classes to a classified data frame |
| <frame> | name of the frame (any type) |
| -n <item-name> | item(s) to be selected |
This operation connects any possible item(s) to a frame and no type checking is done. Thus, the operation can also be used with data and classified data frames. It is also necessary to use this option, if fields of variable length are collected into a data frame.
Example: Membership functions of fuzzy sets are described as data fields of variable length. The following example demonstrates how some part of defined fuzzy sets can be selected to compute fuzzy values for the data values later. (For creating fuzzy sets, see Section 4.8.1 and related topics.)
... # Create a fuzzy structure and sets NDA> mkfz fz1... ... NDA> ls -fr fz1 fz1.sets fz1.sets.small fz1.sets.medium fz1.sets.large fz1.ranges ... NDA> select fz2.sets -n fz1.sets.small fz1.sets.large ... NDA> calcfz fz2 -f boston.dis -dout dis_fuzzy