Boolean operations can be used to piece together multiple evaluations. R has three boolean operators: The AND operator, & ; The NOT operator, ! ; And the OR ... ... <看更多>

You're searching for: Boolean or wildcard operator, Special character, Example. a word where you only know the first few letters, *, We've search on Pe* in ... ... <看更多>

Using quotes and Boolean operators will alter which items are considered most relevant. Both SpringerLink and Springer for R&D support the AND, ... ... <看更多>