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: http://xmm.vilspa.esa.es/sas/7.1.0/doc/selectlib/node3.html
Дата изменения: Mon Jul 9 00:08:50 2007 Дата индексирования: Sat Dec 22 11:14:09 2007 Кодировка: Поисковые слова: virgo cluster |
description | C/C++ form | Fortran form |
equal | == | .eq. |
not equal | != | .ne. |
less than | < | .lt. |
less than or equal | <= | .le. |
greater than | > | .gt. |
greater than or equal | >= | .ge. |
or | || | .or. |
and | && | .and. |
logical negation | ! | .not. |
inclusion test | in (see below) |
Operator precedences are as in C/C++ and parentheses may be used as necessary to group sub-expressions. Case is insignificant, i.e., .and., .AND., and .aNd. are all valid specifications for the logical and-operator. The C/C++ forms and Fortran forms can be mixed within a single expression.
In addition to the above operators, a limited set of boolean functions is available as well. These take a number of arguments and return either true or false. The following table lists the available boolean functions:
function name | meaning | comment |
ifthenelse(expr1, expr2, expr3) | if expr1 is true value of construct is value of expr2, otherwise value of expr3 | all three arguments must be boolean expressions |
near(val1,val2,tol) | true if
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point(...), line(...), ![]() |
point-in-figure test | see below |
gti(...), mask(...), region(...) | value-in-GTI/point in region tests | see below |
selected() or selected | selection status test | see below |