SelectPrim

NAME

SelectSpec - select spectra
SelectPeak - select peaks
SelectPrim - select primitives
SYNOPSIS

SelectSpec expr
SelectPeak expr
SelectPrim expr
DESCRIPTION

Select spectra, peaks or primitives that satisfy a conditions specified by an expression. The expression must give a result of type boolean (truth value).

There are two special values not covered by the expression syntax below. If an empty string is given as expression, everything is selected. If the value "0" is given, nothing is selected (i. e. everything deselected).

The following is a formal sytax description of expressions in EBNF notation. Typical examples are shown in the next section.

  expr       = andExpr { "|" andExpr } .
  andExpr    = relExpr { "&" relExpr } .
  relExpr    = simpleExpr [ relOp setExpr ] .
  relOp      = "=" | "!=" | "<=" |
               "<" | ">=" | ">" .
  setExpr    = rangeExpr { "," rangeExpr } .
  rangeExpr  = simpeExpr [ ".." simpleExpr ] .
  simpleExpr = term { addOp term } .
  addOp      = "+" | "-" .
  term       = factor { mulOp factor } .
  mulOp      = "*" | "/" | "%" .
  factor     = [ "-" | "sqrt" | "log" | "!" ] primary .
  primary    = constant | designator | "(" expr ")" .
  constant   = string | int | float .
  designator = [ qual "." ] field [ "[" int "]" ] .
  qual       = "spec" | "peak" | "prim"
  field      = "num" | "number" | "name" | "attr" |
               "amp" | "symm" | "unif" | "qual" |
               "shift0" | "shift1" |
               "shift2" | "shift3" |
               "width0" | "width1" |
               "width2" | "width3" |
               propertyName .
For selecting items by their number or name, there is a shorter notation of the form:

  expr     = exprPart { exprPart } .
  exprPart = [ "#" set ] .
  set      = sel { "," sel } .
  sel      = string | range .
  range    = int ".." int | int "-" int .
Strings are not quoted in this notation.

The full and the short notation can be mixed, in this case a part written in the short notation behaves like a primary with a boolean value.

EXAMPLES

SelectSpec 'num > 2'
    # all spectra but the first two
SelectPeak 'qual > 0.3 & width0 > 4.0 & width1 > 1.0'
    # all peaks with minimal quality of 0.3 and
    # minimal line widths 4.0 and 1.0
SEE ALSO

DialSelect, DefPropMol,... , DialMol

DATE

960913


Reto Koradi, kor@mol.biol.ethz.ch