How do I use BooleanSelect?
- To: mathgroup at smc.vnet.net
- Subject: [mg6390] How do I use BooleanSelect?
- From: jason at pernet.com (jason welter)
- Date: Sun, 16 Mar 1997 19:24:58 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
BooleanSelect is a function in the DataManipulation.m add on package
in Statistics. It doesn't seem to work. Here's some background on it
as well as TakeWhile which does work:
??BooleanSelect
"BooleanSelect[list, sel] keeps elements of list for which the
corresponding element of sel is True."
Attributes[BooleanSelect] = {Protected, ReadProtected}
??TakeWhile
"TakeWhile[list, pred] takes elements from the beginning of list while
pred is True."
Attributes[TakeWhile] = {Protected, ReadProtected}
Here is some test data I have been using to explore these functions:
testa = {1,2,3,4,-2,y,6,7};
testb={{1,2},{-2,3},{23,56},{90,54},{-2,-200}};
The function TakeWhile works in the following way:
TakeWhile[testa,NumberQ]
Out[16]={1,2,3,4,-2}
Boolean Select does not:
BooleanSelect[testa,NumberQ]
Out[21]=BooleanSelect[{1,2,3,4,-2,y,6,7},NumberQ]
What I really need is a working function like BooleanSelect that will
let me sort through arrays, like "testb". I need to screen out all
groups in testb that either have -2 or -200 as an element. For
example:
BooleanSelect[testb,???]
{{1,2},{23,56},{90,54}};
There must be a way. What is it?