Specify Column and Row of a String Search

Because I'm working with a very complex table with nasty repeated values in variable places, I'd like to do a string search between specific rows and columns.

For example:

table={{"header1", "header2", "header3", 
 "header4"}, {"falsepositive", "falsepositive", "name1", 
 "falsepositive"}, {"falsepositive", "falsepositive", "name2", 
 "falsepositive"}, {"falsepositive", "falsepositive", 
 "falsepositive", "falsepositive"}}

%//TableForm=
 header1          header1          header1          header1
 falsepositive    falsepositive    name1            falsepositive
 falsepositive    falsepositive    name2            falsepositive
 falsepositive    falsepositive    falsepositive    falsepositive

How do I look for a string, for example, in column three, rows one through two?

I'd like to use Which to assign values based on a string's location in the table.

E.g.,

Which[string matched in location one, value, matched in location two, value2]

Solution

As I understand it you want a test whether or not a given string is in a certain subsection of a matrix. You can pick these subsections using Part ([[...]]) and Span (;;), with which you can indicate ranges or subsamples of ranges. Testing whether or not this subsection contains your pattern can be done by MemberQ, like this:

 MemberQ[table[[1 ;; 2, 3]], "name2"]

 (* ==> False *)

 MemberQ[table[[1 ;; 2, 3]], "header3"]

(* ==> True *)

In this way, your Which statement could look like this:

myVar =
 Which[
  MemberQ[table[[1 ;; 2, 3]], "name2"], 5,
  MemberQ[table[[2 ;; 3, 4]], "falsepositive"], 6,
    ...
   True, 20
  ]