I have the following hash: BodyTemp{$person_num}{$date} which has already been populated.

Suppose I want to find the number of values falling above a certain level for each person, and assign it to a hash of its own. I'd like to use Grep, but there's apparently a syntax problem: 

my @personlist=("1"..."1000")
my ($person,%high_temp_days);
foreach $person (@personlist) {
%high_temp_days{$person}=grep {$_>300} values %BodyTemp{$person};
#the above two lines are one line
}

[download]
Can someone help me fix this? Thanks a million!

In reply to How to extract a row or column of two-dimensional hash by PerlKitten

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