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st: RE: Re: Extracting a submatrix based on multiple conditions
From
Nick Cox <[email protected]>
To
"'[email protected]'" <[email protected]>
Subject
st: RE: Re: Extracting a submatrix based on multiple conditions
Date
Fri, 1 Jul 2011 12:29:19 +0100
: select(y, (y[,2] :== 1 :& y[,3] :== 1))
1 2 3 4 5
+-----------------------------------------+
1 | 18049 1 1 91 2500 |
2 | 18079 1 1 124 2300 |
+-----------------------------------------+
Nick
[email protected]
Partho Sarkar
I am very new to Mata, so please excuse if this is too naive. I have
a very short question:
In Mata, is there a way, and if so what, to extract a submatrix of
rows where more than one condition is met, i.e., conditions on values
in 2 or more columns? E.g., in the following matrix
1 2 3 4 5
+-----------------------------------------+
1 | 18049 1 1 91 2500 |
2 | 18079 2 1 91 2500 |
3 | 18079 1 1 124 2300 |
+-----------------------------------------+
I want to extract the rows where the column 2 value==1 AND column 3
value==1 . As far as I can see so far, this is possible for a single
condition, e.g.,
y[.,3]:==1
would give me the row numbers where this condition is met. But this
does not work ( I tried with various parentheses):
y[.,3]:==1 & y[.1]:==1
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