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st: RE: How to create a blank n x n matrix; how to refer to variables without using ID; how to extract colnames and rownames from the dataset.
From
Nick Cox <[email protected]>
To
"'[email protected]'" <[email protected]>
Subject
st: RE: How to create a blank n x n matrix; how to refer to variables without using ID; how to extract colnames and rownames from the dataset.
Date
Wed, 9 Mar 2011 13:07:45 +0000
Another take on this is that Mata offers a much more matrix-based view of your data. But as you're new to Stata you might want to hold off on getting into that.
Nick
[email protected]
-----Original Message-----
From: Nick Cox
Sent: 09 March 2011 13:04
To: '[email protected]'
Subject: RE: How to create a blank n x n matrix; how to refer to variables without using ID; how to extract colnames and rownames from the dataset.
Why Google when you can look at the help? That's like walking to the library to try to find a reference book when your friend the expert is next door and always available.
Less than a hour with -help matrix- will unearth functions like J(,,).
matrix mat1 = J(8,8,.)
is as blank as Stata will do for you; it contains missings.
The "first column of the dataset" is some non-Stata jargon for the first variable.
I don't understand question 3. Columns in Stata are called variables; rows are called observations; variables have names; observations have numbers. You don't so much extract these details as mention them when necessary.
Nick
[email protected]
Chen, Xianwen
I'm new to Stata and having been googling for following three
questions for more than an hour. I hope you can give me a hint.
The first question is a fast way to create a n x n matrix. For
example, to create a 8 x 8 matrix for later data manipulation. What I
now do is to create a matrix by
matrix define mat1=vect1,vect1,vect1,vect1,vect1,vect1,vect1,vect1
where vect1 is a 8x1 matrix
Is there a better way of doing it? For example, something like
matrix define mat1={1:8,1:8}
The second question is regarding variables. I want to search through
the variables by each entry of the data. I can specify the column IDs
but I want a more automated solution.
Is there a way of working with it, say
somefunction{1,}
will actually refer to the first column of the dataset?
The third question is to extract colnames and rownames from the
datasets. Is there a function I can use?
I'm sorry for bombing all question all together in an email if it
doesn't fit the netiquette here. I just don't want to send three
questions in three mails, which may be annoying.
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