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Matrix reshaping

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Matrix reshaping

I have a matrix, x, that is numeric and 49X47. The second row contains all missing values. I would like to reshape it to a square matrix that is 47x47 by eliminating the first and second rows. 

 

The SHAPE function isn't working: 

 

        x2=shape(x,3:49,47);

 

I'm getting execution errors telling me that the "argument should be a scalar."

 

How do I resolve this?

 

Thank you.


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‎10-10-2015 08:23 AM
SAS Super FREQ
Posts: 3,221

Re: Matrix reshaping

The documentation for the SHAPE function specifies that the second argument should be the number of columns in the result matrix. You are sending in a vector, which is why you are getting an error.

 

First use the subscript operator to  extract the nonmissing rows, then reshape:

x2 = shape( x[3:49, ], 47 );

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‎10-10-2015 08:23 AM
SAS Super FREQ
Posts: 3,221

Re: Matrix reshaping

The documentation for the SHAPE function specifies that the second argument should be the number of columns in the result matrix. You are sending in a vector, which is why you are getting an error.

 

First use the subscript operator to  extract the nonmissing rows, then reshape:

x2 = shape( x[3:49, ], 47 );
Frequent Contributor
Posts: 122

Re: Matrix reshaping

I think the subscript operator alone is suficient here.  The shape function does nothing as the reduced matrix already has 47 rows and 47 columns.

Contributor
Posts: 59

Re: Matrix reshaping

That specification of the Shape function worked. When I print the resulting matrix within IML, it is square. However, when I create output containing that matrix, the output resolves to a vector:

 

            Vec2 = the resulting square matrix

 

           create Outputx var {Vec2};
           append;
           close Outputx;

           run;*end Proc IML;

 

 

Outputx contains a single column with nxn rows.

 

Why does Outputx not contain the square matrix Vec2?

 

Thank you.

SAS Super FREQ
Posts: 3,221

Re: Matrix reshaping


 

Why does Outputx not contain the square matrix Vec2?

 


 

Because you are using the VAR clause in the CREATE statement. Use the FROM clause to write a matrix, as discussed in the article "Writing data from a matrix to a SAS data set."

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