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Re: Fast copy of buffer data into a matrix
From: |
John W. Eaton |
Subject: |
Re: Fast copy of buffer data into a matrix |
Date: |
Fri, 9 Feb 2007 12:55:30 -0500 |
On 9-Feb-2007, John Swensen wrote:
| Is there a difference between:
| 1) static unit8NDArray m (dim_vector(settings.width, settings.height));
| and
| 2) static uint8NDArray m = octave_value(m1).uint8_array_value();
| ?
Yes. Is m1 a Matrix object? Assuming it is, then the first statement
creates a uint8NDArray object directly and the second takes m1 (double
values if it is a Matrix object), wraps it in an octave_value object,
then extracts a uint8NDArray object from it, requiring a type
conversion and data copying. So the second is a lot more work and
wastes space if all you really want is a uint8NDArray object.
jwe
- Fast copy of buffer data into a matrix, John Swensen, 2007/02/08
- Re: Fast copy of buffer data into a matrix, Nicolas Pettiaux, 2007/02/08
- Re: Fast copy of buffer data into a matrix, Muthiah Annamalai, 2007/02/08
- Re: Fast copy of buffer data into a matrix, John W. Eaton, 2007/02/09
- Re: Fast copy of buffer data into a matrix, John Swensen, 2007/02/09
- Re: Fast copy of buffer data into a matrix, John W. Eaton, 2007/02/09