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## Re: Zero entries in one column of a matrix

**From**: |
Paul Kienzle |

**Subject**: |
Re: Zero entries in one column of a matrix |

**Date**: |
Fri, 2 Apr 2004 07:09:55 -0500 |

t1 = M(:,2) selects column 2
t2 = t1 ~= 0 turns the column into an index
t3 = M(t2,2) uses the boolean index t2 to select rows from column 2 of M
M(M(:,2) ~= 0,2) does all the above, including creating t1,t2,t3,
but not assigning names to them.
Paul Kienzle
address@hidden
On Thu, Apr 01, 2004 at 10:02:57AM -0800, Henry F. Mollet wrote:

Thanks for clear explanation.
Can I now also look at it as follows?
In M (: , 2) the ":" operator? says use all entries/rows in the second
column of M;
whereas in M (M(:,2) ~= 0 , 2), the implied ":" operator? looks at the
statement row by row and when it sees a boolean false (=0) says this is

`*not* an index and therefore the entry (which was an actual 0) has to
``be
`skipped?
Henry

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