Normal forms: Difference between revisions
Wikispaces>genewardsmith **Imported revision 142172347 - Original comment: ** |
Wikispaces>genewardsmith **Imported revision 142172695 - Original comment: ** |
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<h2>IMPORTED REVISION FROM WIKISPACES</h2> | <h2>IMPORTED REVISION FROM WIKISPACES</h2> | ||
This is an imported revision from Wikispaces. The revision metadata is included below for reference:<br> | This is an imported revision from Wikispaces. The revision metadata is included below for reference:<br> | ||
: This revision was by author [[User:genewardsmith|genewardsmith]] and made on <tt>2010-05-15 | : This revision was by author [[User:genewardsmith|genewardsmith]] and made on <tt>2010-05-15 02:07:39 UTC</tt>.<br> | ||
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The revision contents are below, presented both in the original Wikispaces Wikitext format, and in HTML exactly as Wikispaces rendered it.<br> | The revision contents are below, presented both in the original Wikispaces Wikitext format, and in HTML exactly as Wikispaces rendered it.<br> | ||
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There are slightly different definitions of Hermite normal form in use, and if you are using a computer program to compute it, you should take care that the same normal monzo or val list is finally achieved. The definition used by the Wikipedia article on Hermite form, probably the most standard, works as follows. | There are slightly different definitions of Hermite normal form in use, and if you are using a computer program to compute it, you should take care that the same normal monzo or val list is finally achieved. The definition used by the Wikipedia article on Hermite form, probably the most standard, works as follows. | ||
An n by m integral matrix H is in Hermite normal form if when we define a function F such that F(i) = 0 if all of the entries in the ith column of H are 0, and otherwise F(i) is equal to the row number of the first nonzero entry in the ith column, | An n by m integral matrix H is in Hermite normal form if when we define a function F such that F(i) = 0 if all of the entries in the ith column of H are 0, and otherwise F(i) is equal to the row number of the first nonzero entry in the ith column, checking up from the bottom, ie from the nth row, we have | ||
(1) If i > j, H[i, j] = 0 (H is upper triangular.) | (1) If i > j, H[i, j] = 0 (H is upper triangular.) | ||
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There are slightly different definitions of Hermite normal form in use, and if you are using a computer program to compute it, you should take care that the same normal monzo or val list is finally achieved. The definition used by the Wikipedia article on Hermite form, probably the most standard, works as follows. <br /> | There are slightly different definitions of Hermite normal form in use, and if you are using a computer program to compute it, you should take care that the same normal monzo or val list is finally achieved. The definition used by the Wikipedia article on Hermite form, probably the most standard, works as follows. <br /> | ||
<br /> | <br /> | ||
An n by m integral matrix H is in Hermite normal form if when we define a function F such that F(i) = 0 if all of the entries in the ith column of H are 0, and otherwise F(i) is equal to the row number of the first nonzero entry in the ith column, | An n by m integral matrix H is in Hermite normal form if when we define a function F such that F(i) = 0 if all of the entries in the ith column of H are 0, and otherwise F(i) is equal to the row number of the first nonzero entry in the ith column, checking up from the bottom, ie from the nth row, we have<br /> | ||
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(1) If i &gt; j, H[i, j] = 0 (H is upper triangular.)<br /> | (1) If i &gt; j, H[i, j] = 0 (H is upper triangular.)<br /> | ||