I am trying to implement a tridiagonal_matrix (<a href="http://en.wikipedia.org/wiki/Tridiagonal_matrix">http://en.wikipedia.org/wiki/Tridiagonal_matrix</a>)<br>It is just a special case for a banded_matrix, where there are only one diagonal above and under the main diagonal.
<br><br>That is, a tridiagonal_matrix&lt;T&gt;(m, n) is functionally equivalent to a banded_matrix&lt;T&gt;(m,n,1,1) (I probably want to make it square but that is another subject)<br><br>I&#39;d like to take advantage of very useful compile time info:
<br>1) all elements outside the diagonals are zero<br>2) there are only three (3 compile time fixed!) diagonals<br><br>e.g<br><br>matrix&lt;double&gt; x;<br>tridiagonal_matrix&lt;double&gt; y;<br>matrix&lt;double&gt; z1 = prod(x,y);
<br>matrix&lt;double&gt; z2 = x + y;<br><br>Both prod and operator+ should know that all values of y outside the three diagonals are zero, to save many operations respect a (dense) matrix<br><br>Is this possible with ublas? How is this done?
<br>TIA<br>&nbsp;