111 
above currently goes via "matrix" and back instead of using the 'x' slot 
above currently goes via "matrix" and back instead of using the 'x' slot 
112 
directly; in particular, the triangular* "class property" is lost! 
directly; in particular, the triangular* "class property" is lost! 
113 


114 

Note that 'diag(M[,1]) < val' is deadly slow for large sparse M, 
115 

but that's because of the "outer" assignment in the equivalent 
116 

M[,1] < `diag<`(M[,1], val). 
117 


118 
 examples for solve( Cholesky(.), b, system = c("A", "LDLt"....)) 
 examples for solve( Cholesky(.), b, system = c("A", "LDLt"....)) 
119 
probably rather in man/CHMfactorclass.Rd than man/Cholesky.Rd 
probably rather in man/CHMfactorclass.Rd than man/Cholesky.Rd 
120 


180 
 <diagMatrix> o <ddenseMatrix> currently works via sparse, but 
 <diagMatrix> o <ddenseMatrix> currently works via sparse, but 
181 
should return <diagMatrix> in the same cases where 
should return <diagMatrix> in the same cases where 
182 
<diagMatrix> o <numeric> does. 
<diagMatrix> o <numeric> does. 
183 


184 

 look at solve.QP.compact() in \pkg{quadprog} and how to do that using 
185 

our sparse matrices. Maybe this needs to be reimplemented using CHOLMOD 
186 

routines. 
187 


188 

 "sparseVector" : indices, i.e. @i and @length should be changed 
189 

from class "integer" to "numeric" (i.e. double prec), 
190 

since we want to be able to coerce large sparse matrices to sparse 
191 

vectors, where length maybe considerably larger than 2^32. 