Re: Problem with method Plus in the Vector class

[Marco Turchi]

Hi
you are right about the sparse vector issue... but I'm constructing  
distV in the same way changing only + and - in the variable mean. In  
both the cases, I should have the same number of entries in the final  
vector.

Thanks a lot for your help
Marco

On 20 Jul 2011, at 17:42, Ted Dunning wrote:

You constructed the first vector with a dimension of 1.  It looks  
like you
constructed the second one with a larger dimension of 2.

When you offset a sparse vector, all of the zeros become non-zero  
and the
vector becomes dense.  This results in a bunch of cells being created.

On Wed, Jul 20, 2011 at 6:28 AM, marco turchi  
<marco.tur...@gmail.com>wrote:

Dear All,
I have a strange behaviour when I use the method Plus for Vector.

I have a RandomAccessSparseVector vector, if I add a positive  
number, I got
a new Vector where each element is the sum of the old value plus the
positive number. While if I add a negative number, the new vector  
has 1
more
entry:


RandomAccessSparseVector distV = new RandomAccessSparseVector(1);
distV.setQuick(0,1);
double mean = 1;
RandomAccessSparseVector app =
(RandomAccessSparseVector)(distV.plus(mean));

the output is
{0:2.0}

if I have
double mean = -1;
RandomAccessSparseVector app =
(RandomAccessSparseVector)(distV.plus(mean));

the output is
{1:1.0,0:-1.0}

For sure I'm doing something wrong. Do you have any ideas where the  
problem
is?

Thanks a lot in advance
Marco