Re: [Discuss-gnuradio] forecast and set history function for haar decomposition

[Tom Rondeau]

On Wed, Oct 23, 2013 at 1:33 PM, Bharat Mukkala
<address@hidden> wrote:
> its true that setting the history to length of coefficients work, but when we
> go for more than 1 level of decomposition, the output from previous level
> will be used , so how can is use the output again ?

Seems to me like you'll need to keep that state inside the object.

> i have another doubt , if we set the size of each element in the input
> signature to be 4*sizeof(float) and size of each output element to be
> 4*sizeof(float)  in a gr::sync_block, then in the work function , how each
> element will be handled, (is it like 4 input items of size float), also
> please tell me how to use them.
> thank you

Look at some of the other blocks where a vector length is specified.
gr-blocks/lib/float_to_short_impl.cc might be a good one to look at.
The vlen used here means that each item is of size vlen times the size
of a float (on the input stream). If vlen=4, each item is composed of
4 floats. So if 'float *in = (float*)input_items[0]', then it has a
length of ninput_items[0]*4. You can index the array from 0 to
(ninput_items[0]*4 - 1).

Tom