Concept: datatypes, conversions


#1

Hello!

I had a question about vectors some weeks ago, but it’s still not
everything clear to me.

I understand that converting a datastream to vector changes the
organisation of the data, or makes chunks of data that are processed as
a data block. For example you can feed the fft-blocks only vectors. What
is the organisation when it’s not vector?

There are some blocks converting to and from streams. What is a strem,
what is the difference to a vector, where do I need it?
How is serial and parallel connected to this?
Can give stream_to_streams any insight?

There is bytes_to_syms. I guess it’s for some kind of modulation scheme
like ASK. Doxygen docs say:
Convert stream of bytes to stream of +/- 1 symbols.
input: stream of bytes; output: stream of float
What does it do exactly, how can I convert it back, is there some link
to symbols in QPSK?

I saw data types c (complex), f (float), short (int, x bits), i
(integer, y bits), v (vector), p (parallel, alias to vector(?))
Is that all? What about char and uchar (float_to_char, float_to_uchar)?
vector is a type of organisation and can hold any of the other types,
excluded vector and parallel of course. Right?
What are x and y? Are the integer types signed or unsigned?

Is it possible to use any implicit conversion or is every conversion to
be done with [type1]to[type2] (like short_to_float)?

I hope some answers to this questions are able to enlighten my
understanding of GNURadio :slight_smile:

Patrick

Engineers motto: cheap, good, fast: choose any two
Patrick S.
Student of Telematik, Techn. University Graz, Austria


#2

Ping!

Anyone here who likes to comment my questions? I’d like to add it to the
wiki, in best quality.

Patrick

Engineers motto: cheap, good, fast: choose any two
Patrick S.
Student of Telematik, Techn. University Graz, Austria