void readnextblock(std::istream& sin, libbase::vector<S>& result,
int blocklength, const libbase::size_type<libbase::vector>& txsize)
{
if (blocklength > 0)
result.init(blocklength);
else
result.init(txsize);
result.serialize(sin);
}
void readsingleblock(std::istream& sin, libbase::vector<S>& result,
int blocklength)
{
std::list<S> items;
// Skip any preceding comments and whitespace
sin >> libbase::eatcomments;
// Repeat until end of stream
while (!sin.eof())
{
S x;
sin >> x >> libbase::eatcomments;
assertalways(sin.good() || sin.eof());
items.push_back(x);
}
std::cerr << "Read block of length = " << items.size() << std::endl;
// truncate if necessary
if (blocklength > 0 && blocklength < int(items.size()))
{
items.resize(blocklength);
std::cerr << "Truncated to length = " << items.size() << std::endl;
}
// copy to required object type
result.init(items.size());
typename std::list<S>::iterator i;
int j;
for (i = items.begin(), j = 0; i != items.end(); i++, j++)
result(j) = *i;
}
void experiment_binomial::estimate(libbase::vector<double>& estimate,
libbase::vector<double>& stderror) const
{
assert(count() == sum.size());
// initialize space for results
estimate.init(count());
stderror.init(count());
// compute results
assert(get_samplecount() > 0);
for (int i = 0; i < count(); i++)
{
// estimate is the proportion
estimate(i) = sum(i) / double(get_samplecount(i));
// standard error is sqrt(p(1-p)/n)
stderror(i) = sqrt((estimate(i) * (1 - estimate(i)))
/ double(get_samplecount(i)));
}
}
void experiment_normal::get_state(libbase::vector<double>& state) const
{
assert(count() == sum.size());
assert(count() == sumsq.size());
state.init(2 * count());
for (int i = 0; i < count(); i++)
{
state(i) = sum(i);
state(count() + i) = sumsq(i);
}
}
void lut_interleaver<real>::transform(const libbase::vector<int>& in,
libbase::vector<int>& out) const
{
const int tau = lut.size();
assertalways(in.size() == tau);
out.init(in.size());
for (int t = 0; t < tau; t++)
if (lut(t) == fsm::tail)
out(t) = fsm::tail;
else
out(t) = in(lut(t));
}
void experiment_normal::estimate(libbase::vector<double>& estimate,
libbase::vector<double>& stderror) const
{
assert(count() == sum.size());
assert(count() == sumsq.size());
// estimate is the mean value
assert(get_samplecount() > 0);
estimate = sum / double(get_samplecount());
// standard error is sigma/sqrt(n)
stderror.init(count());
if (get_samplecount() > 1)
for (int i = 0; i < count(); i++)
stderror(i) = sqrt((sumsq(i) / double(get_samplecount()) - estimate(i)
* estimate(i)) / double(get_samplecount() - 1));
else
stderror = std::numeric_limits<double>::max();
}
void commsys_stream_simulator<S, R>::sample(libbase::vector<double>& result)
{
do
{
// Advance by one frame
received_prev = received_this;
source_this = source_next;
received_this = received_next;
// Create next source frame
source_next = Base::createsource();
// Encode -> Map -> Modulate next frame
libbase::vector<S> transmitted = sys_tx->encode_path(source_next);
// Transmit next frame
received_next = sys_tx->transmit(transmitted);
#ifndef NDEBUG
// update counters
frames_encoded++;
#endif
} while (source_this.size() == 0);
// Shorthand for transmitted and received frame sizes
const int tau = this->sys->output_block_size();
const int rho = received_this.size();
// Get access to the commsys channel object in stream-oriented mode
const bsid& c = dynamic_cast<const bsid&> (*this->sys->getchan());
// Determine start-of-frame and end-of-frame probabilities
libbase::vector<double> sof_prior;
libbase::vector<double> eof_prior;
libbase::size_type<libbase::vector> offset;
if (eof_post.size() == 0) // this is the first frame
{
// Initialize as drift pdf after transmitting one frame
c.get_drift_pdf(tau, eof_prior, offset);
eof_prior /= eof_prior.max();
// Initialize as zero-drift is assured
sof_prior.init(eof_prior.size());
sof_prior = 0;
sof_prior(0 + offset) = 1;
// Initialize previous frame so we have something to copy
received_prev.init(offset);
received_prev = 0; // value not important as content is unused
}
else
{
// Use previous (centralized) end-of-frame posterior probability
sof_prior = eof_post;
// Initialize as drift pdf after transmitting one frame, given sof priors
c.get_drift_pdf(tau, sof_prior, eof_prior, offset);
eof_prior /= eof_prior.max();
}
// Assemble stream
libbase::vector<S> stream = concatenate(received_prev, received_this,
received_next);
// Extract received vector
const int start = received_prev.size() - offset + drift_error;
const int length = tau + eof_prior.size() - 1;
assertalways(start >= 0 && start <= stream.size());
assertalways(length >= 0 && length <= stream.size() - start);
libbase::vector<S> received = stream.extract(start, length);
// Get access to the commsys object in stream-oriented mode
commsys_stream<S>& s = dynamic_cast<commsys_stream<S>&> (*this->sys);
// Demodulate -> Inverse Map -> Translate
s.receive_path(received, sof_prior, eof_prior, offset);
// Store posterior end-of-frame drift probabilities
eof_post = s.get_eof_post();
#ifndef NDEBUG
// update counters
frames_decoded++;
#endif
// Determine estimated drift
int drift;
eof_post.max(drift);
drift -= offset;
// Centralize posterior probabilities
eof_post = 0;
const int sh_a = std::max(0, -drift);
const int sh_b = std::max(0, drift);
const int sh_n = eof_post.size() - abs(drift);
eof_post.segment(sh_a, sh_n) = s.get_eof_post().extract(sh_b, sh_n);
// Determine actual cumulative drift and error in drift estimation
cumulative_drift += rho - tau;
drift_error += drift - (rho - tau);
#ifndef NDEBUG
std::cerr << "DEBUG (commsys_stream_simulator): Actual acc. drift at sof = "
<< cumulative_drift - (rho - tau) << std::endl;
std::cerr << "DEBUG (commsys_stream_simulator): Actual frame drift = "
<< rho - tau << std::endl;
std::cerr << "DEBUG (commsys_stream_simulator): Actual acc. drift at eof = "
<< cumulative_drift << std::endl;
std::cerr << "DEBUG (commsys_stream_simulator): Acc. drift error at sof = "
<< drift_error - (drift - (rho - tau)) << std::endl;
std::cerr << "DEBUG (commsys_stream_simulator): Estimated frame drift = "
<< drift << std::endl;
std::cerr << "DEBUG (commsys_stream_simulator): Acc. drift error at eof = "
<< drift_error << std::endl;
std::cerr << "DEBUG (commsys_stream_simulator): Frames encoded = "
<< frames_encoded << std::endl;
std::cerr << "DEBUG (commsys_stream_simulator): Frames decoded = "
<< frames_decoded << std::endl;
#endif
// Initialise result vector
result.init(Base::count());
result = 0;
// For every iteration
libbase::vector<int> decoded;
for (int i = 0; i < this->sys->num_iter(); i++)
{
// Decode & update results
this->sys->decode(decoded);
R::updateresults(result, i, source_this, decoded);
}
// Keep record of what we last simulated
this->last_event = concatenate(source_this, decoded);
}