## Encyclopedia of sparse graph codes: Key to ascii files

### Files created by the programs 'gallager' and 'RA'

First, here are the column headings:
#blks es un det valid Eb/No(dB) x xass K N biters undet det block_ep
u l bit_ep u l blep_det undet bldetlw blep totlps lmax
undetu undetl
Now here are the meanings of these columns:
#blks number of block transmissions simulated
es number of block errors (total)
un number of block errors that were "undetected" errors
det number of block errors that were "detected" errors, also known as erasures
valid number of decodings that ended in a valid state corresponding to a codeword
Eb/No(dB) when computing this I use the "apparent rate" of the code K/N,
which may be smaller than the true rate, since there may be
redundancy in the parity check matrix.
x signal to noise ratio
xass snr assumed by the decoder
K
N
biters total number of bit errors in all those blocks
undet how many of the bit errors were in undetected blocks
det how many of the bit errors were in detected blocks
block_ep maximum likelihood estimate of block error prob
u ] error bars on this estimate
l ]
bit_ep estimate of bit error prob
u ] error bars on this estimate
l ]
blep_det estimate of detected block error probability
undet estimate of undetected block error probability
bldetlw (ignore this)
blep (and this)
totlps total number of iterations used to decode the valid blocks
lmax can't remember what this is
undetu ] error bars on undetected block error probability
undetl ]
A typical use of this file would be as follows:
to plot the total block error rate with error bars:
plot "a/273.82.3.353" u 6:14:15:16 t "" w error 1 2\
,"a/273.82.3.353" u 6:14 t "total" w linesp 1 2
to plot the detected block error rate and undetected error rate with error bars:
plot "a/273.82.3.353" u 6:20 t "detected" w linesp 2 6\
,"a/273.82.3.353" u 6:21 t "undetected" w linesp 3 3 \
,"a/273.82.3.353" u 6:21:26:27 t "" w error 3 3