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Use a2m to convert AHA-format annotation files into MIT format. Options for a2m include:
Use ad2m to convert AHA-format signal files into MIT format. Options for ad2m include:
Use ahaconvert to convert one or more records from an AHA DB CD-ROM into MIT format. Run ahaconvert without any command-line arguments for instructions, or see the examples below. Note: ahaconvert is a shell script; to use it successfully, you will need to have a shell (standard with all versions of Unix, and included in the free Cygwin package for MS-Windows) as well as ad2m and a2m, which perform the actual work of the conversion.
Use m2a to convert MIT-format annotation files into AHA tape format. Options for m2a include:
Use md2a to convert MIT-format signal files into AHA tape format. Options for md2a include:
MIT-format files can be excerpted and reformatted in more generally useful ways using snip(1) or xform(1) .
It may be necessary to set and export the shell variable WFDB (see setwfdb(1) ).
To convert the long-format records only, type:
ahaconvert /mnt/cdrom/?[01]??.cmp
To obtain the same files given a `short format' 9-track
distribution tape, copy the second and third files from the tape into files
1201.tap and 1201.ann in the current directory, then type:
ad2m -i 1201.tap -r 1201
a2m -i 1201.ann -r 1201 -a atr -t 1
The names for the files copied from the tape are arbitrary, but do not
use names of files to be generated by ad2m or a2m (see the previous example).
Note that the first and fourth files on the distribution tape contain
an `id' block, which can be read by readid (a program included in the convert
directory of the WFDB Software Package) to verify the record name. Distribution
tapes that contain more than one record contain additional sets of four
files, always in the same order within each set.
To
make a version of the three-hour AHA DB record 1001 in MIT format, given
the `long format' distribution tape, copy the second and third files from
the tape into files 1001.tap and 1001.ann in the current directory, then
type:
ad2m -i 1001.tap -r 1001 -t 3:0:0
a2m -i 1001.ann -r 1001 -a atr -t 2
The -t 3:0:0 option is necessary to prevent ad2m from truncating the signal
file after the first 35 minutes.
To make a version of AHA DB record 1201 in MIT format, given a `long
format' 9-track distribution tape containing the corresponding three-hour
record 1001, copy the second and third files from the tape into files 1001.tap
and 1001.ann in the current directory, then type:
ad2m -i 1001.tap -r 1201 -f 2:25:0
a2m -i 1001.ann -r 1201 -a atr -t 1
In this case, the -f option instructs ad2m to skip the first two hours and
25 minutes of the `long-format' AHA signal file, and to reformat the remainder
(equivalent to the 35-minute `short-format' record). The -t 1 option is used
with a2m even though its input file comes from a `long-format' tape, because
the annotation times must be shifted only by the amount necessary for a
`short-format' tape in this case.
To keep both versions (1001 and 1201) on-line,
make the `long format' version first (see above), then type:
a2m -i 1001.ann -r 1201 -a atr -t 1
to make a `short format' reference annotation file. Continue (under UNIX)
by:
cp 1001.hea 1201.hea
or (under MS-DOS) by:
copy 1001.hea 1201.hea
and edit 1201.hea, replacing `1001' in the first line (only!) with `1201', and
replacing `212' in the second and third lines by `212+6525000' (see the description
of the `byte offset' field in header(5)
). Although two header and reference
annotation files are needed, both versions can share the same signal file,
allowing a substantial savings in storage requirements. Note that WFDB
application programs that read the `short format' record 1201 signal file
may report signal checksum errors at the end of the record, unless you
also recalculate the signal checksums (easily done using snip(1)
to copy
the record; delete the copy once the checksums have been obtained).
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PhysioNetUpdated 12 May 2006