3. Data Types

Simple data types used by the WFDB library are defined in ‘<wfdb/wfdb.h>’. These include:

WFDB_Sample

a signed integer type (at least 16 bits) used to represent sample values, in units of adus.

WFDB_Time

a signed integer type (at least 32 bits) used to represent times and time intervals, in units of sample intervals. Only the magnitude is significant; the sign of a WFDB_Time variable indicates how it is to be printed by timstr or mstimstr.

WFDB_Date

a signed integer type (at least 32 bits) used to represent Julian dates, in units of days.

WFDB_Frequency

a floating point type used to represent sampling and counter frequencies, in units of Hz.

WFDB_Gain

a floating point type used to represent signal gains, in units of adus per physical unit.

WFDB_Group

an unsigned integer type used to represent signal group numbers.

WFDB_Signal

an unsigned integer type used to represent signal numbers.

WFDB_Annotator

an unsigned integer type used to represent annotator numbers.

Composite data types used by the WFDB library are also defined in ‘<wfdb/wfdb.h>’. These types, described in detail in the following sections, include:

WFDB_Siginfo

an object containing the name and global attributes of a given signal.

WFDB_Calinfo

an object containing calibration specifications for signals of a given type.

WFDB_Anninfo

an object containing the name and attributes of a given annotator.

WFDB_Annotation

an object describing one or more attributes of one or more signals at a given time.