3.6 Limits of Numeric Types

It is sometimes useful to refer to the minimum or maximum possible value for a particular data type. Although the WFDB library has certain minimum requirements for its numeric types, the actual range of possible values depends on your C compiler, and the CPU and operating system where your program is running.

Note that the range of values for a particular signal is usually smaller than the possible range of values that can be stored in a WFDB_Sample variable. If you want to know the maximum and minimum values for a particular signal, refer to the adcres and adczero fields of the of the WFDB_Siginfo structure (see section Signal Information Structures).

The following macros (defined in ‘<wfdb/wfdb.h>’) can be used to determine the limits of integer types. In order to use these macros, your program must also include the statement #include <limits.h>.

WFDB_SAMPLE_MIN

Smallest value that can be stored as a WFDB_Sample.

WFDB_SAMPLE_MAX

Largest value that can be stored as a WFDB_Sample.

WFDB_DATE_MIN

Smallest value that can be stored as a WFDB_Date.

WFDB_DATE_MAX

Largest value that can be stored as a WFDB_Date.

WFDB_TIME_MIN

Smallest value that can be stored as a WFDB_Time.

WFDB_TIME_MAX

Largest value that can be stored as a WFDB_Time.

WFDB_GROUP_MAX

Largest value that can be stored as a WFDB_Group.

WFDB_SIGNAL_MAX

Largest value that can be stored as a WFDB_Signal.

WFDB_ANNOTATOR_MAX

Largest value that can be stored as a WFDB_Annotator.

The following macros can be used to determine the limits and precision of floating-point types. In order to use these macros, your program must also include the statement #include <float.h>.

WFDB_FREQUENCY_MAX

Largest finite value that can be represented as a WFDB_Frequency.

WFDB_FREQUENCY_DIG

Number of decimal digits of precision of a WFDB_Frequency.

WFDB_FREQUENCY_MAX_10_EXP

Largest finite power of 10 that can be represented as a WFDB_Frequency.

WFDB_FREQUENCY_EPSILON

The difference between 1.0 and the smallest value greater than 1.0 that can be represented as a WFDB_Frequency.

WFDB_GAIN_MAX

Largest finite value that can be represented as a WFDB_Gain.

WFDB_GAIN_DIG

Number of decimal digits of precision of a WFDB_Gain.

WFDB_GAIN_MAX_10_EXP

Largest finite power of 10 that can be represented as a WFDB_Gain.

WFDB_GAIN_EPSILON

The difference between 1.0 and the smallest value greater than 1.0 that can be represented as a WFDB_Gain.