WFDB_getvec
Keywords: wfdb_tools

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WFDB_getvec

Usage: | `DATA = WFDB_getvec(NSIG);` |
| `DATA = WFDB_getvec(NSIG, NSAMP);` |
| `DATA = WFDB_getvec(NSIG, NSAMP, TSTART);` |
Input: | `NSIG`: number of signals |
| `NSAMP`: (optional) number of samples to read |
| `TSTART`: (optional) sample number of the first sample to read |
Output: | `DATA`: sample value(s) |

This function reads samples from open input signals. Typically, we prepare to use this function by

        S = WFDB_isigopen(record);
        NSIG = length(S);

to open the signals for a `record` of choice, and to determine `NSIG`, the number of signals available in the record.

To read `NSAMP` samples of each signal, beginning at sample number `TSTART`:

       DATA = WFDB_getvec(NSIG, NSAMP, TSTART);

The first sample of each signal has sample number 0 (not 1!).

To read the next `NSAMP` samples of each signal:

       DATA = WFDB_getvec(NSIG, NSAMP);

This form returns up to `NSAMP` samples, from sample number `T` to sample number `T+NSAMP`-1, where `T` is the input pointer (initially 0). The input pointer is incremented by the number of samples that have been read, so that a subsequent use of `WFDB_getvec` returns the next `NSAMP` samples, etc. Use `WFDB_isigsettime` (see section 3.4) to set the input pointer directly.

If the record is not too long, read it all at once by:

       DATA = WFDB_getvec(NSIG);

Note that recordings can be arbitrarily long and are often much larger than available memory; also note that there may be a very long delay if an entire record is read from a remote web server over a slow link.

Next: WFDB_getframe Up: Reading and Writing Signals Previous: Reading and Writing Signals Contents