modifyHeader

Modify header details of EDF or EDF+ file

Since R2021a

Syntax

edfw = modifyHeader(edfw,hdr)

Description

edfw = modifyHeader(edfw,hdr) modifies header fields in edfw using the header specified in the structure hdr.

Examples

Modify Header Record

Create a header record for an EDF file and specify the patient identification, recording information, and start time.

hdr = edfheader("EDF");
hdr.Patient = "001 M 2020";
hdr.Recording = "This is the original header record";
hdr.StartTime = "00.00.01"

hdr = struct with fields:
               Patient: "001 M 2020"
             Recording: "This is the original header record"
             StartDate: "12.02.24"
             StartTime: "00.00.01"
              Reserved: ""
        NumDataRecords: -1
    DataRecordDuration: 1 sec
            NumSignals: []
          SignalLabels: [0x0 string]
       TransducerTypes: [0x0 string]
    PhysicalDimensions: [0x0 string]
           PhysicalMin: []
           PhysicalMax: []
            DigitalMin: []
            DigitalMax: []
             Prefilter: [0x0 string]
        SignalReserved: [0x0 string]

Create a new EDF file that contains the header record and a random 10-sample signal. Specify in hdr the number of signals and the signal physical minimum and maximum values. Set the input sample type as physical.

sig = randn(10,1);
hdr.NumSignals = 1;
hdr.PhysicalMin = min(sig);
hdr.PhysicalMax = max(sig);
edfw = edfwrite("file.edf",hdr,sig,"InputSampleType","physical");

Create a new header structure with modified patient, recording, and start time information.

newhdr.Patient = "002 F 2020";
newhdr.Recording = "This is a test";
newhdr.StartTime = "11.11.10";

Modify the original header record in file with the new information in newhdr. Display the file properties.

edfw = modifyHeader(edfw,newhdr);
edfinfo("file.edf")

ans = 
  edfinfo with properties:

              Filename: "file.edf"
           FileModDate: "12-Feb-2024 21:34:55"
              FileSize: 532
               Version: "0"
               Patient: "002 F 2020"
             Recording: "This is a test"
             StartDate: "12.02.24"
             StartTime: "11.11.10"
           HeaderBytes: 512
              Reserved: ""
        NumDataRecords: -1
    DataRecordDuration: 1 sec
            NumSignals: 1
          SignalLabels: "Signal_1"
       TransducerTypes: ""
    PhysicalDimensions: ""
           PhysicalMin: -2.2588
           PhysicalMax: 3.5784
            DigitalMin: 0
            DigitalMax: 0
             Prefilter: ""
            NumSamples: 10
        SignalReserved: ""
           Annotations: [0x2 timetable]

Input Arguments

edfw — EDF or EDF+ file

edfwrite object

EDF or EDF+ file, specified as an edfwrite object.

hdr — Header

structure

Header, specified as a structure. hdr can contain one or more of these fields:

• Patient

• Recording

• StartDate

• StartTime

• SignalLabels

• TransducerTypes

• PhysicalDimensions

• PhysicalMin

• PhysicalMax

• DigitalMin

• DigitalMax

• Prefilter

• SignalReserved

See edfheader for more information about the possible fields in the header structure.

Data Types: struct

Output Arguments

edfw — EDF or EDF+ file

edfwrite object

EDF or EDF+ file, returned as an edfwrite object.

References

[1] Kemp, Bob, Alpo Värri, Agostinho C. Rosa, Kim D. Nielsen, and John Gade. “A Simple Format for Exchange of Digitized Polygraphic Recordings.” Electroencephalography and Clinical Neurophysiology 82, no. 5 (May 1992): 391–93. https://doi.org/10.1016/0013-4694(92)90009-7.

[2] Kemp, Bob, and Jesus Olivan. "European Data Format 'plus' (EDF+), an EDF Alike Standard Format for the Exchange of Physiological Data." Clinical Neurophysiology 114, no. 9 (2003): 1755–1761. https://doi.org/10.1016/S1388-2457(03)00123-8.

Version History

Introduced in R2021a