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mdfInfo

Access or create MDF-file metadata

Since R2019b

Description

example

fileInfo = mdfInfo(mdfFileName) returns an MDFInfo object that contains information about the specified MDF-file, including name, location, version, size, initial timestamp of the data, and more. mdfFileName specifies an absolute, relative, or URL path to the MDF-file.

example

fileInfo = mdfInfo creates a default MDFInfo object that you can customize and use with mdfCreate to configure MDF-file metadata during file creation.

Examples

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Get the MDF-file information, and programmatically read its version.

fileInfo = mdfInfo("MDFFile.mf4");
fileInfo = 

  MDFInfo with properties:

   File Details
                  Name: "VehicleData.mf4"
                  Path: "E:\data\VehicleData.mf4"
                Author: ""
            Department: ""
               Project: ""
               Subject: ""
               Comment: "Example file with demo data."
               Version: "4.10"
      InitialTimestamp: 2022-01-20 01:22:34.000000000

   Creator Details
     ProgramIdentifier: "MATLAB"
     CreatorVendorName: "The MathWorks, Inc."
       CreatorToolName: "MATLAB"
    CreatorToolVersion: "9.12.0.1846952 (R2022a)"
       CreatorUserName: ""
        CreatorComment: ""

   File Contents
            Attachment: [1×8 table]
     ChannelGroupCount: 2

Read the Version property.

fileInfo.Version
ans =

    "4.10"

Create and modify an MDFInfo object for use in configuring a new MDF-file with customized metadata.

minfo = mdfInfo;
minfo.Comment = "25-Dec Shift B.";
%   ⋮
% Modify other properites as needed
%   ⋮
mdfCreate("MyMDFfile.mf4",FileInfo=minfo)

Input Arguments

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MDF-file name, specified as a string or character vector, including the necessary full or relative path. You can use a URL to specify a file on a remote server.

Depending on the location you are accessing, mdfFileName can take one of these forms.

Location

Form

Current folder or MATLAB® path

To access a file in the current folder or MATLAB path, specify the name of the file in filename, including the file extension.

Example: "myMdfFile.mf4"

Other folders

To access a file in a folder other than the current folder, specify the full or relative path name in filename.

Example: "C:\myFolder\myMdfFile.mf4"

Example: "\dataDir\myMdfFile.mf4"

Remote locations

To access a file in a remote location, filename must contain the full path of the file specified as a uniform resource locator (URL) of the form:

scheme://path_to_file/myMdfFile.mf4

Based on the remote location, scheme can be one of the values in this table.

Remote Locationscheme
Amazon S3™s3
Windows Azure® Blob Storagewasb, wasbs
HDFS™hdfs

For more information, see Work with Remote Data.

Example: "s3://bucketname/path_to_file/myMdfFile.mf4"

Data Types: char | string

Output Arguments

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MDF-file metadata information, returned as an MDFInfo object with the following properties:

MDFInfo Object Properties

Property NameData TypeAccess
File Details
NamestringRead-only
PathstringRead-only
AuthorstringRead/write
DepartmentstringRead/write
ProjectstringRead/write
SubjectstringRead/write
CommentstringRead/write
VersionstringRead/write
InitialTimestampdatetimeRead/write
Creator Details
ProgramIdentifierstringRead-only
CreatorVendorNamestringRead-only
CreatorToolNamestringRead-only
CreatorToolVersionstringRead-only
CreatorUserNamestringRead/write
CreatorCommentstringRead/write
File Contents
AttachmenttableRead-only
ChannelGroupCountuint64Read-only

Version History

Introduced in R2019b

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