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netcdf.inqUserType

Return information about user-defined type

Since R2022a

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Syntax

[typeName,byteSize,baseTypeID,numFields,classID] = netcdf.inqUserType(ncid,typeID)

Description

example

[typeName,byteSize,baseTypeID,numFields,classID] = netcdf.inqUserType(ncid,typeID) returns information about the user-defined type specified by the numeric type identifier in the file identified by ncid. The output arguments include the name of the user-defined type, the size in bytes of the type, the numeric identifier of the base type, the number of fields, and the class identifier of the user-defined type. Not all returned information is applicable for all user-defined types. The netcdf.inqUserType function corresponds to the nc_inq_user_type function in the NetCDF library C API.

Examples

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Open Live Script

Define an NC_VLEN type in a new NetCDF4 file and return information about it. An NC_VLEN type is a variable length array.

Create a new NetCDF4 file named myfile.nc. 

source = "myfile.nc";
cmode = "NETCDF4";
ncid = netcdf.create(source,cmode);

Define a new NC_VLEN type with the MY_VLEN type name and NC_DOUBLE base type.

typeName = "MY_VLEN";
baseType = "NC_DOUBLE";
typeID = netcdf.defVlen(ncid,typeName,baseType);

Return information about the NC_VLEN type using its numeric type identifier typeID.

[typeName,byteSize,baseTypeID,numFields, ...
    classID] = netcdf.inqUserType(ncid,typeID)
typeName = 
'MY_VLEN'

byteSize = 16

baseTypeID = 6

numFields = 0

classID = 13

The results include:

  • Name of the type

  • Size in bytes of the type

  • Numeric identifier of the base type

  • Number of fields (0 because it is not applicable for NC_VLEN types)

  • Identifier of the NC_VLEN class of user-defined types

Return the identifier of the NC_VLEN class. 13 is the identifier of the NC_VLEN class. 

netcdf.getConstant("NC_VLEN")
ans = 13

Close the NetCDF file.

netcdf.close(ncid)

Input Arguments

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File identifier of an open NetCDF file or OPeNDAP NetCDF data source, specified as an integer. You can retrieve this identifier by using the netcdf.open function.

Data Types: double

Data type identifier, specified as an integer. You can retrieve this identifier by using the netcdf.inqAtt or netcdf.inqVar functions.

Data Types: double

Output Arguments

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Name of the user-defined type, returned as a character vector.

Size in bytes of the user-defined type, returned as a double.

Type identifier for the base type of the user-defined type, returned as a double. For user-defined NC_VLEN types, the baseTypeID represents the type of the elements inside the user-defined variable-length array.

This returned information is not applicable for all user-defined types. The netcdf.inqUserType function returns baseTypeID as 0 when it is not applicable for the class of the specified user-defined type.

Number of fields of the user-defined type, returned as a double. This returned information is not applicable for all user-defined types. The netcdf.inqUserType function returns numFields as 0 when it is not applicable for the class of the specified user-defined type.

Class identifier of the user-defined type, returned as a double. For NC_VLEN types, the class identifier is 13. You can use the netcdf.getConstant function to return this identifier.

Version History

Introduced in R2022a

See Also

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