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LibraryDataType[datatype]

specifies the data type for a LibraryFunction argument or result to be datatype.

LibraryDataType[datatype,etype]

specifies an element type etype for data structures.

LibraryDataType[datatype,etype,d]

specifies an array depth d for array data types.

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LibraryDataType

LibraryDataType[datatype]

specifies the data type for a LibraryFunction argument or result to be datatype.

LibraryDataType[datatype,etype]

specifies an element type etype for data structures.

LibraryDataType[datatype,etype,d]

specifies an array depth d for array data types.

Details

  • Possible library data types include:
  • NullNull type (void)
    True | FalseBoolean values (mbool)
    StringUTF8 encoded strings (char *)
    Integermachine integers (mint)
    Realmachine reals (mreal)
    Complexmachine complex numbers (mcomplex)
    Listtensors of numerical values (MTensor)
    NumericArraynumeric arrays for LibraryLink (MNumericArray)
    SparseArraysparse arrays of numerical values for LibraryLink (MSparseArray)
    ByteArraybyte arrays for LibraryLink (MNumericArray)
    Image2D images for LibraryLink (MImage)
    Image3D3D images for LibraryLink (MImage)
    Image|Image3D2D or 3D images for LibraryLink (MImage)
  • For an image datatype, LibraryDataType[datatype,itype] specifies an ImageType of itype; LibraryDataType[datatype] allows any image type.

Examples

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Basic Examples  (1)

Load an example LibraryFunction that accepts a sparse array argument:

Wolfram Language code: props = LibraryFunctionLoad["demo_sparse", "sparse_properties", {"UTF8String", {LibraryDataType[SparseArray]}}, {_, _}];

Use the function to get a property from a sparse array:

Wolfram Language code: s = SparseArray[{{1, 0, 0}, {2 , 0, 3}}];
Wolfram Language code: props["ExplicitPositions", s]

Scope  (2)

Load an example LibraryFunction that returns Image of type "Real64":

Wolfram Language code: colorNegate = LibraryFunctionLoad["demo_image", "color_negate", {{LibraryDataType[Image], "Constant"}}, {LibraryDataType[Image, "Real64"]}];

Use the function to get the result:

Wolfram Language code: colorNegate[RandomImage[1, 10, "Real64"]]

This function preserves the type of input argument, so it fails to return the result for types different than "Real64":

Wolfram Language code: colorNegate[RandomImage[1, 10, "Real32"]]

Load an example LibraryFunction that returns a two-dimensional NumericArray of type "ComplexReal64":

Wolfram Language code: numericArrayComplexConjugate = LibraryFunctionLoad["demo_numericarray", "numericArrayComplexConjugate", {{LibraryDataType[NumericArray], "Constant"}}, {LibraryDataType[NumericArray, "ComplexReal64", 2]}];

Use the function to get the result:

Wolfram Language code: complex64 = NumericArray[RandomComplex[{-1 - I, 1 + I}, {2, 3}], "ComplexReal64"];
Wolfram Language code: numericArrayComplexConjugate[complex64]

This function preserves the type of input argument, so it fails to return the result for types different than "ComplexReal64":

Wolfram Language code: complex32 = NumericArray[RandomComplex[{-1 - I, 1 + I}, {2, 3}], "ComplexReal32"];
Wolfram Language code: numericArrayComplexConjugate[complex32]

This function preserves the rank of the input argument, so it fails to return the result for ranks different than 2:

Wolfram Language code: complex1D = NumericArray[RandomComplex[{-1 - I, 1 + I}, 3], "ComplexReal64"];
Wolfram Language code: numericArrayComplexConjugate[complex1D]
Wolfram Research (2014), LibraryDataType, Wolfram Language function, https://reference.wolfram.com/language/ref/LibraryDataType.html (updated 2019).

Text

Wolfram Research (2014), LibraryDataType, Wolfram Language function, https://reference.wolfram.com/language/ref/LibraryDataType.html (updated 2019).

CMS

Wolfram Language. 2014. "LibraryDataType." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2019. https://reference.wolfram.com/language/ref/LibraryDataType.html.

APA

Wolfram Language. (2014). LibraryDataType. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/LibraryDataType.html

BibTeX

@misc{reference.wolfram_2026_librarydatatype, author="Wolfram Research", title="{LibraryDataType}", year="2019", howpublished="\url{https://reference.wolfram.com/language/ref/LibraryDataType.html}", note=[Accessed: 12-June-2026]}

BibLaTeX

@online{reference.wolfram_2026_librarydatatype, organization={Wolfram Research}, title={LibraryDataType}, year={2019}, url={https://reference.wolfram.com/language/ref/LibraryDataType.html}, note=[Accessed: 12-June-2026]}