How Do I Use the CNiMatrix and CNiVector Classes?

[Chris_W1]

If I make a variable of type CNiMatrix or CNiVector I get the following errors:

error C2259: 'CNiMatrix' : cannot instantiate abstract class due to following members:

When I declare a variable of type CNiMatrixT or CNiVectorT, I get

error C2955: 'CNiMatrixT' : use of class template requires template argument list
error C2512: 'CNiMatrixT' : no appropriate default constructor available

How do I use these data types?

[Chris_W1]

Hello.

The "versions" of the vector and matrix data types that are intended for direct use are

CNiInt8Matrix, CNiInt8Vector-- Signed 8-bit Integer
CNiUInt8Matrix, CNiUInt8Vector-- Unsigned 8-bit Integer
CNiInt16Matrix, CNiInt16Vector-- Signed 16-bit Integer
CNiUInt16Matrix, CNiUInt16Vector-- Unsigned 16-bit Integer
CNiInt32Matrix, CNiInt32Vector-- Signed 32-bit Integer
CNiUInt32Matrix, CNiUInt32Vector-- Unsigned 32-bit Integer
CNiIntMatrix, CNiIntVector-- Signed Integer
CNiUIntMatrix, CNiUIntVector-- Unsigned Integer
CNiReal32Matrix, CNiReal32Vector-- 32-bit Floating Point
CNiReal64Matrix, CNiReal64Vector-- 64-bit Floating Point

It is probably wise for novice programmers to stick to using these classes only. The other matrix and vector classes do not add any functionality to the above classes, and can be more confusing to use.

Other related classes, like CNiMatrix and CNiVector, are abstract base classes and cannot be instantiated (you cannot define a variable as one of those types); their only purpose is to serve as base classes for other classes. Classes like CNiMatrixT and CNiVectorT are templatized classes. These classes require an argument before they can be instantiated. The template classes are used internally to construct the above twenty classes. National Instruments has defined these twenty classes to make the use of the vector and matrix classes simple by hiding the use of templates, which may be confusing to some programmers. You are certainly welcome to use the template classes directly if you want. In fact, you can see how National Instruments uses them in NiScalarMatrix.h and NiScalarVector.h, if you are interested. The definition of types like "Int8" can be found in NiCommon.h.

//==============================================================================
// Type Definitions
//==============================================================================
typedef CNiScalarMatrix CNiInt8Matrix;
typedef CNiScalarMatrix CNiUInt8Matrix;
typedef CNiScalarMatrix CNiInt16Matrix;
typedef CNiScalarMatrix CNiUInt16Matrix;
typedef CNiScalarMatrix CNiInt32Matrix;
typedef CNiScalarMatrix CNiUInt32Matrix;
typedef CNiScalarMatrix CNiIntMatrix;
typedef CNiScalarMatrix CNiUIntMatrix;
typedef CNiScalarMatrix CNiReal32Matrix;
typedef CNiScalarMatrix CNiReal64Matrix;


Regards,

Chris Wood
Applications Engineer
National Instruments