MATLAB BUILDER JA 2 Guide de l'utilisateur télécharger pdf (Page 60)

3 Programming

return ret;

}

finally

{

MWArray.disposeArray(y);

if (cls != null)

cls.dispose();

}

The getrandvectors m ethod returns a two-dimensional double array w ith

a triangular structure. The length of the

ith row equals i. Such a rrays are

commonly referred to a s jagged arrays. Jagged arrays are easily supported in

Java becaus e a Java matrix is just an array of arrays.

Handling Return Values

Thepreviousexamplesusedthefactthatyouknewthetypeand

dimensionality of the output argument. In the case that this information is

unknown, or can vary (as is possible in M-programming), the code that calls

the method m ight need to query the type and dimensionality of the output

arguments.

Therearetwobasicwaystodothis.Youcandooneofthefollowing:

• UsereflectionsupportintheJavalanguagetoqueryanyobjectforitstype.

• Use several methods provided by the

MWArray class to query information

about the underlying MATLAB array.

Code Fragment: Using Java Reflection

This code sample calls the myprimes method, and then determines the type

using reflection. The example assumes that the output is returned as a

numeric matrix but the exact numeric type is unknown.

public void getprimes(int n) throws MWException

{

myclass cls = null;

Object[] y = null;

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MATLAB BUILDER JA 2 Guide de l'utilisateur Page 60