The MATLAB®
javaArray function lets you create a Java® array that MATLAB handles as a single multidimensional array. You specify the number and size of
the array dimensions along with the class of objects you intend to store in it. Using the
one-dimensional Java array as its primary building block, MATLAB then builds a Java array that satisfies the dimensions requested in the
javaArray command.
To create a Java object array, use the MATLAB
javaArray function. For example, the following command creates a Java array of four lower level arrays, each containing five objects of the
java.lang.Double class.
dblArray = javaArray('java.lang.Double',4,5);The javaArray function does not initialize
values in the array. This code copies the first four rows of MATLAB array A,
containing randomly generated data, into dblArray.
A = rand(5); for m = 1:4 for n = 1:5 dblArray(m,n) = java.lang.Double(A(m,n)); end end dblArray
dblArray = java.lang.Double[][]: [0.2703] [0.3912] [0.3774] [0.6713] [0.8620] [0.1971] [0.7691] [0.2160] [0.4386] [0.9899] [0.8217] [0.3968] [0.7904] [0.8335] [0.5144] [0.4299] [0.8085] [0.9493] [0.7689] [0.8843]
You must convert each element of A to the java.lang.Double type.
For more information, see Pass Java Objects.
To pass an array of a primitive Java type to a Java method, you must pass in an array of the equivalent MATLAB type. For the type mapping details, see MATLAB Type to Java Type Mapping.
For example, create a java.awt.Polygon by
looking at the constructors in the following methods window.
methodsview('java.awt.Polygon')This constructor uses an array of Java int.
Polygon (int[],int[],int)
MATLAB converts a MATLAB double to
a Java scalar or array int. Create two MATLAB arrays,
identifying four points of a polygon.
x = [10 40 95 125 10]; y = [50 15 0 60 50]; polygon = java.awt.Polygon(x,y,length(x));
To call the Polygon object method contains,
look at its signature in the method window.
boolean contains (double,double)
MATLAB converts a MATLAB double to
a Java double. This statement checks if the
point (50,40) is within the polygon.
contains(polygon,50,40)
ans = logical 1