A method and apparatus, including a computer program apparatus, which facilitate invoking methods of objects defined within an object-oriented environment from an array-based technical computing environment often used in conventional mathematical tools. When a method is invoked from the computing environment, the techniques automatically compare the array input parameters with data-types accepted by methods defined within the object-oriented environment. Based on this comparison, the invention selects a method that best accepts the input arrays. The invention, therefore, allows a user to easily invoke methods from external objects, such as Java objects, directly from the technical computing environment of the mathematical tool.