Among the most basic classes are those used to implement vectors and matrices, defined in maspack.matrix. All vector classes implement the interface Vector and all matrix classes implement Matrix, which provide a number of standard methods for setting and accessing values and reading and writing from I/O streams.
As illustrated in the above example, vectors and matrices both provide a toString() method that allows their elements to be formatted using a C-printf style format string. This is useful for providing concise and uniformly formatted output, particularly for diagnostics. The output from the above example is
result= 4.000 12.000 12.000 24.000 20.000
Detailed specifications for the format string are provided in the documentation for NumberFormat.set(String). If either no format string, or the string "%g", is specified, toString() formats all numbers using the full-precision output provided by Double.toString(value).