1. A computer-implemented method for a computing environment employing a matrix-based mathematical programming language, the method comprising: generating a heterogeneous dataset in the computing environment, where: the heterogeneous dataset having at least a first variable, a second variable, a plurality of subjects, and information relating to at least the first variable, the second variable, and the plurality of subjects, the first variable and the second variable embody a plurality of variables for the plurality of subjects, the information describes the plurality of variables and the plurality of subjects, each element of a respective variable has a same data type, the variables comprise at least two data types, and the elements of the at least two data types being measured or collected data concerning the plurality of subjects; accessing contents of the heterogeneous dataset with a single command in the computing environment, where: the single command is based on at least one of: a command to access contents of the heterogeneous dataset for one of the variables and for one of the subjects, a command to access contents of the heterogeneous dataset for all subjects associated with one of the variables, or a command to access contents of the heterogeneous dataset for a portion of the plurality of the variables and for a portion of the plurality of the subjects; and providing in the computing environment a portion of the heterogeneous dataset based on the single command.