Naming Conventions
The names of the routines are mnemonic and unique. Most routines are available in both a single precision and a double precision version, with names of the two versions sharing a common root. The root name is also the generic interface name. The name of the double precision specific version begins with a “D_.” The single precision specific version begins with an “S_”. For example, the following pairs are precision specific names of routines in the two different precisions: S_UVSTA/D_UVSTA (the root is “UVSTA ,” for “Basic Univariate Statistics”) and S_TWFRQ/D_TWFRQ (the root is “TWFRQ,” for “Two-Way Frequency Table”). Of course the generic name can be used as an entry point for all precisions supported.
Except when expressly stated otherwise, the names of the variables in the argument lists follow the FORTRAN default type for integer and floating point. In other words, a variable whose name begins with one of the letters “I” through “N” is of type INTEGER, and otherwise is of type REAL or DOUBLE PRECISION, depending on the precision of the routine.
An assumed size array with more than one dimension that is used as a FORTRAN argument can have an assumed-size declarator for the last dimension only. In the MATH/LIBRARY routines, the information about the first dimension is passed by a variable with the prefix “LD” and with the array name as the root. For example, the argument LDA contains the leading dimension of array A. In most cases, information about the dimensions of arrays is obtained from the array through the use of Fortran 90’s size function. Therefore, arguments carrying this type of information are usually defined as optional arguments.
Where appropriate, the same variable name is used consistently throughout a chapter in the STAT LIBRARY. For example, in the routines for random number generation, NR denotes the number of random numbers to be generated, and R or IR denotes the array that stores the numbers.
When writing programs accessing the STAT LIBRARY, the user should choose FORTRAN names that do not conflict with names of IMSL subroutines, functions, or named common blocks. The careful user can avoid any conflicts with IMSL names if, in choosing names, the following rules are observed:
Do not choose a name that appears in the Alphabetical Summary of Routines, at the end of the User’s Manual, nor one of these names preceded by a D, S_, D_, C_, or Z_.Do not choose a name consisting of more than three characters with a numeral in the second or third position.For further details, see the section on Reserved Names in the Reference Material section of this manual.
