FLSG620DA Users' Note

http://www.csar.cfs.ac.uk/test/software/maths/nag/mark20...

returned by X02AJF in Section 4

Thus a parameter described as real should be declared as DOUBLE PRECISION in your program. If a routine accumulates an inner product in additional precision, it is using software to simulate quadruple precision.

In routine documents that have been newly typeset since Mark 12 additional bold italicised terms are used in the published example programs and they must be interpreted as follows:

real

as an intrinsic function name -

DBLE

imag

 

-

DIMAG

cmplx

 

-

DCMPLX

conjg

constants, e.g. 1.0e-4

-

DCONJG

e in

- D, e.g. 1.0D-4

e in

formats, e.g. e12.4

- D, e.g. D12.4

All references to routines in Chapter F07 - Linear Equations (LAPACK) and Chapter F08 - Least-squares and Eigenvalue Problems (LAPACK) use the LAPACK name, not the NAG F07/F08 name. The LAPACK name is precision dependent, and hence the name appears in a bold italicised typeface.

The typeset examples use the single precision form of the LAPACK name. To convert this name to its double precision form, change the first character either from S to D or C to Z as appropriate.

For example:

sgetrf

refers to the LAPACK routine name -

DGETRF

cpotrs

-

ZPOTRS

3.4. Explicit Output from NAG Routines

Certain routines produce explicit error messages and advisory messages via output units which either have default values or can be reset by using X04AAF for error messages and X04ABF for advisory messages. (The default values are given in Section 4). The maximum record lengths of error messages and advisory messages (including carriage control characters) are 80 characters, except where otherwise specified. These routines are potentially not thread safe and in general output is not recommended in a multithreaded environment.

3.5. Interface Blocks

The NAG Fortran Library Interface Blocks define the type and arguments of each user callable NAG Fortran Library routine. These are not essential to calling the NAG Fortran Library from Fortran 90 programs. Their purpose is to allow the Fortran 90 compiler to check that NAG Fortran Library routines are called correctly. The interface blocks enable the compiler to check that:

(a)Subroutines are called as such

(b)Functions are declared with the right type

(c)The correct number of arguments are passed

(d)All arguments match in type and structure

These interface blocks have been generated automatically by analysing the source code for the NAG Fortran Library. As a consequence, and because these files have been thoroughly tested,

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Silicon Power Computer & comm FLSG620DA appendix Explicit Output from NAG Routines, Interface Blocks