On entry: describes the Fortran format code that is used in conjunction with
USEFRM for printing the elements of the matrix
A. The format code may be any allowed on the system, whether it is standard Fortran or not. It may or may not be enclosed in brackets.
In addition, there are the following special codes which force X04DDF to choose its own format code:
- ${\mathbf{FORM}}=\text{''}$
- X04DDF will choose a format code such that numbers will be printed with an F8.4, an F11.4 or a 1PE13.4 format. The F8.4 code is chosen if the sizes of the real and imaginary parts of all the matrix elements to be printed lie between $0.001$ and $1.0$. The F11.4 code is chosen if the sizes of all the numbers to be printed lie between $0.001$ and $9999.9999$. Otherwise the 1PE13.4 code is chosen.
- ${\mathbf{FORM}}=\text{'*'}$
- X04DDF will choose a format code such that numbers will be printed to as many significant digits as are necessary to distinguish between neighbouring machine numbers. Thus any two numbers that are stored with different internal representations should look different on output. Whether they do in fact look different will depend on the run-time library of the Fortran compiler in use.
By preceding the desired format code by the string ‘MATLAB’, X04DDF will print the matrix such that it can be input into MATLAB, and
TITLE will be used as the name of the matrix.
More complicated values of
FORM, to print a
complex
number in a desired form, may be used. See the description of parameter
USEFRM for more details.
Examples of valid values for
FORM are
$\text{'(F11.4)'}$,
$\text{'1P,2E13.5'}$,
$\text{'MATLABF11.4'}$,
$\text{'MATLAB*'}$.
Constraint:
the character length of the format specifier in
FORM must be
$\text{}\le 80$.