(maxima.info)Functions and Variables for Miscellaneous Options

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33.3 Functions and Variables for Miscellaneous Options
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 -- System variable: askexp

     When 'asksign' is called, 'askexp' is the expression 'asksign' is
     testing.

     At one time, it was possible for a user to inspect 'askexp' by
     entering a Maxima break with control-A.

 -- Option variable: genindex
     Default value: 'i'

     'genindex' is the alphabetic prefix used to generate the next
     variable of summation when necessary.

 -- Option variable: gensumnum
     Default value: 0

     'gensumnum' is the numeric suffix used to generate the next
     variable of summation.  If it is set to 'false' then the index will
     consist only of 'genindex' with no numeric suffix.

 -- Function: gensym
          gensym ()
          gensym (<x>)

     'gensym()' creates and returns a fresh symbol.

     The name of the new symbol is the concatenation of a prefix, which
     defaults to "g", and a suffix, which is an integer that defaults to
     the value of an internal counter.

     If <x> is supplied, and is a string, then that string is used as a
     prefix instead of "g" for this call to gensym only.

     If <x> is supplied, and is a nonnegative integer, then that
     integer, instead of the value of the internal counter, is used as
     the suffix for this call to gensym only.

     If and only if no explicit suffix is supplied, the internal counter
     is incremented after it is used.

     Examples:

          (%i1) gensym();
          (%o1)                         g887
          (%i2) gensym("new");
          (%o2)                        new888
          (%i3) gensym(123);
          (%o3)                         g123

 -- Option variable: packagefile
     Default value: 'false'

     Package designers who use 'save' or 'translate' to create packages
     (files) for others to use may want to set 'packagefile: true' to
     prevent information from being added to Maxima's information-lists
     (e.g.  'values', 'functions') except where necessary when the file
     is loaded in.  In this way, the contents of the package will not
     get in the user's way when he adds his own data.  Note that this
     will not solve the problem of possible name conflicts.  Also note
     that the flag simply affects what is output to the package file.
     Setting the flag to 'true' is also useful for creating Maxima init
     files.

 -- Function: remvalue
          remvalue (<name_1>, ..., <name_n>)
          remvalue remvalue (all)

     Removes the values of user variables <name_1>, ..., <name_n> (which
     can be subscripted) from the system.

     'remvalue (all)' removes the values of all variables in 'values',
     the list of all variables given names by the user (as opposed to
     those which are automatically assigned by Maxima).

     See also 'values'.

 -- Function: rncombine (<expr>)

     Transforms <expr> by combining all terms of <expr> that have
     identical denominators or denominators that differ from each other
     by numerical factors only.  This is slightly different from the
     behavior of 'combine', which collects terms that have identical
     denominators.

     Setting 'pfeformat: true' and using 'combine' yields results
     similar to those that can be obtained with 'rncombine', but
     'rncombine' takes the additional step of cross-multiplying
     numerical denominator factors.  This results in neater forms, and
     the possibility of recognizing some cancellations.

     'load(rncomb)' loads this function.

 -- Function: setup_autoload (<filename>, <function_1>, ...,
          <function_n>)

     Specifies that if any of <function_1>, ..., <function_n> are
     referenced and not yet defined, <filename> is loaded via 'load'.
     <filename> usually contains definitions for the functions
     specified, although that is not enforced.

     'setup_autoload' does not work for 'memoizing functions'.

     'setup_autoload' quotes its arguments.

     Example:

          (%i1) legendre_p (1, %pi);
          (%o1)                  legendre_p(1, %pi)
          (%i2) setup_autoload ("specfun.mac", legendre_p, ultraspherical);
          (%o2)                         done
          (%i3) ultraspherical (2, 1/2, %pi);
          Warning - you are redefining the Macsyma function ultraspherical
          Warning - you are redefining the Macsyma function legendre_p
                                      2
                           3 (%pi - 1)
          (%o3)            ------------ + 3 (%pi - 1) + 1
                                2
          (%i4) legendre_p (1, %pi);
          (%o4)                          %pi
          (%i5) legendre_q (1, %pi);
                                        %pi + 1
                                %pi log(-------)
                                        1 - %pi
          (%o5)                 ---------------- - 1
                                       2

 -- Function: tcl_output
          tcl_output (<list>, <i0>, <skip>)
          tcl_output (<list>, <i0>)
          tcl_output ([<list_1>, ..., <list_n>], <i>)

     Prints elements of a list enclosed by curly braces '{ }', suitable
     as part of a program in the Tcl/Tk language.

     'tcl_output (<list>, <i0>, <skip>)' prints <list>, beginning with
     element <i0> and printing elements '<i0> + <skip>', '<i0> + 2
     <skip>', etc.

     'tcl_output (<list>, <i0>)' is equivalent to 'tcl_output (<list>,
     <i0>, 2)'.

     'tcl_output ([<list_1>, ..., <list_n>], <i>)' prints the <i>'th
     elements of <list_1>, ..., <list_n>.

     Examples:

          (%i1) tcl_output ([1, 2, 3, 4, 5, 6], 1, 3)$

           {1.000000000     4.000000000
           }
          (%i2) tcl_output ([1, 2, 3, 4, 5, 6], 2, 3)$

           {2.000000000     5.000000000
           }
          (%i3) tcl_output ([3/7, 5/9, 11/13, 13/17], 1)$

           {((RAT SIMP) 3 7) ((RAT SIMP) 11 13)
           }
          (%i4) tcl_output ([x1, y1, x2, y2, x3, y3], 2)$

           {$Y1 $Y2 $Y3
           }
          (%i5) tcl_output ([[1, 2, 3], [11, 22, 33]], 1)$

           {SIMP 1.000000000     11.00000000
           }