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Miscellaneous Options

Introduction to Miscellaneous Options

In this section various options are discussed which have a global effect on the operation of Maxima. Also various lists such as the list of all user defined functions, are discussed.

Share

The Maxima "share" directory contains programs and other files of interest to Maxima users, but not part of the core implementation of Maxima. These programs are typically loaded via load or setup_autoload.

:lisp *maxima-sharedir* displays the location of the share directory within the user's file system.

printfile ("share.usg") prints an out-of-date list of share packages. Users may find it more informative to browse the share directory using a file system browser.

Definitions for Miscellaneous Options

System variable: aliases
Default value: []

aliases is the list of atoms which have a user defined alias (set up by the alias, ordergreat, orderless functions or by declaring the atom a noun with declare).

Declaration: alphabetic
declare (char, alphabetic) adds char to Maxima's alphabet, which initially contains the letters A through Z, a through z, % and _. char is specified as a string of length 1, e.g., "~".

(%i1) declare ("~", alphabetic);
(%o1)                         done
(%i2) foo~bar;  
(%o2)                        foo~bar
(%i3) atom (foo~bar);
(%o3)                         true

Function: apropos (string)
Searches for Maxima names which have string appearing anywhere within them. Thus, apropos (exp) returns a list of all the flags and functions which have exp as part of their names, such as expand, exp, and exponentialize. Thus if you can only remember part of the name of something you can use this command to find the rest of the name. Similarily, you could say apropos (tr_) to find a list of many of the switches relating to the translator, most of which begin with tr_.

Function: args (expr)
Returns the list of arguments of expr, which may be any kind of expression other than an atom. Only the arguments of the top-level operator are extracted; subexpressions of expr appear as elements or subexpressions of elements of the list of arguments.

The order of the items in the list may depend on the global flag inflag.

args (expr) is equivalent to substpart ("[", expr, 0). See also substpart.

See also op.

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.

Constant: inf
Real positive infinity.

Constant: infinity
Complex infinity, an infinite magnitude of arbitrary phase angle. See also inf and minf.

System variable: infolists
Default value: []

infolists is a list of the names of all of the information lists in Maxima. These are:

labels - all bound %i, %o, and %t labels.

values - all bound atoms which are user variables, not Maxima options or switches, created by : or :: or functional binding.

functions - all user-defined functions, created by :=.

arrays - declared and undeclared arrays, created by :, ::, or :=.

macros - any macros defined by the user.

myoptions - all options ever reset by the user (whether or not they are later reset to their default values).

rules - user-defined pattern matching and simplification rules, created by tellsimp, tellsimpafter, defmatch, or defrule.

aliases - atoms which have a user-defined alias, created by the alias, ordergreat, orderless functions or by declaring the atom as a noun with declare.

dependencies - atoms which have functional dependencies, created by the depends or gradef functions.

gradefs - functions which have user-defined derivatives, created by the gradef function.

props - atoms which have any property other than those mentioned above, such as atvalues, matchdeclares, etc., as well as properties specified in the declare function.

let_rule_packages - a list of all the user-defined let rule packages plus the special package default_let_rule_package. (default_let_rule_package is the name of the rule package used when one is not explicitly set by the user.)

Function: integerp (expr)
Returns true if expr is a literal numeric integer, otherwise false.

integerp returns false if its argument is a symbol, even if the argument is declared integer.

Examples:

(%i1) integerp (0);
(%o1)                         true
(%i2) integerp (1);
(%o2)                         true
(%i3) integerp (-17);
(%o3)                         true
(%i4) integerp (0.0);
(%o4)                         false
(%i5) integerp (1.0);
(%o5)                         false
(%i6) integerp (%pi);
(%o6)                         false
(%i7) integerp (n);
(%o7)                         false
(%i8) declare (n, integer);
(%o8)                         done
(%i9) integerp (n);
(%o9)                         false

Option variable: m1pbranch
Default value: false

m1pbranch is the principal branch for -1 to a power. Quantities such as (-1)^(1/3) (that is, an "odd" rational exponent) and (-1)^(1/4) (that is, an "even" rational exponent) are handled as follows:

              domain:real
                            
(-1)^(1/3):      -1         
(-1)^(1/4):   (-1)^(1/4)   

             domain:complex              
m1pbranch:false          m1pbranch:true
(-1)^(1/3)               1/2+%i*sqrt(3)/2
(-1)^(1/4)              sqrt(2)/2+%i*sqrt(2)/2

Function: numberp (expr)
Returns true if expr is a literal integer, rational number, floating point number, or bigfloat, otherwise false.

numberp returns false if its argument is a symbol, even if the argument is a symbolic number such as %pi or %i, or declared to be even, odd, integer, rational, irrational, real, imaginary, or complex.

Examples:

(%i1) numberp (42);
(%o1)                         true
(%i2) numberp (-13/19);
(%o2)                         true
(%i3) numberp (3.14159);
(%o3)                         true
(%i4) numberp (-1729b-4);
(%o4)                         true
(%i5) map (numberp, [%e, %pi, %i, %phi, inf, minf]);
(%o5)      [false, false, false, false, false, false]
(%i6) declare (a, even, b, odd, c, integer, d, rational,
     e, irrational, f, real, g, imaginary, h, complex);
(%o6)                         done
(%i7) map (numberp, [a, b, c, d, e, f, g, h]);
(%o7) [false, false, false, false, false, false, false, false]

Function: properties (a)
Returns a list of the names of all the properties associated with the atom a.

Special symbol: props
props are atoms which have any property other than those explicitly mentioned in infolists, such as atvalues, matchdeclares, etc., as well as properties specified in the declare function.

Function: propvars (prop)
Returns a list of those atoms on the props list which have the property indicated by prop. Thus propvars (atvalue) returns a list of atoms which have atvalues.

Function: put (atom, value, indicator)
Assigns value to the property (specified by indicator) of atom. indicator may be the name of any property, not just a system-defined property.

put evaluates its arguments. put returns value.

Examples:

(%i1) put (foo, (a+b)^5, expr);
                                   5
(%o1)                       (b + a)
(%i2) put (foo, "Hello", str);
(%o2)                         Hello
(%i3) properties (foo);
(%o3)            [[user properties, str, expr]]
(%i4) get (foo, expr);
                                   5
(%o4)                       (b + a)
(%i5) get (foo, str);
(%o5)                         Hello

Function: qput (atom, value, indicator)
Assigns value to the property (specified by indicator) of atom. This is the same as put, except that the arguments are quoted.

Example:

(%i1) foo: aa$ 
(%i2) bar: bb$
(%i3) baz: cc$
(%i4) put (foo, bar, baz);
(%o4)                          bb
(%i5) properties (aa);
(%o5)                [[user properties, cc]]
(%i6) get (aa, cc);
(%o6)                          bb
(%i7) qput (foo, bar, baz);
(%o7)                          bar
(%i8) properties (foo);
(%o8)            [value, [user properties, baz]]
(%i9) get ('foo, 'baz);
(%o9)                          bar

Function: rem (atom, indicator)
Removes the property indicated by indicator from atom.

Function: remove (a_1, p_1, ..., a_n, p_n)
Function: remove ([a_1, ..., a_m], [p_1, ..., p_n], ...)
Function: remove ("a", operator)
Function: remove (a, transfun)
Function: remove (all, p)
Removes properties associated with atoms.

remove (a_1, p_1, ..., a_n, p_n) removes property p_k from atom a_k.

remove ([a_1, ..., a_m], [p_1, ..., p_n], ...) removes properties p_1, ..., p_n from atoms a_1, ..., a_m. There may be more than one pair of lists.

remove (all, p) removes the property p from all atoms which have it.

The removed properties may be system-defined properties such as function or mode_declare, or user-defined properties.

A property may be transfun to remove the translated Lisp version of a function. After executing this, the Maxima version of the function is executed rather than the translated version.

remove ("a", operator) or, equivalently, remove ("a", op) removes from a the operator properties declared by prefix, infix, nary, postfix, matchfix, or nofix. Note that the name of the operator must be written as a quoted string.

remove always returns done whether or not an atom has a specified property. This behavior is unlike the more specific remove functions remvalue, remarray, remfunction, and remrule.

Function: remvalue (name_1, ..., name_n)
Function: 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 possiblity of recognizing some cancellations.

Function: scalarp (expr)
Returns true if expr is a number, constant, or variable declared scalar with declare, or composed entirely of numbers, constants, and such variables, but not containing matrices or lists.

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 array 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


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