Next: Functions and Variables for Display, Previous: Introduction to Command Line, Up: Command Line [Contents][Index]
__ is the input expression currently being evaluated. That is, while an
input expression expr is being evaluated, __ is expr.
__ is assigned the input expression before the input is simplified or
evaluated. However, the value of __ is simplified (but not evaluated)
when it is displayed.
__ is recognized by batch and load. In a file processed
by batch, __ has the same meaning as at the interactive prompt.
In a file processed by load, __ is bound to the input expression
most recently entered at the interactive prompt or in a batch file; __
is not bound to the input expressions in the file being processed. In
particular, when load (filename) is called from the interactive
prompt, __ is bound to load (filename) while the file is
being processed.
Examples:
(%i1) print ("I was called as", __);
I was called as print(I was called as, __)
(%o1) print(I was called as, __)
(%i2) foo (__); (%o2) foo(foo(__))
(%i3) g (x) := (print ("Current input expression =", __), 0);
(%o3) g(x) := (print("Current input expression =", __), 0)
(%i4) [aa : 1, bb : 2, cc : 3]; (%o4) [1, 2, 3]
(%i5) (aa + bb + cc)/(dd + ee + g(x));
cc + bb + aa
Current input expression = --------------
g(x) + ee + dd
6
(%o5) -------
ee + dd
_ is the most recent input expression (e.g., %i1, %i2,
%i3, …).
_ is assigned the input expression before the input is simplified or
evaluated. However, the value of _ is simplified (but not evaluated)
when it is displayed.
_ is recognized by batch and load. In a file processed
by batch, _ has the same meaning as at the interactive prompt.
In a file processed by load, _ is bound to the input expression
most recently evaluated at the interactive prompt or in a batch file; _
is not bound to the input expressions in the file being processed.
Examples:
(%i1) 13 + 29; (%o1) 42
(%i2) :lisp $_ ((MPLUS) 13 29)
(%i2) _; (%o2) 42
(%i3) sin (%pi/2); (%o3) 1
(%i4) :lisp $_ ((%SIN) ((MQUOTIENT) $%PI 2))
(%i4) _; (%o4) 1
(%i5) a: 13$ (%i6) b: 29$
(%i7) a + b; (%o7) 42
(%i8) :lisp $_ ((MPLUS) $A $B)
(%i8) _; (%o8) b + a
(%i9) a + b; (%o9) 42
(%i10) ev (_); (%o10) 42
% is the output expression (e.g., %o1, %o2, %o3,
…) most recently computed by Maxima, whether or not it was displayed.
% is recognized by batch and load. In a file processed
by batch, % has the same meaning as at the interactive prompt.
In a file processed by load, % is bound to the output expression
most recently computed at the interactive prompt or in a batch file; %
is not bound to output expressions in the file being processed.
In compound statements, namely block, lambda, or
(s_1, ..., s_n), %% is the value of the previous
statement.
At the first statement in a compound statement, or outside of a compound
statement, %% is undefined.
%% is recognized by batch and load, and it has the
same meaning as at the interactive prompt.
See also %.
Examples:
The following two examples yield the same result.
(%i1) block (integrate (x^5, x), ev (%%, x=2) - ev (%%, x=1));
21
(%o1) --
2
(%i2) block ([prev], prev: integrate (x^5, x),
ev (prev, x=2) - ev (prev, x=1));
21
(%o2) --
2
A compound statement may comprise other compound statements. Whether a
statement be simple or compound, %% is the value of the previous
statement.
(%i3) block (block (a^n, %%*42), %%/6);
n
(%o3) 7 a
Within a compound statement, the value of %% may be inspected at a break
prompt, which is opened by executing the break function. For example,
entering %%; in the following example yields 42.
(%i4) block (a: 42, break ())$ Entering a Maxima break point. Type 'exit;' to resume. _%%; 42 _
The value of the i’th previous output expression. That is, if the next
expression to be computed is the n’th output, %th (m) is the
(n - m)’th output.
%th is recognized by batch and load. In a file processed
by batch, %th has the same meaning as at the interactive prompt.
In a file processed by load, %th refers to output expressions most
recently computed at the interactive prompt or in a batch file; %th does
not refer to output expressions in the file being processed.
Example:
%th is useful in batch files or for referring to a group of
output expressions. This example sets s to the sum of the last five
output expressions.
(%i1) 1;2;3;4;5; (%o1) 1 (%o2) 2 (%o3) 3 (%o4) 4 (%o5) 5 (%i6) block (s: 0, for i:1 thru 5 do s: s + %th(i), s); (%o6) 15
As prefix to a function or variable name, ? signifies that the name is a
Lisp name, not a Maxima name. For example, ?round signifies the Lisp
function ROUND. See Lisp and Maxima for more on this point.
The notation ? word (a question mark followed a word, separated by
whitespace) is equivalent to describe("word"). The question mark must
occur at the beginning of an input line; otherwise it is not recognized as a
request for documentation. See also describe.
The notation ?? word (?? followed a word, separated by whitespace)
is equivalent to describe("word", inexact). The question mark must occur
at the beginning of an input line; otherwise it is not recognized as a request
for documentation. See also describe.
The dollar sign $ terminates an input expression,
and the most recent output % and an output label, e.g. %o1,
are assigned the result, but the result is not displayed.
See also ;.
Example:
(%i1) 1 + 2 + 3 $
(%i2) %; (%o2) 6
(%i3) %o1; (%o3) 6
The semicolon ; terminates an input expression,
and the resulting output is displayed.
See also $.
Example:
(%i1) 1 + 2 + 3; (%o1) 6
Default value: %i
inchar is the prefix of the labels of expressions entered by the user.
Maxima automatically constructs a label for each input expression by
concatenating inchar and linenum.
inchar may be assigned any string or symbol, not necessarily a single
character. Because Maxima internally takes into account only the first char of
the prefix, the prefixes inchar, outchar, and
linechar should have a different first char. Otherwise some commands
like kill(inlabels) do not work as expected.
See also labels.
Example:
(%i1) inchar: "input"; (%o1) input
(input2) expand((a+b)^3);
3 2 2 3
(%o2) b + 3 a b + 3 a b + a
Default value: []
infolists is a list of the names of all of the information
lists in Maxima. These are:
labelsAll bound %i, %o, and %t labels.
valuesAll bound atoms which are user variables, not Maxima options or switches,
created by : or :: or functional binding.
functionsarraysAll arrays, hashed arrays and memoizing functions.
macrosAll user-defined macro functions, created by ::=.
myoptionsAll options ever reset by the user (whether or not they are later reset to their default values).
rulesAll user-defined pattern matching and simplification rules, created
by tellsimp, tellsimpafter, defmatch, or
defrule.
aliasesAll atoms which have a user-defined alias, created by the alias,
ordergreat, orderless functions or by declaring the atom as a
noun with declare.
dependenciesAll atoms which have functional dependencies, created by the
depends, dependencies, or gradef functions.
gradefsAll functions which have user-defined derivatives, created by the
gradef function.
propsAll atoms which have any property other than those mentioned above, such as
properties established by atvalue or matchdeclare, etc.,
as well as properties established in the declare function.
structuresAll structs defined using defstruct.
let_rule_packagesAll 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.)
Removes all bindings (value, function, array, or rule) from the arguments
a_1, …, a_n. An argument a_k may be a symbol or a
single array element. When a_k is a single array element, kill
unbinds that element without affecting any other elements of the array.
Several special arguments are recognized. Different kinds of arguments
may be combined, e.g., kill (inlabels, functions, allbut (foo, bar)).
kill (labels) unbinds all input, output, and intermediate expression
labels created so far. kill (inlabels) unbinds only input labels which
begin with the current value of inchar. Likewise,
kill (outlabels) unbinds only output labels which begin with the current
value of outchar, and kill (linelabels) unbinds only
intermediate expression labels which begin with the current value of
linechar.
kill (n), where n is an integer,
unbinds the n most recent input and output labels.
kill ([m, n]) unbinds input and output labels m through
n.
kill (infolist), where infolist is any item in
infolists (such as values, functions, or
arrays) unbinds all items in infolist.
See also infolists.
kill (all) unbinds all items on all infolists. kill (all) does
not reset global variables to their default values; see reset on this
point.
kill (allbut (a_1, ..., a_n)) unbinds all items on all
infolists except for a_1, …, a_n.
kill (allbut (infolist)) unbinds all items except for the ones on
infolist, where infolist is values,
functions, arrays, etc.
The memory taken up by a bound property is not released until all symbols are unbound from it. In particular, to release the memory taken up by the value of a symbol, one unbinds the output label which shows the bound value, as well as unbinding the symbol itself.
kill quotes its arguments. The quote-quote operator ''
defeats quotation.
kill (symbol) unbinds all properties of symbol. In contrast,
the functions remvalue, remfunction,
remarray, and remrule unbind a specific property.
Note that facts declared by assume don’t require a symbol they apply to,
therefore aren’t stored as properties of symbols and therefore aren’t affected
by kill.
kill always returns done, even if an argument has no binding.
Returns the list of input, output, or intermediate expression labels which begin
with symbol. Typically symbol is the value of
inchar, outchar, or linechar.
If no labels begin with symbol, labels returns an empty list.
By default, Maxima displays the result of each user input expression, giving the
result an output label. The output display is suppressed by terminating the
input with $ (dollar sign) instead of ; (semicolon). An output
label is constructed and bound to the result, but not displayed, and the label
may be referenced in the same way as displayed output labels. See also
%, %%, and %th.
Intermediate expression labels can be generated by some functions. The option
variable programmode controls whether solve and some other
functions generate intermediate expression labels instead of returning a list of
expressions. Some other functions, such as ldisplay, always generate
intermediate expression labels.
See also inchar, outchar, linechar, and
infolists.
The variable labels is the list of input, output, and intermediate
expression labels, including all previous labels if inchar,
outchar, or linechar were redefined.
Default value: %t
linechar is the prefix of the labels of intermediate expressions
generated by Maxima. Maxima constructs a label for each intermediate expression
(if displayed) by concatenating linechar and linenum.
linechar may be assigned any string or symbol, not necessarily a single
character. Because Maxima internally takes into account only the first char of
the prefix, the prefixes inchar, outchar, and
linechar should have a different first char. Otherwise some commands
like kill(inlabels) do not work as expected.
Intermediate expressions might or might not be displayed.
See programmode and labels.
The line number of the current pair of input and output expressions.
Default value: []
myoptions is the list of all options ever reset by the user,
whether or not they get reset to their default value.
Default value: false
When nolabels is true, input and output result labels (%i
and %o, respectively) are displayed, but the labels are not bound to
results, and the labels are not appended to the labels list. Since
labels are not bound to results, garbage collection can recover the memory taken
up by the results.
Otherwise input and output result labels are bound to results, and the labels
are appended to the labels list.
Intermediate expression labels (%t) are not affected by nolabels;
whether nolabels is true or false, intermediate expression
labels are bound and appended to the labels list.
See also batch, load, and labels.
Default value: false
When optionset is true, Maxima prints out a message whenever a
Maxima option is reset. This is useful if the user is doubtful of the spelling
of some option and wants to make sure that the variable he assigned a value to
was truly an option variable.
Example:
(%i1) optionset:true; assignment: assigning to option optionset (%o1) true (%i2) gamma_expand:true; assignment: assigning to option gamma_expand (%o2) true
Default value: %o
outchar is the prefix of the labels of expressions computed by Maxima.
Maxima automatically constructs a label for each computed expression by
concatenating outchar and linenum.
outchar may be assigned any string or symbol, not necessarily a single
character. Because Maxima internally takes into account only the first char of
the prefix, the prefixes inchar, outchar and
linechar should have a different first char. Otherwise some commands
like kill(inlabels) do not work as expected.
See also labels.
Example:
(%i1) outchar: "output"; (output1) output
(%i2) expand((a+b)^3);
3 2 2 3
(output2) b + 3 a b + 3 a b + a
Displays input, output, and intermediate expressions, without recomputing them.
playback only displays the expressions bound to labels; any other output
(such as text printed by print or describe, or error messages)
is not displayed. See also labels.
playback quotes its arguments. The quote-quote operator ''
defeats quotation. playback always returns done.
playback () (with no arguments) displays all input, output, and
intermediate expressions generated so far. An output expression is displayed
even if it was suppressed by the $ terminator when it was originally
computed.
playback (n) displays the most recent n expressions.
Each input, output, and intermediate expression counts as one.
playback ([m, n]) displays input, output, and intermediate
expressions with numbers from m through n, inclusive.
playback ([m]) is equivalent to
playback ([m, m]); this usually prints one pair of input and
output expressions.
playback (input) displays all input expressions generated so far.
playback (slow) pauses between expressions and waits for the user to
press enter. This behavior is similar to demo.
playback (slow) is useful in conjunction with save or
stringout when creating a secondary-storage file in order to pick out
useful expressions.
playback (time) displays the computation time for each expression.
playback (grind) displays input expressions in the same format as the
grind function. Output expressions are not affected by the grind
option. See grind.
Arguments may be combined, e.g., playback ([5, 10], grind, time, slow).
Default value: _
prompt is the prompt symbol of the demo function,
playback (slow) mode, and the Maxima break loop (as invoked by
break).
Terminates the Maxima session. Note that the function must be invoked as
quit(); or quit()$, not quit by itself.
quit supports returning an exit code to the shell for Lisps and
OSes that support exit codes. The default exit code is 0 (usually
indicating no errors encountered). Thus quit(1) indicates to the
shell that maxima exited with some kind of failure. This is useful in
scripts where maxima can indicate to the shell that maxima failed to
compute something or some other bad thing happened.
To stop a lengthy computation, type control-C. The default action is to
return to the Maxima prompt. If *debugger-hook* is nil,
control-C opens the Lisp debugger. See also Debugging.
Prints expr_1, …, expr_n, then reads one expression from the
console and returns the evaluated expression. The expression is terminated with
a semicolon ; or dollar sign $.
See also readonly
Example:
(%i1) foo: 42$
(%i2) foo: read ("foo is", foo, " -- enter new value.")$
foo is 42 -- enter new value.
(a+b)^3;
(%i3) foo;
3
(%o3) (b + a)
Prints expr_1, …, expr_n, then reads one expression from the
console and returns the expression (without evaluation). The expression is
terminated with a ; (semicolon) or $ (dollar sign).
See also read.
Examples:
(%i1) aa: 7$
(%i2) foo: readonly ("Enter an expression:");
Enter an expression:
2^aa;
aa
(%o2) 2
(%i3) foo: read ("Enter an expression:");
Enter an expression:
2^aa;
(%o3) 128
Resets many global variables and options, and some other variables, to their default values.
reset processes the variables on the Lisp list
*variable-initial-values*. The Lisp macro defmvar puts variables
on this list (among other actions). Many, but not all, global variables and
options are defined by defmvar, and some variables defined by
defmvar are not global variables or options.
Default value: false
When showtime is true, the computation time and elapsed time is
printed with each output expression.
The computation time is always recorded, so time and playback can
display the computation time even when showtime is false.
See also timer.
Enters the Lisp system under Maxima. (to-maxima) returns to Maxima.
Example:
Define a function and enter the Lisp system under Maxima. The definition is
inspected on the property list, then the function definition is extracted,
factored and stored in the variable $result. The variable can be used in Maxima
after returning to Maxima.
(%i1) f(x):=x^2+x;
2
(%o1) f(x) := x + x
(%i2) to_lisp();
Type (to-maxima) to restart, ($quit) to quit Maxima.
MAXIMA> (symbol-plist '$f)
(MPROPS (NIL MEXPR ((LAMBDA) ((MLIST) $X)
((MPLUS) ((MEXPT) $X 2) $X))))
MAXIMA> (setq $result ($factor (caddr (mget '$f 'mexpr))))
((MTIMES SIMP FACTORED) $X ((MPLUS SIMP IRREDUCIBLE) 1 $X))
MAXIMA> (to-maxima)
Returning to Maxima
(%o2) true
(%i3) result;
(%o3) x (x + 1)
Sequentially read lisp forms from the string str and evaluate them. Any values produced from the last form are returned as a Maxima list.
Examples:
(%i1) eval_string_lisp ("");
(%o1) []
(%i2) eval_string_lisp ("(values)");
(%o2) []
(%i3) eval_string_lisp ("69");
(%o3) [69]
(%i4) eval_string_lisp ("1 2 3");
(%o4) [3]
(%i5) eval_string_lisp ("(values 1 2 3)");
(%o5) [1,2,3]
(%i6) eval_string_lisp ("(defun $foo (x) (* 2 x))");
(%o6) [foo]
(%i7) foo (5); (%o7) 10
See also eval_string.
Initial value: []
values is a list of all bound user variables (not Maxima options or
switches). The list comprises symbols bound by :, or ::.
If the value of a variable is removed with the commands kill,
remove, or remvalue the variable is deleted from
values.
See functions for a list of user defined functions.
Examples:
First, values shows the symbols a, b, and c, but
not d, it is not bound to a value, and not the user function f.
The values are removed from the variables. values is the empty list.
(%i1) [a:99, b:: a-90, c:a-b, d, f(x):=x^2];
2
(%o1) [99, 9, 90, d, f(x) := x ]
(%i2) values; (%o2) [a, b, c]
(%i3) [kill(a), remove(b,value), remvalue(c)]; (%o3) [done, done, [c]]
(%i4) values; (%o4) []
Next: Functions and Variables for Display, Previous: Introduction to Command Line, Up: Command Line [Contents][Index]