3.1 Documentation

The Maxima on-line user’s manual can be viewed in different forms. From the Maxima interactive prompt, the user’s manual is viewed as plain text by the ? command (i.e., the describe function). The user’s manual is viewed as info hypertext by the info viewer program and as a web page by any ordinary web browser.

example displays examples for many Maxima functions. For example,

(%i1) example (integrate);

yields

(%i2) test(f):=block([u],u:integrate(f,x),ratsimp(f-diff(u,x)))
(%o2) test(f) := block([u], u : integrate(f, x),
                                         ratsimp(f - diff(u, x)))
(%i3) test(sin(x))
(%o3)                           0
(%i4) test(1/(x+1))
(%o4)                           0
(%i5) test(1/(x^2+1))
(%o5)                           0

and additional output.

3.2 Functions and Variables for Help

Function: apropos (name) ¶

Searches for Maxima names which have name appearing anywhere within them; name must be a string or symbol. 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. So, if you can only remember part of the name of a Maxima command or variable, you can use this command to find the rest of the name. Similarly, you can type apropos (tr_) to find a list of many of the switches relating to the translator, most of which begin with tr_.

apropos("") returns a list with all Maxima names.

apropos returns the empty list [], if no name is found.

Example:

Show all Maxima symbols which have gamma in the name:

(%i1) apropos("gamma");
(%o1) [%gamma, Gamma, gamma_expand, gammalim, makegamma, 
prefer_gamma_incomplete, gamma, gamma-incomplete, gamma_incomplete, 
gamma_incomplete_generalized, gamma_incomplete_generalized_regularized, 
gamma_incomplete_lower, gamma_incomplete_regularized, log_gamma]

The same example, using the symbol gamma, rather than the string:

(%i2) apropos(gamma);
(%o2) [%gamma, Gamma, gamma_expand, gammalim, makegamma, 
prefer_gamma_incomplete, gamma, gamma-incomplete, gamma_incomplete, 
gamma_incomplete_generalized, gamma_incomplete_generalized_regularized, 
gamma_incomplete_lower, gamma_incomplete_regularized, log_gamma]

The number of symbols in the current Maxima session. This will vary.

(%i3) length(apropos(""));
(%o3)                                2338

Categories: Help ·

Function: demo (filename) ¶

Evaluates Maxima expressions in filename and displays the results. demo pauses after evaluating each expression and continues after the user enters a carriage return. (If running in Xmaxima, demo may need to see a semicolon ; followed by a carriage return.)

demo searches the list of directories file_search_demo to find filename. If the file has the suffix dem, the suffix may be omitted. See also file_search.

demo evaluates its argument. demo returns the name of the demonstration file.

Example:

(%i1) demo ("disol");

batching /home/wfs/maxima/share/simplification/disol.dem
 At the _ prompt, type ';' followed by enter to get next demo
(%i2)                      load("disol")

_
(%i3)           exp1 : a (e (g + f) + b (d + c))
(%o3)               a (e (g + f) + b (d + c))

_
(%i4)                disolate(exp1, a, b, e)
(%t4)                         d + c

(%t5)                         g + f

(%o5)                   a (%t5 e + %t4 b)

_

Categories: Help · Console interaction · File input ·

Function: describe
    describe (string)
    describe (string, exact)
    describe (string, inexact) ¶

describe(string) is equivalent to describe(string, exact).

describe(string, exact) finds an item with title equal (case-insensitive) to string, if there is any such item.

describe(string, inexact) finds all documented items which contain string in their titles. If there is more than one such item, Maxima asks the user to select an item or items to display.

At the interactive prompt, ? foo (with a space between ? and foo) is equivalent to describe("foo", exact), and ?? foo is equivalent to describe("foo", inexact).

describe("", inexact) yields a list of all topics documented in the on-line manual.

describe quotes its argument. describe returns true if some documentation is found, otherwise false.

To display the topics using a browser see output_format_for_help. Also see browser and url_base to configure how to display the HTML files.

See also Documentation.

Example:

(%i1) ?? integ
 0: Functions and Variables for Elliptic Integrals
 1: Functions and Variables for Integration
 2: Introduction to Elliptic Functions and Integrals
 3: Introduction to Integration
 4: askinteger  (Functions and Variables for Simplification)
 5: integerp  (Functions and Variables for Miscellaneous Options)
 6: integer_partitions  (Functions and Variables for Sets)
 7: integrate  (Functions and Variables for Integration)
 8: integrate_use_rootsof  (Functions and Variables for
    Integration)
 9: integration_constant_counter  (Functions and Variables for
    Integration)
 10: nonnegintegerp  (Functions and Variables for linearalgebra)
Enter space-separated numbers, `all' or `none': 7 8

 -- Function: integrate (<expr>, <x>)
 -- Function: integrate (<expr>, <x>, <a>, <b>)
     Attempts to symbolically compute the integral of <expr> with
     respect to <x>.  `integrate (<expr>, <x>)' is an indefinite
     integral, while `integrate (<expr>, <x>, <a>, <b>)' is a
     definite integral, [...]
     
 -- Option variable: integrate_use_rootsof
     Default value: `false'

     When `integrate_use_rootsof' is `true' and the denominator of
     a rational function cannot be factored, `integrate' returns
     the integral in a form which is a sum over the roots (not yet
     known) of the denominator.
     [...]

In this example, items 7 and 8 were selected (output is shortened as indicated by [...]). All or none of the items could have been selected by entering all or none, which can be abbreviated a or n, respectively.

Categories: Help · Console interaction ·

Option variable: output_format_for_help ¶

Default value: text

output_format_for_help controls how describe displays help.

output_format_for_help can be set to one of the following values:

text

Help is displayed as plain text sent to a terminal. This is the default.

html

Help is displayed using a browser to display the HTML version of the manual.

frontend

Help is displayed using the frontend’s help system. If no frontend is running then an error is signaled. For example, wxMaxima and xmaxima are some frontends for maxima.

Any other value is a error.

See also browser, and url_base.

Categories: Help · Global variables ·

Option variable: browser ¶

This specifies the command to use to open an HTML file. This is a format string of the form <cmd> ~A where ~A is replaced by the URL of the HTML file and <cmd> is some program that takes an arg and opens up a browser to the given URL.

On windows, the default setting is "start ~A", which uses the default browser to display the html file. You may replace it with e.g. start firefox ~A, start chrome ~A or start iexplore ~A if you want to use Firefox, Chrome, or Internet Explorer instead of the default browser.

On other OSes, the user’s default browser should be used automatically (using xdg-open on Linux/Unix and open on MacOS). You can also set the browser variable to use a non default browser, e.g. browser:"firefox '~A'"; or browser:"chromium '~A'";

See also output_format_for_help, and url_base.

Categories: Help · Global variables ·

Option variable: url_base ¶

When displaying help using a browser, url_base defines the URL to use. It defaults to a file:// path pointing to the directory containing the html files for documentation. However, you could use http://localhost:8080/ or some other URL that has the HTML help files. But this requires those URLs to have exactly the same HTML files in the info directory because a table is needed to translate a topic to the appropriate location in an html file.

See also output_format_for_help and browser.

Categories: Help · Global variables ·

Function: example
    example (topic)
    example () ¶

example (topic) displays some examples of topic, which is a symbol or a string. To get examples for operators like if, do, or lambda the argument must be a string, e.g. example ("do"). example is not case sensitive. Most topics are function names.

example () returns the list of all recognized topics.

The name of the file containing the examples is given by the global option variable manual_demo, which defaults to "manual.demo".

example quotes its argument. example returns done unless no examples are found or there is no argument, in which case example returns the list of all recognized topics.

Examples:

(%i1) example(append);
(%i2) append([y+x,0,-3.2],[2.5e+20,x])
(%o2)             [y + x, 0, - 3.2, 2.5e+20, x]
(%o2)                         done

(%i3) example("lambda");
(%i4) lambda([x,y,z],x^2+y^2+z^2)
                                    2    2    2
(%o4)            lambda([x, y, z], x  + y  + z )
(%i5) %(1,2,a)
                              2
(%o5)                        a  + 5
(%i6) 1+2+a
(%o6)                         a + 3
(%o6)                         done

Categories: Help · Console interaction ·

Option variable: manual_demo ¶

Default value: "manual.demo"

manual_demo specifies the name of the file containing the examples for the function example. See example.

Categories: Help · Global variables ·