This is a full web-based CAS.
It does not need any server,
all the computations are done locally with the javascript
engine of your browser (requires Firefox version 19 or later,
or Safari,
the latest version of Firefox is recommended for good performances).
The code of the CAS is 12M, it is downloaded once then kept in your
browser cache
(giac.js javascript
compiled from native Giac/Xcas by emscripten).
The javascript code is at least 2 times slower than the native
code, and sometimes much slower (e.g. 8 times slower
for computing a Groebner basis like cyclic7). Most of the time
it is fast enough,
but it is recommended to run large computations with
Xcas!
Giac/Xcas, (c) B. Parisse, R. De Graeve, Institut Fourier,
Université de Grenoble I., licensed under the GPL3, for commercial
licenses contact us.
Program editor CodeMirror,
Initial Mathml and SVG code by J.P. Branchard.
Xcas manuals
A typical Xcas session will consist in entering commandlines that will
appear in the history. Sometimes you will also edit an already entered
command and reevaluate it.
The screen is divided in
A panel of buttons to load a session, see manuals and
configure. Once the history is non empty, additional buttons appear:
save or export session, a link that you can hit to e-mail or clone a session
(for example if your session crashed) or copy/paste, history/trash
and variables handling.
You can partially open an existing PC Xcas session from the File, Clone
menu of the Xcas program (or xcas --online filename.xws).
The help area where you will find short descriptions of
commands you asked for.
The history (empty when you start) divided into levels. You can
move level up and down (button at the left). You can edit a level
and reevaluate it (press Enter). You can move one level to the
trash (press backspace button at the right), and empty the trash
or recover levels in the trash (panel of buttons above).
A commandline with buttons that will help you fill the
commandline. You can show a scientific or/and tool keyboard (press the
123 or menu button), then move the mouse near a button to have
a short explanation on the corresponding command. You can enter
the beginning of a command then press Tab or hit the ? button, this
will show completions in the history. If you entered a valid Xcas command,
a short online help will be displayed with examples, hit the
corresponding buttons to copy one example, modify arguments and hit
Enter to run the commandline.
Example of simple computation 1/2+1/3 or sin(pi/4)
or sin(pi/4.0).
Example of CAS computation, press menu then
factor then ?, observe the online help on the top
of the page, you can click one example and modify it or just enter
your expression to factor like x^4-1, then press Enter.
Additionnaly, inside Firefox on a PC, right-click will show a
menu of many Xcas commands. See also below
for a few examples.
A console, with messages from the CAS : parse errors or while
running step by step commands like derivative. You can clear the console
and control the height of the console.
a Graph3d button to show or hide controls for the 3d graph
canvas.
Algebra : You can expand an expression with
for example .
Conversely,
or
factors an expression (like )
over Q or Q[i].
simplify(sin(3x)/sin(x)); gcd(x^4-1,x^3-1)
Some features are disabled by default on mobile devices.
Note also that Chrome mobile (default
browser on Android devices) is much
slower than Firefox (about 5 times slower), it freezes about ten seconds during
the first evaluation. Moreover Chrome does not support mathml
natively, it requires Mathjax to display 2d formula, this requires
net access and works only if Xcas is installed on the device.
It is highly recommended to download Firefox and run Xcas from Firefox.
If you want to install Xcas on your device, unzip
xcashtml.zip and search
xcasen.html, from
here (Android).
On mobile devices, the builtin keyboard delete key is incompatible
with the commandline, please use the del key above.
Variables
History
Trash
New function
function name
list of arguments
local variables
returned value