Session_Xcas

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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.

Configuration

Digits: Autosimplify:
, , , ,
, , ,
History x Output x
Documentation online

Xcas manuals

- Reference : hard disk, Internet,

| ### Session
Previous session inputs or evaluation session

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.

Examples of input:

- 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)`
- Solve equations : `solve(x^2-3*x+2=0); csolve(x^2=2*i); solve([x+y=1,x-y=3],[x,y])`
- Calculus : `f(x):=sin(x^2):; f(sqrt(pi)); f'(2); f'(y)
  int(1/(x^4-1)); int(1/(x^4+1)^4,x,0,+infinity)
  limit(sin(x)/x,x=0); series(sin(x),x=0,5);`
- Linear algebra : `A:=[[1,2],[3,4]]; inv(A); det(A-x*idn(A)); A[0,0]; rref(A); eigenvalues(A); eigenvectors(A);`
- Plots : `plot([sin(x),x-x^3/3!],x=-3..3,color=[red,blue])
  plotfunc(x^2-y^2,[x=-2..2,y=-2..2]); plane(z=0,color=cyan+filled);`

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 f
list of arguments x,y
local variables z
returned value z

Console

Downloading...