Scilab Function
Last update : 00/00/0000

champ - 2D vector field plot

### Calling Sequence

  `champ(x,y,fx,fy,[arfact,rect,strf])`
  `champ(x,y,fx,fy,<opt_args>)`

### Parameters

- `x,y`: two vectors which define the grid.
- `fx`: a matrix which describes the x component of the vector field. `fx(i,j)` is the x component of the vector field at point `(x(i),y(j))`.
- `fy`: a matrix which describes the y component of the vector field. `fy(i,j)` is the y component of the vector field at point `(x(i),y(j))`.
- `<opt_args>`: This represents a sequence of statements `key1=value1,key2=value2`,... where `key1`, `key2,...` can be one of the following: arfact, rect, strf (see below).
- `arfact`: an optional argument of type real which gives a scale factor for the display of the arrow heads on the plot (default value is 1.0).
- `rect`: a vector `rect=[xmin,ymin,xmax,ymax]` which gives the boundaries of the graphics frame to use.
- `strf`: a string of length 3 "xyz" which has the same meaning as the `strf` parameter of `plot2d`. The first character x has no effect with `champ`.

### Description

`champ` draws a 2D vector field. The length of the arrows is proportional to the intensity of the field.

If you want colored arrows with the color of the arrows depending on the intensity of the field, use `champ1`.

Enter the command `champ()` to see a demo.

### Examples

    // using rect as plot boundaries
    champ(-5:5,-5:5,rand(11,11),rand(11,11),rect=[-10,-10,10,10],arfact=2)
    // using (x,y) to get boundaries
    clf()
    champ(-5:5,-5:5,rand(11,11),rand(11,11),2,[-10,-10,10,10],"021")

### See Also

`champ1`, `fchamp`, `plot2d`,

### Author

J.Ph.C.