Scilab Function

fcontour2d - level curves of a surface defined by a function on a 2D plot

### Sequence d'appel

  `fcontour2d(xr,yr,f,nz,[style,strf,leg,rect,nax])`
  `fcontour2d(xr,yr,f,nz,<opt_args>)`

### Parametres

- `xr,yr` : two real row vectors of size n1 and n2.
- `f` : is an external which defines the surface `z=f(x,y)`. It is first computed on the grid specified by `xr,yr`. Then, control is passed to the routine `contour2d`.
- `nz` : the level values or the number of levels.

- `-` If `nz` is an integer, its value gives the number of level curves equally spaced from zmin to zmax.
- `-` If `nz` is a vector, `nz(i)` gives the value of the ith level curve.

<opt_args> : This represents a sequence of statements `key1=value1, key2=value2`,... where `key1`, `key2,...` can be one of the following: style, leg, rect, nax, strf or axesflag and frameflag (see plot2d)

- `[style,strf,leg,rect,nax]` : see `contour2d`.

### Description

Draws level curves of a surface `z=f(x,y)`. The level curves are drawn on a 2D plot. The surface is given by the external function `f`. See `contour2d`.

You can change the format of the floating point number printed on the levels by using `xset("fpf",string)` where `string` gives the format in C format syntax (for example `string="%.3f"`). Use `string=""` to switch back to default format and Use `string=" "` to suppress printing.

Enter the command `fcontour2d()` to see a demo.

### Exemples

    deff('z=surf(x,y)','z=x^4-y^4')
    x=-3:0.1:3;
    y=x;
    fcontour2d(x,y,surf,10);

### Voir aussi

`contour` `contour2d` `fcontour`

### Auteur

J.Ph.C.