Scilab Function

fcontour - level curves on a 3D surface defined by a function

### Calling Sequence

  `fcontour(xr,yr,f,nz,[theta,alpha,leg,flag,ebox,zlev])`
  `fcontour(xr,yr,f,nz,<opt_args>)`

### Parameters

- `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 `contour` .
- `nz,` : see `contour` .
- `theta,alpha,leg,flag,ebox,zlev` : see `contour` .
- `<opt_args>` : see `contour` .

### Description

Draws level curves of a surface `z=f(x,y)` . The level curves are drawn on a 3D surface. The surface is given by the external function `f` . See `contour` .

The optional arguments `theta,alpha,leg ,flag,ebox, zlev` , can be passed by a sequence of statements `key1=value1, key2=value2` ,

`flag` ,`ebox` ,`zlev` . In this case, the order has no special meaning.

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 `fcontour()` to see a demo.

### Examples

    deff("[z]=surf(x,y)","z=sin(x)*cos(y)");
    t=%pi*[-10:10]/10;

    fcontour(t,t,surf,10)

    xbasc();fcontour(t,t,surf,10,ebox=[-4 4 -4 4 -1 1],zlev=-1,flag=[0 1 4])

### See Also

`contour` , `contour2d` , `fcontour2d` ,

### Author

J.Ph.C.