Scilab Home page | Wiki | Bug tracker | Forge | Mailing list archives | ATOMS | File exchange
Please login or create an account
Change language to: English - Português - 日本語 - Русский

Please note that the recommended version of Scilab is 6.1.0. This page might be outdated.
See the recommended documentation of this function

Aide de Scilab >> Graphiques > 2d_plot > Sfgrayplot

# Sfgrayplot

smooth 2D plot of a surface defined by a function using colors

### Calling Sequence

```Sfgrayplot(x, y, f, <opt_args>)
Sfgrayplot(x, y, f [,strf, rect, nax, zminmax, colminmax, mesh, colout])```

### Arguments

x, y

real row vectors of size `n1` and `n2`.

f

a scilab function (`z=f(x,y)`).

<opt_args>

this represents a sequence of statements `key1=value1, key2=value2, ...` where `key1`, `key2, ...` can be one of the following: `strf`, `rect`, `nax`, `zminmax`, `colminmax`, `mesh`, `colout` (see plot2d for the 3 first and fec for the 4 last).

strf, rect, nax

see plot2d.

zminmax, colminmax, mesh, colout

see fec.

### Description

`Sfgrayplot` is the same as `fgrayplot` but the plot is smoothed. The function `fec` is used for smoothing. The surface is plotted assuming that it is linear on a set of triangles built from the grid (here with `n1=5`, `n2=3`):

```
_____________
| /| /| /| /|
|/_|/_|/_|/_|
| /| /| /| /|
|/_|/_|/_|/_|
```

The function colorbar may be used to see the color scale (but you must know (or compute) the min and max values).

Instead of `Sfgrayplot`, you can use Sgrayplot and this may be a little faster.

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

### Examples

```// example #1: plot 4 surfaces
function z=surf1(x, y), z=x*y, endfunction
function z=surf2(x, y), z=x^2-y^2, endfunction
function z=surf3(x, y), z=x^3+y^2, endfunction
function z=surf4(x, y), z=x^2+y^2, endfunction
clf()
set(gcf(),"color_map",[jetcolormap(64);hotcolormap(64)])
x = linspace(-1,1,60);
y = linspace(-1,1,60);
drawlater();
subplot(2,2,1)
colorbar(-1,1,[1,64])
Sfgrayplot(x,y,surf1,strf="041",colminmax=[1,64])
xtitle("f(x,y) = x*y")
subplot(2,2,2)
colorbar(-1,1,[65,128])
Sfgrayplot(x,y,surf2,strf="041",colminmax=[65,128])
xtitle("f(x,y) = x^2-y^2")
subplot(2,2,3)
colorbar(-1,2,[65,128])
Sfgrayplot(x,y,surf3,strf="041",colminmax=[65,128])
xtitle("f(x,y) = x^3+y^2")
subplot(2,2,4)
colorbar(0,2,[1,64])
Sfgrayplot(x,y,surf4,strf="041",colminmax=[1,64])
xtitle("f(x,y) = x^2+y^2")
drawnow();
show_window()```
```// example #2: plot surf3 and add some contour lines
function z=surf3(x, y), z=x^3+y^2, endfunction
clf()
x = linspace(-1,1,60);
y = linspace(-1,1,60);
set(gcf(),"color_map",hotcolormap(128))
drawlater();
colorbar(-1,2)
Sfgrayplot(x,y,surf3,strf="041")
contour2d(x,y,surf3,[-0.1, 0.025, 0.4],style=[1 1 1],strf="000")
xtitle("f(x,y) = x^3+y^2")
drawnow();
show_window()```
```// example #3: plot surf3 and use zminmax and colout optional arguments
//             to restrict the plot for -0.5<= z <= 1
function z=surf3(x, y), z=x^3+y^2, endfunction
clf()
x = linspace(-1,1,60);
y = linspace(-1,1,60);
set(gcf(),"color_map",jetcolormap(128))
drawlater();
zminmax = [-0.5 1]; colors=[32 96];
colorbar(zminmax(1),zminmax(2),colors)
Sfgrayplot(x, y, surf3, strf="041", zminmax=zminmax, colout=[0 0], colminmax=colors)
contour2d(x,y,surf3,[-0.5, 1],style=[1 1 1],strf="000")
xtitle("f(x,y) = x^3+y^2, with parts under z = -0.5 and upper z = 1 removed")
drawnow() ;
show_window()```

### See Also

• fec — dessin en pseudo-couleurs d'une surface définie sur un maillage constitué de polygones convexes
• fgrayplot — représentation 2D en pseudo-couleurs d'une surface définie par une fonction
• grayplot — 2D plot of a surface using colors
• Sgrayplot — smooth 2D plot of a surface using colors

### Comments

Add a comment:
Please login to comment this page.

 Report an issue << Matplot properties 2d_plot Sgrayplot >>

 Scilab EnterprisesCopyright (c) 2011-2017 (Scilab Enterprises)Copyright (c) 1989-2012 (INRIA)Copyright (c) 1989-2007 (ENPC)with contributors Last updated:Wed Apr 01 10:21:42 CEST 2015