plot3d1

Arguments

x,y

row vectors of sizes n1 and n2 (x-axis and y-axis coordinates). These coordinates must be monotone.

z

matrix of size (n1,n2). z(i,j) is the value of the surface at the point (x(i),y(j)).

xf,yf,zf

matrices of size (nf,n). They define the facets used to draw the surface. There are n facets. Each facet i is defined by a polygon with nf points. The x-axis, y-axis and z-axis coordinates of the points of the ith facet are given respectively by xf(:,i), yf(:,i) and zf(:,i).

<opt_args>

This represents a sequence of statements key1=value1, key2=value2,... where key1, key2,... can be one of the following: theta, alpha ,leg,flag,ebox (see definition below).

theta, alpha

real values giving in degree the spherical coordinates of the observation point.

leg

string defining the labels for each axis with @ as a field separator, for example "X@Y@Z".

flag

a real vector of size three. flag=[mode,type,box].

mode

an integer (surface color).

mode>0

the surface is painted with color "mode" ; the boundary of the facet is drawn with current line style and color.

mode=0:

a mesh of the surface is drawn.

mode<0:

the surface is painted with color "-mode" ; the boundary of the facet is not drawn.

Note that the surface color treatement can be done using color_mode and color_flag options through the surface entity properties (see surface_properties).

type

an integer (scaling).

type=0:

the plot is made using the current 3D scaling (set by a previous call to param3d, plot3d, contour or plot3d1).

type=1:

rescales automatically 3d boxes with extreme aspect ratios, the boundaries are specified by the value of the optional argument ebox.

type=2:

rescales automatically 3d boxes with extreme aspect ratios, the boundaries are computed using the given data.

type=3:

3d isometric with box bounds given by optional ebox, similarily to type=1.

type=4:

3d isometric bounds derived from the data, to similarilytype=2.

type=5:

3d expanded isometric bounds with box bounds given by optional ebox, similarily to type=1.

type=6:

3d expanded isometric bounds derived from the data, similarily to type=2.

Note that axes boundaries can be customized through the axes entity properties (see axes_properties).

box

an integer (frame around the plot).

box=0:

nothing is drawn around the plot.

box=1:

unimplemented (like box=0).

box=2:

only the axes behind the surface are drawn.

box=3:

a box surrounding the surface is drawn and captions are added.

box=4:

a box surrounding the surface is drawn, captions and axes are added.

Note that axes aspect can also be customized through the axes entity properties (see axes_properties).

ebox

It specifies the boundaries of the plot as the vector [xmin,xmax,ymin,ymax,zmin,zmax]. This argument is used together with type in flag : if it is set to 1, 3 or 5 (see above to see the corresponding behaviour). If flag is missing, ebox is not taken into acoount.

Note that, when specified, the ebox argument acts on the data_bounds field that can also be reset through the axes entity properties (see axes_properties).

Description

plot3d1 plots a surface with colors depending on the z-level of the surface. This special plot function can also be enabled setting color_flag=1 after a plot3d (see surface_properties)

Enter the command plot3d1() to see a demo.

Examples

// simple plot using z=f(x,y) 
t=[0:0.3:2*%pi]'; z=sin(t)*cos(t'); 
plot3d1(t,t,z) 
// same plot using facets computed by genfac3d 
[xx,yy,zz]=genfac3d(t,t,z); 
clf(); 
plot3d1(xx,yy,zz) 
// multiple plots 
clf(); 
plot3d1([xx xx],[yy yy],[zz 4+zz]) 
// simple plot with viewpoint and captions 
clf() ;
plot3d1(1:10,1:20,10*rand(10,20),35,45,"X@Y@Z",[2,2,3]) 
// same plot without grid 
clf() 
plot3d1(1:10,1:20,10*rand(10,20),35,45,"X@Y@Z",[-2,2,3]) 
// plot of a sphere using facets computed by eval3dp 
deff("[x,y,z]=sph(alp,tet)",["x=r*cos(alp).*cos(tet)+orig(1)*ones(tet)";.. 
"y=r*cos(alp).*sin(tet)+orig(2)*ones(tet)";.. 
"z=r*sin(alp)+orig(3)*ones(tet)"]); 
r=1; orig=[0 0 0]; 
[xx,yy,zz]=eval3dp(sph,linspace(-%pi/2,%pi/2,40),linspace(0,%pi*2,20)); 
clf() 

plot3d(xx,yy,zz)
e=gce();
e.color_flag=1;
scf(2);
plot3d1(xx,yy,zz) // the 2 graphics are similar

See Also

• plot3d — 3D plot of a surface
• gca — Return handle of current axes.
• gce — Get current entity handle.
• scf — set the current graphic figure (window)
• clf — clear or reset the current graphic figure (window) to default values

Authors

J.Ph.C.