comet3d

Parameters

x

a real vector or matrix. If omitted, it is assumed to be the vector 1:nz where nz is the number of curve points given by the z parameter.

y

a real vector or matrix. If omitted, it is assumed to be the vector 1:nz where nz is the number of curve points given by the z parameter.

z

a real vector of length nz or a matrix with nz rows.

p

a real scalar in the interval[0 1[. Default value is 0.1.

fun

a scilab function with syntax z=fun(x,y).

c

a vector of ny color index.

Description

If (x,y,z) are three vectors with the same number of elements, this function draws a 3D comet animated plot. The plot is made of three parts:

ahead mark that shows the current (x(i),y(i),z(i)) position.

abody that shows the trailing curve that follows the head: the (x(i-k:i),y(i-k:i),z(i-k:i))) part of the curve.

atail that shows the (x(1:i-k),y(1:i-k),z(1:i-k)) part of the curve.

if z is a matrix and (x,y) are vectors then animated curves are drawn for each triple (x,y,z(:,l)). in this case nz is the number of rows of z.

if x,y,z are matrices with the same dimensions then animated curves are drawn for each triple (x(:,l),y(:,l),z(:,l)).

comet3d(x,y,fun,...) computes the z vector as z(i)=fun(x(i),y(i))

comet3d(...,p) can be used to set the relative length of the body. k is defined as k = round(p*nz).

Examples

t = linspace(-%pi,%pi,500);
clf
comet3d(sin(5*t), sin(t), t.^2)

t = linspace(-%pi,%pi,500)';
clf
comet3d(sin(5*t), sin(t), [t.^2,ones(t)])

t = linspace(-%pi,%pi,500)';
function z=traj(x, y),z=1.5*sin(x^2)*cos(y),endfunction
clf
comet3d(cos(t), sin(t), traj)

See also

• comet — 2D comet animated plot.

History