Code 1 below is an example Scilab script that produces an animation of a point moving along x-axis.
// animation_point.sce
clear; xdel(winsid());
// Create motion data -- (1)
t = 0:0.001:1; // Time data
x = sin(2*%pi*t); // Position data
// Draw initial figure -- (2)
h_fig = figure;
h_fig.background = 8;
h_point = plot(x(1), 0, 'Marker', 'o', 'MarkerSize', 20,..
'MarkerEdgeColor', 'blue', 'MarkerFaceColor', 'blue');
h_axes = gca();
h_axes.data_bounds = [-1.5, -1.5; 1.5, 1.5];
// Animation Loop -- (3)
for i = 1:length(x)
drawlater();
h_point.data = [x(i), 0];
drawnow();
end
First at (1), the motion data of the point are created. Next at (2), the initial point is drawn by the plot command and the handle of the Polyline object is saved in the variable h_point. Finally in the loop at (3), the value of data property of the Polyline object is replaced and the figure is updated with drawnow() command resulting in animation. This is the basic code to make an animation in Scilab.
The animation produced by this script is shown in Movie 1.
In order to control the speed of the animation, realtime() can be used. Code 2 below creates an animation of a moving point as in Code 1, but controls the speed of the animation by calling realtime() in the loop.
// animation_point_with_realtime.sce clear; xdel(winsid()); // Create motion data -- (1) t = 0:0.01:1; // Time data x = sin(2*%pi*t); // Position data // Draw initial figure -- (2) h_fig = figure; h_fig.background = 8; h_point = plot(x(1), 0, 'Marker', 'o', 'MarkerSize', 20,.. 'MarkerEdgeColor', 'blue', 'MarkerFaceColor', 'blue'); h_axes = gca(); h_axes.data_bounds = [-1.5, -1.5; 1.5, 1.5]; // Animation Loop -- (3) realtimeinit(0.1); // set time unit duration, in seconds realtime(0); // set current time to 0 for i = 1:length(x) drawlater(); h_point.data = [x(i), 0]; realtime(i); // wait until i time units (0.1*i seconds) drawnow(); end
realtime()
