How to create a random 3d point cloud

% Initialization steps.
clc;    % Clear the command window.
fprintf('Beginning to run %s.m ...\n', mfilename);
close all;  % Close all figures (except those of imtool.)
clear;  % Erase all existing variables. Or clearvars if you want.
workspace;  % Make sure the workspace panel is showing.
format long g;
format compact;
fontSize = 15;
data = xlsread('data.xlsx')
x = data(:, 1);
y = data(:, 2);
z = data(:, 3);
hFig1 = figure;
plot3(x, y, z, 'b.-', 'MarkerSize', 20, 'LineWidth', 2);
xlabel('x', 'FontSize', fontSize);
ylabel('y', 'FontSize', fontSize);
zlabel('z', 'FontSize', fontSize);
grid on;
hFig1.WindowState = 'maximized';
% Now spline fit 1000 points in between.
hFig2 = figure;
xq = linspace(1, length(x), 1000);
xs = spline(1:length(x), x, xq);
yq = linspace(1, length(y), 1000);
ys = spline(1:length(y), y, yq);
zq = linspace(1, length(z), 1000);
zs = spline(1:length(z), z, zq);
% Plot them.
subplot(2, 1, 1);
plot(1 : length(x), x, 'r.', 'MarkerSize', 20);
hold on;
plot(1 : length(y), y, 'g.', 'MarkerSize', 20);
plot(1 : length(z), z, 'b.', 'MarkerSize', 20);
title('Original X, Y, and Z Values', 'FontSize', fontSize);
legend('x', 'y', 'z');
subplot(2, 1, 2);
plot(1 : length(xs), xs, 'r-', 'LineWidth', 2);
hold on;
plot(1 : length(ys), ys, 'g-', 'LineWidth', 2);
plot(1 : length(zs), zs, 'b-', 'LineWidth', 2);
grid on;
title('Spline Fits', 'FontSize', fontSize);
legend('x', 'y', 'z');
% Plot back on the main figure in red.
figure(hFig1);
hold on;
plot3(xs, ys, zs, 'r-', 'LineWidth', 2);
% Clip all values to no lower than 0.
xs = max(0, xs);
ys = max(0, ys);
zs = max(0, zs);
% Clip all values to no higher than 1.
xs = min(1, xs);
ys = min(1, ys);
zs = min(1, zs);
% Plot clipped range back on the main figure in magenta.
plot3(xs, ys, zs, 'm-', 'LineWidth', 2);
legend('Original Knots', 'Spline Fit', 'Clipped');
fprintf('Done running %s.m ...\n', mfilename);