Data Visualization with MATLAB

1. 2D Line Plot: plot(x, y)

The standard function for continuous 2D data visualization. Use line properties to customize colors, line width, and marker styles.

x = 0:0.1:2*pi;
y = sin(x);
plot(x, y, '-r*', 'LineWidth', 2, 'MarkerSize', 6);
xlabel('Angle (radians)');
ylabel('Amplitude');
title('Sine Wave Signal');
grid on;

2. Grid of Multiple Subplots: subplot(m, n, p)

Divide the figure window into an m-by-n matrix of smaller axes.

subplot(2,1,1);
plot(x, sin(x), 'b'); title('Sine'); grid on;

subplot(2,1,2);
plot(x, cos(x), 'r'); title('Cosine'); grid on;

3. Overlay Multiple Curves: hold on / hold off

x = 0:0.1:2*pi;
plot(x, sin(x), 'r-'); hold on;
plot(x, cos(x), 'b--'); hold off;
legend('sin(x)', 'cos(x)');
title('Sine & Cosine Comparison');

4. Scatter Plot: scatter(x, y, sz, c)

x = randn(100, 1);
y = randn(100, 1);
sz = 50; c = sqrt(x.^2 + y.^2);
scatter(x, y, sz, c, 'filled');
colorbar; title('2D Scatter Distribution');

5. Bar Chart: bar(y)

categories = {'Q1', 'Q2', 'Q3', 'Q4'};
sales = [150, 220, 180, 310];
bar(sales, 'FaceColor', [0.2 0.6 0.8]);
set(gca, 'XTickLabel', categories);
ylabel('Sales ($k)'); title('Quarterly Sales');

6. Discrete Stem Plot: stem(n, x)

n = 0:20;
x = (0.8).^n;
stem(n, x, 'filled', 'MarkerFaceColor', 'red');
xlabel('Sample Index n'); ylabel('x[n]');
title('Discrete Exponential Signal');

7. 3D Surface Plot: surf(X, Y, Z)

[X, Y] = meshgrid(-2:0.1:2, -2:0.1:2);
Z = X .* exp(-X.^2 - Y.^2);
surf(X, Y, Z); colorbar;
xlabel('X'); ylabel('Y'); zlabel('Z');
title('3D Mesh Surface Plot');

8. Histogram Data Distribution: histogram(data)

data = randn(1000, 1);
histogram(data, 30, 'FaceColor', 'g');
xlabel('Value'); ylabel('Frequency');
title('Normal Distribution Histogram');

9. Pie Chart: pie(data, explode)

data = [35, 25, 20, 20];
labels = {'EE', 'ME', 'CS', 'CE'};
explode = [1 0 0 0];
pie(data, explode, labels);
title('Engineering Major Share');

10. 3D Line Helix: plot3(x, y, z)

t = 0:pi/50:10*pi;
st = sin(t); ct = cos(t);
plot3(st, ct, t, 'LineWidth', 2);
grid on; xlabel('x'); ylabel('y'); zlabel('z');
title('3D Helix Curve');

11. 2D Contour Map: contourf(X, Y, Z)

[X, Y] = meshgrid(-3:0.125:3);
Z = peaks(X, Y);
contourf(X, Y, Z, 10); colorbar;
title('Filled 2D Contour Map');

12. Exporting Figures: saveas() & exportgraphics()

fig = gcf;
% Save high-res PNG
exportgraphics(fig, 'matlab_plot_output.png', 'Resolution', 300);
% Save vector PDF
saveas(fig, 'matlab_plot_output.pdf');