Help
How to Use
- Select a preset transformation or enter custom matrix values
- Choose a shape to transform
- Click "Apply Transformation" for instant result or "Animate" for smooth transition
- Toggle grid and original shape visibility
Understanding the Matrix
The 2×2 matrix [a,b; c,d] transforms point (x,y) to:
new_x = a×x + b×y
new_y = c×x + d×y
Matrix columns show where basis vectors (1,0) and (0,1) move to.
Transformation Types
- Identity: No change [1,0; 0,1]
- Rotation: Rotates around origin [cos θ, -sin θ; sin θ, cos θ]
- Scaling: Stretches axes [sx, 0; 0, sy]
- Shear: Slants shape [1, k; 0, 1] or [1, 0; k, 1]
- Reflection: Flips across axis, det = -1
- Projection: Collapses dimension, det = 0
Determinant and Area
The determinant tells you how area changes:
- det = 0: Collapses to a line
- |det| = 1: Preserves area
- |det| > 1: Expands area
- |det| < 1: Contracts area
- det < 0: Reverses orientation (reflection)
Composition of Transformations
To apply multiple transformations, multiply their matrices.
Important: Order matters! The rightmost matrix applies first.
Example: To rotate then scale, compute Scale × Rotation
Grid Visualization
The grid shows how the transformation warps space:
- Straight lines stay straight (fundamental property of linear transformations)
- Grid spacing shows local stretching/compression
- Grid orientation shows rotation and shearing