HAND_DATA
Numerical Exercises Using the Shape of a Hand

HAND_DATA is a set of MATLAB programs which carry out some numerical exercises based on data that came from tracing several points on a person's hand.

The original proposer of this exercise was Cleve Moler, in the textbook Numerical Computing with MATLAB.

Related Data and Programs:

CONVEX_HULL, a MATLAB program which demonstrates the computation of the convex hull of a set of 2D points.

POLYGON, a dataset directory which contains examples of polygons.

TRIANGULATE, a MATLAB program which triangulates a polygonal region.

Reference:

• Cleve Moler,
  Numerical Computing with MATLAB,
  SIAM, 2004,
  ISBN13: 978-0-898716-60-3,
  LC: QA297.M625.

Source Code:

• hand_acquire.m guides a user through the steps of recording hand data from the screen.
• hand_plot.m plots the hand data after it has been acquired.

Examples and Tests:

• hand_data.png, an image of hand data.
• x.txt, the X coordinates of a hand.
• y.txt, the Y coordinates of a hand.
• hand_nodes.txt, the X and Y coordinates of a hand in a single file.

The CONVEX_HULL program demonstrates how the computation of the convex hull of the hand data.

• convex_hull.m, a program to compute the convex hull.
• hand_hull.png, a PNG image.

The SPLINE program demonstrates how the X and Y hand data can be used to generate smooth spline functions X(T), Y(T) which can be plotted to yield a smooth looking curve.

• hand_spline.m, computes and plots the spline functions.
• hand_spline.png, a PNG image.

The TRANSFORMATION programs demonstrate linear transformations applied to the hand data.

• hand_dilation.m, dilates the data.
• hand_dilation.png, a PNG image.
• hand_linear.m, computes xy2 = A * xy + b for general A and b.
• hand_linear.png, a PNG image.
• hand_negation.m, computes xy2 = - xy.
• hand_negation.png, a PNG image.
• hand_reflection.m, computes xy2 and xy3 as x and y reflections of the data.
• hand_reflection.png, a PNG image.
• hand_rotation.m, computes xy2 = A*xy where A is a rotation matrix.
• hand_rotation.png, a PNG image.
• hand_translation.m, computes xy2 = xy + b.
• hand_translation.png, a PNG image.

The TRIANGULATE program can be used to triangulate the hand.

• hand_triangulated.png, a PNG image of the triangulated polygon.
• hand_elements.txt, the output file of triangles that make up the polygon.

You can go up one level to the MATLAB source codes.