Hindawi Publishing Corporation Journal of Applied Mathematics Volume 2012, Article ID 247120, 19 pages doi:10.1155/2012/247120 Research Article Positive Data Visualization Using Trigonometric Function Farheen Ibraheem, 1 Maria Hussain, 2 Malik Zawwar Hussain, 3 and Akhlaq Ahmad Bhatti 1 1 National University of Computer and Emerging Sciences, Lahore 54000, Pakistan 2 Lahore College for Women University, Lahore 54500, Pakistan 3 Department of Mathematics, University of the Punjab, Lahore 54590, Pakistan Correspondence should be addressed to Farheen Ibraheem, farheen.butt@gmail.com Received 6 June 2012; Revised 20 September 2012; Accepted 4 October 2012 Academic Editor: Kai Diethelm Copyright q 2012 Farheen Ibraheem et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. A C 1 piecewise rational trigonometric cubic function with four shape parameters has been constructed to address the problem of visualizing positive data. Simple data-dependent constraints on shape parameters are derived to preserve positivity and assure smoothness. The method is then extended to positive surface data by rational trigonometric bicubic function. The order of approximation of developed interpolant is Oh 3 i . 1. Introduction Data visualization is the mechanism to communicate information by means of graphs, images, diagrams, and animations. It is extensively used in interactive simulation, geomet- rical design, geometric modeling, and computer-aided geometric design. It is an efficacious way to abridge complexity of data and facilitates prompt understanding of data. The three significant features of data are convexity, monotonicity, and positivity. Either of these features arises in the data whether it is a result of physical process or chemical exper- iment, and so forth. Plenty of spline functions exist which can produce smooth and visibly pleasant curves but incapable to visualize the inherited shape convexity, monotonicity, and positivity of given data. In this paper, the positive data visualization of both curve and surface data is addressed by a rational trigonometric cubic function. The objective of this paper is to preserve duly emphasized characteristic of data that is, positivity. Asim and Brodlie 1 developed a piecewise rational cubic function to preserve the positivity of positive data. In 1, if the interpolating function did not preserve the positivity in a subinterval, then the authors inserted extra knot to improve this matter. Butt