Interpolation and Regression are fundamental and important calculations in mathematics. Mr. Newton and Mr. Gauss were engaged in-depth with numerical solutions for these problems. Today, there are improved algorithms, that can solve such tasks.
isimSoftwareScientificGraphSoftware is a scientific graph software for data analysis and presentation. You can make 2D and 3D graphs quickly from data files in text format. This software is tiny but includes many basic functions to analyze/edit data as well as rather advanced ones.