 <p>Look for sources titled "C for Scientists" or "C for engineers". The first google hit contains answers to your questions: (<a href="http://www2.warwick.ac.uk/fac/sci/physics/current/teach/module_home/px270/week2/week_2a.pdf" rel="nofollow">http://www2.warwick.ac.uk/fac/sci/physics/current/teach/module_home/px270/week2/week_2a.pdf</a>).</p> <hr> <p>Have also a look at (<a href="http://sccn.ucsd.edu/labinfo/computer-faq/Numerical_Recipes.html" rel="nofollow">http://sccn.ucsd.edu/labinfo/computer-faq/Numerical_Recipes.html</a>), your paths may be different.</p>