Month: October 2014

Lambert’s Problem

Lambert’s problem is to solve for the orbit transfer that connects two position vectors in a given time of flight.  It is one of the basic problems of orbital mechanics, and was solved by Swiss mathematician Johann Heinrich Lambert. A standard

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Fortran & C Interoperability

The ISO_C_BINDING intrinsic module and the BIND attribute introduced in Fortran 2003 are very handy for producing standard and portable Fortran code that interacts with C code. The example given here shows how to use the popen, fgets, and pclose routines

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Midpoint Circle Algorithm

The Midpoint circle algorithm is a clever and efficient way of drawing a circle using only addition, subtraction, and bit shifts.  It is based on the Bresenham line algorithm developed by Jack Bresenham in 1962 at IBM. The algorithm was also independently discovered by

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