Fudge Factor

A close cousin to the kludge and the jang.

Used especially often in the videogame industry.

"Just fudge it."

"Put in a fudge factor, and it'll be close enough."

"void PlayerTank::DriveForward(float acceleration, float driftFudgeFactor, float brakeFudgeFactor)"

I once had to write code to take latitude-longitude coordinates from a file and convert them to the coordinate system used by our GIS application. (For those of you unfamiliar with geographic coordinate systems: there are lots of different systems, they are all filled with special cases and rules, and lots of spherical and planar geometry comes into play.) I downloaded some Fortran code from the US Geological Survey site and ran it through f2c (Fortran-to-C) to give me C code that I could compile and link into our C++ application.

Unfortunately, each of the coordinates, which were supposed to correspond to roadway intersections, all transformed to be about two blocks too far to the north, and half a block too far to the west. I couldn't figure out if the error was due to (a) inaccurate input data, (b) errors in the conversion routine, (c) problems due to conversion from Fortran to C, (d) problems with floating-point accuracy, or (e) changes to the coordinate system definition (which they do every few decades). So, I just added a FudgeFactor and everything looked fine. I never felt good about it, but I had more important things to worry about.

Just off the top of my head, possible sources of error include (but are not limited to) WGS84 versus WGS72, using TransverseMercator? versus TangentPlane? or ConicalProjection?, and so on.