If you define a function in a header file (i.e. have it’s implementation in the header) and statically link your program, you need to declare it inline if the header is used in multiple files. This is different from issues you get when a header file is included multiple times in a compilation unit. Consider… Read More static linking, duplicate symbol error and inlineing
Mixing up units is a very common problem everywhere. A formula takes meters, you put in feet and your Mars probe crashes. It happens. In C++ there are “zero cost” libraries to handle full-fledged dimensional checking, conversions and safeguards. How do they work? Are they really zero cost? Let’s explore using a simple limited example,… Read More Simple units checking for cheap in C++
Digital Apollo is a excellent sociological and technological study of the uneasy alliance between the astronauts who commanded the Apollo missions, and the computers which actually controlled the spacecraft systems. It traces how pilots, who first resisted the incursion of computers into their domain, gradually and grudgingly accepted the important role the computers played in… Read More Digital Apollo – Mindell (2008)
Currently, robotic spacecraft give us enormously more scientific and engineering value than manned missions. We should only invest in manned space flight once there is a clear rationale for a continuous manned presence in space. When Boeing figured out that bad time data caused Starliner to waste precious propellant during orbit insertion, making it infeasible… Read More We should not be wasting money on manned space missions.
In my earlier post I left off with the suggestion that I would get the Olympus 45mm f1.8 lens. I got a bit side tracked by an adventure with a Nikon F mount adapter, but I’m back now and I have a completely different plan. I abandoned my idea of getting a longer focal length… Read More Picking a prime for the 4/3 (Pt II)
While trying to figure out if I should splurge on a new lens for my E-M10 I re-discovered the joys of my old Nikon lenses thanks to a $16 adapter and the magic of my E-M10. SLR lenses on mirrorless micro 4/3 cameras are an especially good marriage because of the small flange distance of… Read More Old school on the E-M10
I don’t know how to play an instrument. I can’t read musical notation. I can’t sing or whistle. But when we got a piano in our home, I dared to dream that I could one day learn to play on it. So, how to start? A friend said “Hire a piano teacher.” That’s probably what anyone… Read More Learning piano