I would say that a checksum is necessarily a hashcode. However, not all hashcodes make good checksums. A checksum has a special purpose — it verifies or checks the integrity of data (some can go beyond that by allowing for error-correction). “Good” checksums are easy to compute, and can detect many types of data corruptions … Read more
LabVIEW 51 nodes, 5 structures, 10 diagrams Teaching the elephant to tap-dance is never pretty. I’ll, ah, skip the character count. The program flows from left to right:
Read this line, and do what it says twice.
See: RFC 3092: Etymology of “Foo”, D. Eastlake 3rd et al. Quoting only the relevant definitions from that RFC for brevity: Used very generally as a sample name for absolutely anything, esp. programs and files (esp. scratch files). First on the standard list of metasyntactic variables used in syntax examples (bar, baz, qux, quux, corge, … Read more
While vs. Do While
It’s the query, or sometimes the query string. To pinch a useful diagram from the URI RFC: foo://example.com:8042/over/there?name=ferret#nose \_/ \______________/\_________/ \_________/ \__/ | | | | | scheme authority path query fragment
Convert to La*b* (aka just plain “Lab”, and you’ll also see reference to “CIELAB”). A good quick measaure of color difference is (L1-L2)^2 + (a1-a2)^2 + (b1-b2)^2 Color scientists have other more refined measures, which may not be worth the bother, depending on accuracy needed for what you’re doing. The a and b values represent … Read more
Implementation 1 returns the magnitude of the vector that would result from a regular 3D cross product of the input vectors, taking their Z values implicitly as 0 (i.e. treating the 2D space as a plane in the 3D space). The 3D cross product will be perpendicular to that plane, and thus have 0 X … Read more
With current logging frameworks, the question is moot Current logging frameworks like slf4j or log4j 2 don’t require guard statements in most cases. They use a parameterized log statement so that an event can be logged unconditionally, but message formatting only occurs if the event is enabled. Message construction is performed as needed by the … Read more
Check out the description of the Test-and-set machine instruction on Wikipedia, which alludes to how atomic operations are achieved at the machine level. I can imagine most language-level mutex implementations rely on machine-level support such as Test-and-set.