Filter
Filter may refer to:
Chemistry, engineering and materials
In chemistry, engineering, or household usage, a device to separate mixtures. See:
- Filter (aquarium), critical components of both freshwater and marine aquaria
- Filter (chemistry), a device (usually a membrane or layer) that is designed to physically block certain objects or substances while letting others through
- Filter paper, a semi-permeable paper barrier placed perpendicular to a liquid or air flow. It is used to separate fine solids from liquids or air
- Air filter, a device composed of fibrous materials which removes solid particulates such as dust, pollen, mold, and bacteria from the air
- Oil filter, a filter to remove contaminants from engine oil, transmission oil, lubricating oil, or hydraulic oil
- Pneumatic filter, a device which removes contaminants from a compressed air stream
- Water filter, removes impurities from water by means of a fine physical barrier, a chemical process or a biological process. Filters cleanse water to various extents for irrigation, drinking water, aquariums, and swimming pools
Optics and photography
In optics and photography, a device to remove, or to enhance, certain ranges of wavelengths (colors) of light. See:
Turbulence modeling
In turbulence modeling, a procedure to dampen or remove the highest frequencies of the flow:
- Filter (large eddy simulation), in the context of large eddy simulation (LES) is a mathematical operation intended to remove a range of small scales from the solution to the Navier-Stokes equations
Signal processing
In signal processing, especially electronics, an algorithm or device for removing part(s) of a signal:
Computing
In computing:
- Filter (higher-order function), a higher-order function that processes a data structure (typically a list) in some order to produce a new data structure containing exactly those elements of the original data structure for which a given predicate returns the boolean value true
- A program to process a data stream:
- Filter (software), a computer program to process a data stream
- Filter (Unix), a program that gets most of its data from its standard input (the main input stream) and writes its main results to its standard output (the main output stream)
- Filter (video)
- Email filter
- Internet filter
- Wordfilter, a script typically used on Internet forums or chat rooms that automatically scans users' posts or comments as they are submitted and automatically changes or censors particular words or phrases
- BPF filter expression used in the qualification of network data
- DSL filter, a low-pass filter installed between analog devices and a telephone line
Philosophy
Other
- In mathematics, a certain kind of subset of a partially ordered set. See
- In psychology, a type of learning blockage. See
- Affective filter, an impediment to learning or acquisition caused by negative emotional ("affective") responses to one's environment. It is a hypothesis of second language acquisition theory, and a field of interest in educational psychology
- In transportation. See
- Filtering forward, a practice that cyclists use to pass slow or stopped congested traffic
Proper name
See also
- Filter coffee, a method for preparing coffee
- Filter feeder, an animal that strains food particles from water
- Philter, a magical potion
- Filtration, a mechanical or physical operation which is used for the separation of solids from fluids (liquids or gases) by interposing a medium through which only the fluid can pass
- Cigarette filter, a part of a cigarette intended to filter the smoke inhaled by a smoker