In mathematics, an operator or transform is a function from one space of functions to another. Operators occur commonly in engineering, physics and mathematics. Many are integral operators and differential operators.
In the following L is an operator
which takes a function to another function . Here, and are some unspecified function spaces, such as Hardy space, Lp space, Sobolev space, or, more vaguely, the space of holomorphic functions.
Expression | Curve definition |
Variables | Description |
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Linear transformations | |||
Derivative of nth order | |||
Cartesian | Integral, area | ||
Composition operator | |||
Even component | |||
Odd component | |||
Difference operator | |||
Backward difference (Nabla operator) | |||
Indefinite sum operator (inverse operator of difference) | |||
Sturm–Liouville operator | |||
Non-linear transformations | |||
Inverse function | |||
Legendre transformation | |||
Left composition | |||
Indefinite product | |||
Geometric integral | |||
Bigeometric integral | |||
Logarithmic derivative | |||
Elasticity | |||
Schwarzian derivative | |||
Geometric derivative | |||
Bigeometric derivative | |||
Total variation | |||
Arithmetic mean | |||
Geometric mean | |||
Cartesian | Subtangent | ||
Parametric Cartesian |
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Polar | |||
Polar | Sector area | ||
Cartesian | Arc length | ||
Parametric Cartesian |
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Polar | |||
Cartesian | Affine arc length | ||
Parametric Cartesian |
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Parametric Cartesian |
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Cartesian | Curvature | ||
Parametric Cartesian |
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Polar | |||
Parametric Cartesian |
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Cartesian | Affine curvature | ||
Parametric Cartesian |
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Parametric Cartesian |
Torsion of curves | ||
Parametric Cartesian |
Dual curve (tangent coordinates) |
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Parametric Cartesian |
Parallel curve | ||
Parametric Cartesian |
Evolute | ||
Intrinsic | |||
Parametric Cartesian |
Involute | ||
Parametric Cartesian |
Pedal curve with pedal point (0;0) | ||
Parametric Cartesian |
Negative pedal curve with pedal point (0;0) | ||
Intrinsic | Intrinsic to Cartesian transformation |
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Metric functionals | |||
Norm | |||
Inner product | |||
Fubini-Study metric (inner angle) |
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Distribution functionals | |||
Convolution | |||
Differential entropy | |||
Expected value | |||
Variance |