Scalar field
= Scalar field
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A <scalar field> assigns one scalar to each point of a specified space, such as <Euclidean space> or <spacetime>. For example, $F(x,y)=x^2+2y^2$ is a <real-valued function> on a plane, and its change along a moving observation is given by the <derivative along a curve>. Under a change of coordinates, a scalar field's value at the same physical point is unchanged.