coming from a field. For example, scalars can come from a ring. But the theory is then less geometric and computations more technical and less algorithmic. Tensors are generalized within category theory by means of the concept of monoidal category, from the 1960s. See also Array data type, for tensor storage and manipulation Foundational Cartesian tensor Fibre bundle Glossary of tensor theory Multilinear projection One-form Tensor product of modules Applications Application of tensor theory in engineering Continuum mechanics Covariant derivative Curvature Diffusion tensor MRI Einstein field equations Fluid mechanics Gravity Multilinear subspace learning Riemannian geometry Structure tensor Tensor Contraction Engine Tensor decomposition Tensor derivative Tensor software Explanatory notes References Specific General Chapter six gives a "from scratch" introduction to covariant tensors. External links A discussion of the various approaches to teaching tensors, and recommendations of textbooks Concepts in physics