voltagesfrom

Voltagesfrom is a term used in circuit analysis and software tooling to denote the calculation or retrieval of node voltages produced by a specified set of excitations in a network. In academic contexts, it is not a standard mathematical operator; it is described as the result vector of nodal analysis given a network admittance matrix Y and a current source vector I. The voltagesfrom operation yields V, the vector of node voltages with respect to a chosen reference node, computed by solving Y V = I.

In practical terms, many circuit simulators expose a voltagesfrom-like interface. Users supply a circuit model, select the reference node, and the tool returns the node voltages. The same concept can be used to compute voltages across particular branches or between any pair of nodes by taking differences of the corresponding entries in V.

For linear, time-invariant networks, voltagesfrom reduces to a linear algebra problem that can be solved efficiently with sparse solvers. For circuits with nonlinear elements or time-varying sources, the voltagesfrom result becomes time-dependent and requires iterative or time-domain solution methods.

Origin and usage: voltagesfrom appears in documentation and tutorials as a descriptive label rather than a formal operator. It is often used interchangeably with nodal voltage computation, node voltage extraction, or voltage solution. See also nodal analysis, SPICE, impedance matrix, and Kirchhoff's circuit laws.