Residual (numerical analysis)

 

 

In many cases, the smallness of the residual means that the approximation is close to the solution, i.e.,

 

残差：结果的差值

误差：近似解与解的差值

https://en.wikipedia.org/wiki/Residual_(numerical_analysis)

Loosely speaking, a residual is the error in a result. To be precise, suppose we want to find x such that

 

Given an approximation x₀ of x, the residual is

 

whereas the error is

If the exact value of x is not known, the residual can be computed, whereas the error cannot.