sinusoidal approximation meaning in English

正弦式近似法

As for nonlinear problem , the approximation schemes and the error analysis of pti are investigated , in order to avoid the computation of inverse matrix , the pti with dimensional expanding is proposed . the methods of constant , linear , sinusoidal approximation are proposed for the transformation of non - homogenous terms
通过增维技术，该算法将非齐次方程齐次化，从而避免了矩阵求逆，并给出非齐次项常数近似、线性近似和正弦余弦近似的处理方法。