Piece-wise linear representation (PLR) separates a discrete-time continuous-valued signal into a few short data segments, each of which is represented by a straight line. One prerequisite parameter in the PLR is the number of data segments. This paper proposes a new method to determine the number of data segments. The method is based on a key observation on two balancing effects of the number of data segments on the confidence intervals of line approximations. The confidence intervals define parallelogram-shaped spaces, and an index is formulated as the weighted percentage of these spaces occupied by data points in data segments. The number of data segments is determined as the one achieving the maximum value of the formulated index. Numerical and industrial examples are provided to illustrate the effectiveness of the proposed method.

分段线性表示（PLR）将离散时间连续值信号分成几个短数据段，每个短数据段由一条直线表示。PLR中的一个必备参数是数据段的数量。本文提出了一种确定数据段数量的新方法。该方法基于对数据段数量对线近似的置信区间的两个平衡影响的关键观察。置信区间定义平行四边形形状的空间，并将索引公式化为数据段中数据点所占这些空间的加权百分比。数据段的数量确定为达到公式索引最大值的段。数值和工业算例说明了该方法的有效性。