半极坐标图形绘制函数halfPolar，用于生成角度范围在[0 pi]之间的极坐标图，并允许指定线条样式和刻度值。

简介：
The HALFPOLAR function operates within the radian angle range of [0 pi] to generate polar plots utilizing half-polar coordinates. Specifically, HALFPOLAR(phi, gain) produces a plot incorporating the angle phi and yields the corresponding half-polar coordinates within the same radian angle range of [0 pi]. The variables phi and gain can be vectors or matrices, ensuring they maintain identical dimensions. When phi is represented as a vector (1XN) and gain is also a vector (1XN), the matrix gain values are permissible. Conversely, if phi is a matrix (MXN), then the gain should correspond to another matrix of identical row numbers (MXN). Furthermore, HALFPOLAR(phi, gain, linestyle) utilizes a specified line style defined within the cell for plotting both phi and gain variables; for example, linestyle = {ko-,b--}. Additionally, HALFPOLAR(phi, gain, linestyle, xtickval) employs predetermined tick mark values xtickval as defined – such as xtickval = [15 25 45 75 105]. It’s crucial to note that HA