The plot origin is the lower-left corner of the specified plotted area and can be queried with the PlotOrigin property. Typically, the plot origin is set to (0, 0). However, a plot can be centered on the sheet of paper. The PlotCentered property returns if the plot is currently centered; if TRUE the plot is centered. Centering the plot alters the plot origin.
打印原点是指定打印区域的左下角点，可以用 PlotOrigin 属性获得。具有代表性的是，打印原点被设置在（0，0）点。然而，有可能将图形在纸张上居中打印出来。PlotCentered 属性返回当前的打印是否是居中的；如果为True，打印是居中的。居中打印将修改打印原点。
