3.数据的整理.ppt

* * * * * * * * * * * * * * * * * * * * * * * * * * Shape Concerned with extent to which values are symmetrically distributed. Kurtosis The extent to which a distribution is peaked (flatter or taller). For example, a distribution could be more peaked than a normal distribution (still may be 慴ell-shaped). If values are negative, then distribution is less peaked than a normal distribution. Skew The extent to which a distribution is symmetric or has a tail. Values are 0 if normal distribution. If the values are negative, then negative or left-skewed. * * * * * 条行图指标轴长度不统一，造成视觉上误导 指标轴标签排序如果没有实际意义，则需要按数据大小排序。有意义的标签：时间、大小、级别、顺序等 单位为家数、个数，小数点没有意义需要去掉。 未显示全所有bar，调整刻度最大值。 视觉误差 美国的Fox News 数据差异极小，柱形图几乎成了整齐的栅栏，图表作用不明显。不如直接使用排序的数据表格。 频数分布的形状（常有U型、钟形与J形）类型