标题: 如何计算截距？ [打印本页] 作者: shiyiming 时间: 2005-1-31 10:52 标题: 如何计算截距？ 有没有用sas做过回归分析的朋友，能帮我讲一下要用到的计算截距？
谢谢！作者: shiyiming 时间: 2005-2-18 20:25 标题: re For linear regression case:
x and y are two variables under consideration
if the least-squares line is y=a+bx (a is intercept and b is slope)
then b=r*sy/sx & [b:afa1f]a=ybar-b*xbar[/b:afa1f]
xbar and ybar are mean of x and y respectively
sx and sy are sample standard deviation
SAS/INSIGHT---(Analyze-Fit(Y X))---choose [b:afa1f]X [/b:afa1f]variable and [b:afa1f]Y[/b:afa1f] variable, then you can get a regression line and regression equation