在Stata中,“missing values generated”是一个常见的提示,它表明在执行某些操作时,由于数据中的某些值不符合操作要求,这些值被自动标记为缺失值。下面是对这一问题的详细解答: 1. 什么是缺失值(missing values)? 缺失值是指在数据集中某些观测值缺失或未知的情况。在Stata中,缺失值用特定的符号表示,如.(系统缺漏...
(本小结主要参考翻译自How can I drop spells of missing values at the beginning and end of panel data?在此向文章作者表示感谢!) 首先,我们必须在面板的开始和结尾处分别找出缺失的数值 其次,按照时间变量的排序处理 (1)开头缺漏值删除 sum(mi(response)) //缺失值的运行记录 ...
就是有的变量的数据是缺失的，比如有个变量var1数据都是1和0，你生成一个变量，当var1=1的时候，var2等于5，因为var1中有的变量为0，这部分为0的观测值在var2里就是缺失值了
Why does Stata treat missing values in this way? It is not possible with two-valued logic (True–False) to have missing values propagate through logical statements. A Boolean expression must ultimately evaluate to either true or false. Consider the statement ...
Missing values may occur in blocks of two or more. Suppose you want to replace missings by the previous nonmissing value, whenever it occurred, so that given _n myvar 1 42 2 . 3 . 4 56 5 67 6 78 you want toreplacenot onlymyvar[2], but alsomyvar[3]with 42. ...
See[MI]Glossary for a definition of terms.To import data that already have imputations for the missing values(do not mi set the data)mi import import mi data mi export export mi data to non-Stata application Once data are mi set or mi import ed mi query query whether and how mi ...
用stata做门槛回归时出现matrix has missing values是什么原因呢?我的命令是xthenreg，做动态面板门槛回归...
Multiple imputation methods for handling missing values in longitudinal studies with sampling weights: Comparison of methods implemented in Statainverse probability weightinglongitudinal datamissing datamultiple imputationsampling weightMany analyses of longitudinal cohorts require incorporating sampling weights to ...
Missing values at the beginning of each panel were tallied in the order of the dataset as a whole, from first observation to last observation; in particular, this is the way cumulative sums are calculated usingsum(). More generally, Stata always works in this direction unless otherwise stipulat...
Why does the real function sometimes return missing values? TitleReal function returns missing values AuthorStata technical support real This includes blanks! real trim . gen nval = real(trim(sval))