SAS中的虚拟变量
假设我们有一些数据集SAS中的虚拟变量,sas,Sas,假设我们有一些数据集people,其中有一个分类变量income,有4个级别(1,2,3,4)。我们将如何在SAS中编写此代码?是不是: data people; set people; if income=1 then income1=1; else if income=2 then income2=1 else if income =3 then income3=1; run; 换句话说,这将为四个级别创建三个虚拟变量。是这样吗?我已经修改了下面的代码。这将给出3个虚拟编码变量收入=4将
people
,其中有一个分类变量income
,有4个级别(1,2,3,4)。我们将如何在SAS中编写此代码?是不是:
data people;
set people;
if income=1 then income1=1;
else if income=2 then income2=1
else if income =3 then income3=1;
run;
换句话说,这将为四个级别创建三个虚拟变量。是这样吗?我已经修改了下面的代码。这将给出3个虚拟编码变量<代码>收入=4将是您的参考代码
data people_dummy;
set people;
if income=1 then income1=1 ; else income1=0;
if income=2 then income2=1 ; else income2=0;
if income=3 then income3=1 ; else income3=0;
run;
更灵活的方法是使用数组
data people;
set people;
array incomes income1-income4;
do _t = 1 to dim(incomes);
if income=_t then income[_t] = 1;
else if not missing(income) then income[_t]=0;
else income[_t]=.;
end;
run;
我会写一些更一般的东西
%macro cat(indata, variable);
proc sql noprint;
select distinct &variable. into :mvals separated by '|'
from &indata.;
%let mdim=&sqlobs;
quit;
data &indata.;
set &indata.;
%do _i=1 %to &mdim.;
%let _v = %scan(&mvals., &_i., |);
if &variable. = &_v. then &variable.&_v. = 1; else &variable.&_v = 0;
%end;
run;
%mend;
%cat(people, income);
你不必写“其他”。以下内容也将起作用:
income1_ind=(income1 eq 1);
income2_ind=(income2 eq 2);
代码:-
proc sql noprint;
select distinct 'income' || strip(put(income,8.)) into :income_var separated by ' '
from people;
quit;
data people(rename = (in = income));
set people(rename = (income = in));
length &income_var. 8;
array tmp_arr(*) income:;
do i = 1 to dim(tmp_arr);
if in eq i then tmp_arr(i) = 1;
else tmp_arr(i) = 0;
end;
drop i;
run;
工作:上述SAS代码是动态的,适用于任何级别的收入变量,因为它根据输入人员数据集中不同级别的数量自动创建变量数量
数据步骤将根据收入变量的值将相应变量设置为值1,将其他变量设置为0。您必须在else语句前的行后添加分号。