如何用r语言分组求均值

Question

如何用r语言分组求均值

Answer 1

执行语句写在方法里面sai :

public class dbbean {
public Connection getOrcaleConn(){

try{
DriverManager.registerDriver(new oracle.jdbc.driver.OracleDriver());
Connection con=DriverManager.getConnection("jdbc:oracle:thin:@133.81.9.101:1521:tongji","tongji","qazwsx");
}
catch(SQLException ce){
ce.printStackTrace();
}

return con;
}
}

Answer 2

vec = vector(length =1000)
for(i in 1:1000)
vec[i] = UR_FUNC()
mean(vec)