befehle

Question 1

zusammenfassen

Answer 1

summarize

Answer 2

outreg2

Question 3

age detailiert zusammenfassen wenn 1999 geboren

Answer 3

summarize age if year==1999, detail

Question 4

comments in do files

Answer 4

comment with one line *
comments of more than one line /* text */
comments within one line // text
line-join indicator: /// at the end of the command, if command is longer than one line

Question 5

find out working directory

Answer 5

pwd

Question 6

center of the data

Answer 6

what would be a typical observation

mean
-> sum of observations / number of observations

Question 7

variability of data

Answer 7

how is the data spread around the centre

standard deviation

Question 8

value lables, numerical value in same summary

Answer 8

fre

ssc install fre, replace

Question 9

value lables shown in summary

Answer 9

tabulate

Question 10

show distribution of var1 in a graphic

Answer 10

-> histogramm
hist var1, frequency

Question 11

select if the variable has the value 0

Answer 11

if x==0

Question 12

select if the variable does not have the value 0

Answer 12

if x != 0

Question 13

select if the variable has a value less than 0

Answer 13

if x< 0

Question 14

select if the variable has a value greater than or equal to 0 and less than 1

Answer 14

if x >= 0 & x<1

Question 15

select if the variable has a balue greater than or queal to 0 or a value less than 1

Answer 15

if x >= 0|x<1

Question 16

select if the variable has a missing value

Answer 16

if x ==.

if mi(x)

Question 17

select if the variable has a valid value

Answer 17

if x < .

if !mi(x)

Question 18

boxplot

Answer 18

graph box

zwei boxplots zb 1x für f und 1x m
graph box var1, by (sex)

Question 19

value labels should change

Answer 19

recode

Question 20

scatterplots

Answer 20

well suited for two metric variables
(dont work well with few values)

command:
scatter
twoway scatter var1 (y) var2(x)
twoway scatter var1 var2, by (sex)

-can be used to check whether a relationship is non-linear