Data Analysis, Free Course, STATA

How can you generate a variable in Stata

Published on June 5, 2023
360 Admin

Before starting this exercise, you should have the “Digital.dta” file. (Download link is given below)

Click here to download – “Digital.dta”

Importing the “Digital.dta” file.

set maxvar 10000
use "/Users/pankajchowdhury/Downloads/Digital.dta"

I have the file located at "/Users/pankajchowdhury/Downloads/Digital.dta". Feel free to modify the file path according to your needs.


Observations:	724115
Variables:	31
Variable name	Storage type	Display format	Value label	Variable label
v005	long	%12.0g	v005	women's individual sample weight (6 decimals)
v013	byte	%8.0g	V013	age in 5-year groups
v024	byte	%8.0g	V024	state
v025	byte	%8.0g	V025	type of place of residence
v130	byte	%8.0g	V130	religion
v133	byte	%8.0g	V133	education in single years
v151	byte	%8.0g	V151	sex of household head
v157	byte	%8.0g	V157	frequency of reading newspaper or magazine
v158	byte	%8.0g	V158	frequency of listening to radio
v159	byte	%8.0g	V159	frequency of watching television
v169a	byte	%8.0g	V169A	owns a mobile telephone
v190	byte	%8.0g	V190	wealth index combined
v217	byte	%8.0g	V217	knowledge of ovulatory cycle
v504	byte	%8.0g	V504	currently residing with husband/partner
v702	byte	%8.0g	V702	husband/partner's highest year of education (at level in v701)
v704	byte	%8.0g	V704	husband/partner's occupation
v715	byte	%8.0g	V715	husband/partner's total number of years of education
v730	byte	%8.0g	V730	husband/partner's age
v743f	byte	%8.0g	V743F	person who usually decides what to do with money husband earns
v746	byte	%8.0g	V746	respondent earns more than husband/partner
d005	long	%12.0g	d005	weight for domestic violence (6 decimals)
d102	byte	%8.0g	d012	number of control issues answered 'yes' (d101x = 1)
sweight	long	%12.0g	sweight	sample weight (6 decimals) (state level)
s116	byte	%8.0g	S116	belong to a scheduled caste, a scheduled tribe, other backward class
s303	int	%8.0g	S303	time period not living with husband
s311	byte	%8.0g	S311	type of relationship to current husband,prior to marriage
s931	byte	%8.0g	S931	do you have a bank or savings account that you yourself use
s932	byte	%8.0g	S932	do you have any mobile phone that you yourself use
s933	byte	%8.0g	S933	do you use your mobile phone for any financial transaction ?
s934	byte	%8.0g	S934	have you ever used the internet?
s1004p	byte	%8.0g	S1004P	source of information about aids: internet

Code 1.1:

codebook v730 
ta v730

Result : codebook v730– This command will check the variable type, variable label, Range, Unique values, value label and frequency distribution of a particular variable “v730”.


codebook	v730
v730 :	husband/partner's age
Type:	Numeric (byte)
Label:	V730, but 74 nonmissing values are not labeled
Range:	[15,95]	Units:	1
Unique values:	74	Missing :	647,033/724,115

Code 1.2:

ta v730

Result :

husband/partner's age	Freq.	Percent	Cum.
15	48	0.06	0.06
16	11	0.01	0.08
17	27	0.04	0.11
18	102	0.13	0.24
19	151	0.2	0.44
20	394	0.51	0.95
21	526	0.68	1.63
22	846	1.1	2.73
23	925	1.2	3.93
24	1,321	1.71	5.64
25	2,236	2.9	8.55
26	1,828	2.37	10.92
27	2,076	2.69	13.61
28	2,600	3.37	16.98
29	1,937	2.51	19.5
30	4,130	5.36	24.85
31	1,736	2.25	27.11
32	3,203	4.16	31.26
33	1,983	2.57	33.83
34	2,309	3	36.83
35	4,704	6.1	42.93
36	2,343	3.04	45.97
37	2,032	2.64	48.61
38	2,859	3.71	52.32
39	1,959	2.54	54.86
40	4,437	5.76	60.61
41	1,525	1.98	62.59
42	2,566	3.33	65.92
43	1,608	2.09	68.01
44	1,719	2.23	70.24
45	4,199	5.45	75.69
46	1,780	2.31	77.99
47	1,752	2.27	80.27
48	2,390	3.1	83.37
49	1,671	2.17	85.54
50	2,619	3.4	88.93
51	1,316	1.71	90.64
52	1,673	2.17	92.81
53	1,030	1.34	94.15
54	1,014	1.32	95.46
55	812	1.05	96.52
56	595	0.77	97.29
57	448	0.58	97.87
58	454	0.59	98.46
59	266	0.35	98.8
60	367	0.48	99.28
61	90	0.12	99.4
62	106	0.14	99.53
63	62	0.08	99.61
64	40	0.05	99.67
65	78	0.1	99.77
66	23	0.03	99.8
67	19	0.02	99.82
68	17	0.02	99.84
69	13	0.02	99.86
70	29	0.04	99.9
71	4	0.01	99.9
72	3	0	99.91
73	4	0.01	99.91
74	5	0.01	99.92
75	2	0	99.92
76	1	0	99.92
77	1	0	99.92
78	1	0	99.93
79	1	0	99.93
80	5	0.01	99.93
82	3	0	99.94
83	1	0	99.94
84	1	0	99.94
85	1	0	99.94
87	1	0	99.94
88	1	0	99.94
90	1	0	99.95
95	42	0.05	100
Total	77,082	100

Explanation : ta v730– this command will provide a frequency table comprising cumulative frequency and percentage distribution for variable v730.

Code 2:

gen five_year = 5
ta five_year

Explanation : gen five_year = 5 this command will create a variable that assigns the value of “5” to each observation.

Code 3:

gen int age_plus_five = v730 + five_year 
ta age_plus_five

Explanation : gen int age_plus_five = v730 + five_year– create a fresh variable ( variable type: int) by incrementing each value in the variable v730 by 5.

Result :

age_plus_five (v730+ Five year)	Freq.	Percent	Cum.
20	48	0.06	0.06
21	11	0.01	0.08
22	27	0.04	0.11
23	102	0.13	0.24
24	151	0.2	0.44
25	394	0.51	0.95
26	526	0.68	1.63
27	846	1.1	2.73
28	925	1.2	3.93
29	1,321	1.71	5.64
30	2,236	2.9	8.55
31	1,828	2.37	10.92
32	2,076	2.69	13.61
33	2,600	3.37	16.98
34	1,937	2.51	19.5
35	4,130	5.36	24.85
36	1,736	2.25	27.11
37	3,203	4.16	31.26
38	1,983	2.57	33.83
39	2,309	3	36.83
40	4,704	6.1	42.93
41	2,343	3.04	45.97
42	2,032	2.64	48.61
43	2,859	3.71	52.32
44	1,959	2.54	54.86
45	4,437	5.76	60.61
46	1,525	1.98	62.59
47	2,566	3.33	65.92
48	1,608	2.09	68.01
49	1,719	2.23	70.24
50	4,199	5.45	75.69
51	1,780	2.31	77.99
52	1,752	2.27	80.27
53	2,390	3.1	83.37
54	1,671	2.17	85.54
55	2,619	3.4	88.93
56	1,316	1.71	90.64
57	1,673	2.17	92.81
58	1,030	1.34	94.15
59	1,014	1.32	95.46
60	812	1.05	96.52
61	595	0.77	97.29
62	448	0.58	97.87
63	454	0.59	98.46
64	266	0.35	98.8
65	367	0.48	99.28
66	90	0.12	99.4
67	106	0.14	99.53
68	62	0.08	99.61
69	40	0.05	99.67
70	78	0.1	99.77
71	23	0.03	99.8
72	19	0.02	99.82
73	17	0.02	99.84
74	13	0.02	99.86
75	29	0.04	99.9
76	4	0.01	99.9
77	3	0	99.91
78	4	0.01	99.91
79	5	0.01	99.92
80	2	0	99.92
81	1	0	99.92
82	1	0	99.92
83	1	0	99.93
84	1	0	99.93
85	5	0.01	99.93
87	3	0	99.94
88	1	0	99.94
89	1	0	99.94
90	1	0	99.94
92	1	0	99.94
93	1	0	99.94
95	1	0	99.95
100	42	0.05	100
Total	77,082	100

Code 4:

gen int age_plus_five2 = v730 + five_year if v730 > 25 ta age_plus_five2

Explanation : gen int age_plus_five2 = v730 + five_year if v730 > 25 – When the age variable (v730) exceeds 30 years, executing this command will produce a new variable by incrementing each observation in v730 by five.

Results :

age_plus_five2	Freq.	Percent	Cum.
31	1,828	2.59	2.59
32	2,076	2.94	5.54
33	2,600	3.69	9.23
34	1,937	2.75	11.97
35	4,130	5.86	17.83
36	1,736	2.46	20.3
37	3,203	4.54	24.84
38	1,983	2.81	27.65
39	2,309	3.28	30.93
40	4,704	6.67	37.6
41	2,343	3.32	40.92
42	2,032	2.88	43.81
43	2,859	4.06	47.86
44	1,959	2.78	50.64
45	4,437	6.29	56.93
46	1,525	2.16	59.1
47	2,566	3.64	62.74
48	1,608	2.28	65.02
49	1,719	2.44	67.46
50	4,199	5.96	73.41
51	1,780	2.53	75.94
52	1,752	2.49	78.42
53	2,390	3.39	81.81
54	1,671	2.37	84.18
55	2,619	3.72	87.9
56	1,316	1.87	89.77
57	1,673	2.37	92.14
58	1,030	1.46	93.6
59	1,014	1.44	95.04
60	812	1.15	96.19
61	595	0.84	97.04
62	448	0.64	97.67
63	454	0.64	98.31
64	266	0.38	98.69
65	367	0.52	99.21
66	90	0.13	99.34
67	106	0.15	99.49
68	62	0.09	99.58
69	40	0.06	99.64
70	78	0.11	99.75
71	23	0.03	99.78
72	19	0.03	99.81
73	17	0.02	99.83
74	13	0.02	99.85
75	29	0.04	99.89
76	4	0.01	99.9
77	3	0	99.9
78	4	0.01	99.9
79	5	0.01	99.91
80	2	0	99.91
81	1	0	99.92
82	1	0	99.92
83	1	0	99.92
84	1	0	99.92
85	5	0.01	99.93
87	3	0	99.93
88	1	0	99.93
89	1	0	99.93
90	1	0	99.94
92	1	0	99.94
93	1	0	99.94
95	1	0	99.94
100	42	0.06	100
Total	70,495	100

Code 5:

gen age2 = v730^2
ta age2

Explanation : gen age2 = v730^2– By squaring the variable values, this command will create a new variable.

Results :

age2	Freq. Perc	ent	Cum.
225	48	0.06	0.06
256	11	0.01	0.08
289	27	0.04	0.11
324	102	0.13	0.24
361	151	0.2	0.44
400	394	0.51	0.95
441	526	0.68	1.63
484	846	1.1	2.73
529	925	1.2	3.93
576	1,321	1.71	5.64
625	2,236	2.9	8.55
676	1,828	2.37	10.92
729	2,076	2.69	13.61
784	2,600	3.37	16.98
841	1,937	2.51	19.5
900	4,130	5.36	24.85
961	1,736	2.25	27.11
1024	3,203	4.16	31.26
1089	1,983	2.57	33.83
1156	2,309	3	36.83
1225	4,704	6.1	42.93
1296	2,343	3.04	45.97
1369	2,032	2.64	48.61
1444	2,859	3.71	52.32
1521	1,959	2.54	54.86
1600	4,437	5.76	60.61
1681	1,525	1.98	62.59
1764	2,566	3.33	65.92
1849	1,608	2.09	68.01
1936	1,719	2.23	70.24
2025	4,199	5.45	75.69
2116	1,780	2.31	77.99
2209	1,752	2.27	80.27
2304	2,390	3.1	83.37
2401	1,671	2.17	85.54
2500	2,619	3.4	88.93
2601	1,316	1.71	90.64
2704	1,673	2.17	92.81
2809	1,030	1.34	94.15
2916	1,014	1.32	95.46
3025	812	1.05	96.52
3136	595	0.77	97.29
3249	448	0.58	97.87
3364	454	0.59	98.46
3481	266	0.35	98.8
3600	367	0.48	99.28
3721	90	0.12	99.4
3844	106	0.14	99.53
3969	62	0.08	99.61
4096	40	0.05	99.67
4225	78	0.1	99.77
4356	23	0.03	99.8
4489	19	0.02	99.82
4624	17	0.02	99.84
4761	13	0.02	99.86
4900	29	0.04	99.9
5041	4	0.01	99.9
5184	3	0	99.91
5329	4	0.01	99.91
5476	5	0.01	99.92
5625	2	0	99.92
5776	1	0	99.92
5929	1	0	99.92
6084	1	0	99.93
6241	1	0	99.93
6400	5	0.01	99.93
6724	3	0	99.94
6889	1	0	99.94
7056	1	0	99.94
7225	1	0	99.94
7569	1	0	99.94
7744	1	0	99.94
8100	1	0	99.95
9025	42	0.05	100
Total	77,082	100

Code 6:

gen age = sqrt(age2) ta age

Explanation :

gen age = sqrt(age2) – This command will create a new variable by substituting the variable values with their square root.

Results:

age	Freq.	Percent	Cum.
15	48	0.06	0.06
16	11	0.01	0.08
17	27	0.04	0.11
18	102	0.13	0.24
19	151	0.2	0.44
20	394	0.51	0.95
21	526	0.68	1.63
22	846	1.1	2.73
23	925	1.2	3.93
24	1,321	1.71	5.64
25	2,236	2.9	8.55
26	1,828	2.37	10.92
27	2,076	2.69	13.61
28	2,600	3.37	16.98
29	1,937	2.51	19.5
30	4,130	5.36	24.85
31	1,736	2.25	27.11
32	3,203	4.16	31.26
33	1,983	2.57	33.83
34	2,309	3	36.83
35	4,704	6.1	42.93
36	2,343	3.04	45.97
37	2,032	2.64	48.61
38	2,859	3.71	52.32
39	1,959	2.54	54.86
40	4,437	5.76	60.61
41	1,525	1.98	62.59
42	2,566	3.33	65.92
43	1,608	2.09	68.01
44	1,719	2.23	70.24
45	4,199	5.45	75.69
46	1,780	2.31	77.99
47	1,752	2.27	80.27
48	2,390	3.1	83.37
49	1,671	2.17	85.54
50	2,619	3.4	88.93
51	1,316	1.71	90.64
52	1,673	2.17	92.81
53	1,030	1.34	94.15
54	1,014	1.32	95.46
55	812	1.05	96.52
56	595	0.77	97.29
57	448	0.58	97.87
58	454	0.59	98.46
59	266	0.35	98.8
60	367	0.48	99.28
61	90	0.12	99.4
62	106	0.14	99.53
63	62	0.08	99.61
64	40	0.05	99.67
65	78	0.1	99.77
66	23	0.03	99.8
67	19	0.02	99.82
68	17	0.02	99.84
69	13	0.02	99.86
70	29	0.04	99.9
71	4	0.01	99.9
72	3	0	99.91
73	4	0.01	99.91
74	5	0.01	99.92
75	2	0	99.92
76	1	0	99.92
77	1	0	99.92
78	1	0	99.93
79	1	0	99.93
80	5	0.01	99.93
82	3	0	99.94
83	1	0	99.94
84	1	0	99.94
85	1	0	99.94
87	1	0	99.94
88	1	0	99.94
90	1	0	99.95
95	42	0.05	100
Total	77,082	100