6. 6
4. NhËp v l−u d÷ liÖu (Use, input and and save)
Më tÖp sè liÖu ®ang cã:
TÖp sè liÖu Stata cã thÓ ®−îc më b»ng lùa chän Open trªn thùc ®¬n File; hoÆc nót Open (use) trªn
thanh c«ng cô tool bar.
NÕu file sè liÖu cã dung l−îng lín th× chóng ta ph¶i thiÕt lËp bé nhí cÇn dïng cho Stata b»ng lÖnh:
set memory #[k|m]
VÝ dô:
set mem 32m
set mem 32000k
NhËp sè liÖu
Cã mét sè c¸ch ®Ó nhËp sè liÖu tõ b n phÝm v o bé nhí cña Stata.
- Sö dông cöa sæ Stata editor ®Ó nhËp sè liÖu. HoÆc tõ cöa sæ command, gâ lÖnh edit. Sau ®ã
nhËp sè liÖu theo kiÓu biÓu b¶ng trong cöa sæ n y.
7. 7
Stata cho phÐp nhËp sè liÖu tõ c¸c file c¬ së d÷ liÖu kh¸c. Tr−íc hÕt c¸c file sè liÖu n y cÇn ®−îc l−u
tr÷ d−íi d¹ng text (cã thÓ b»ng ch−¬ng tr×nh Excel), c¸c quan s¸t ®−îc c¸c nhau 1 dßng v c¸c gi¸ trÞ
c¸ch nhau 1 dÉu phÈy (commas) hoÆc dÊu c¸ch (tab). Sau ®ã dïng lÖnh copy v paste ®Ó nhËp sè liÖu
n y v o Stata.
L−u tr÷ sè liÖu
ViÖc l−u tr÷ sè liÖu cã thÓ thùc hiÖn b»ng c¸c tïy chän Save v Save as ë trong thanh thùc ®¬n (menu
bar); hoÆc nót Save trªn thanh c«ng cô (tool bar).
Chó ý: Xem thªm lÖnh infile v outfile
56. 56
graph [danh s¸ch biÕn] [quyÒn sè] [®iÒu kiÖn] [ph¹m vi] [, lo¹i_®å_thÞ tuú_chän_riªng
tuú_chän_chung]
Trong ®ã:
lo¹i_®å_thÞ (graph_type) ChØ ra lo¹i ®å thÞ cÇn vÏ
tuú_chän_riªng (specific_options) C¸c tuú chän liªn quan ®Õn tõng lo¹i ®å thÞ
tuú_chän_chung (common_options) C¸c tuú chän cã thÓ sö dông chung cho c¸c lo¹i ®å thÞ nh− tuú
chän vÒ ®¸nh nh n trªn c¸c trôc cña ®å thÞ
Stata cho phÐp vÏ 8 lo¹i ®å thÞ nh− sau (graph_type):
(1) §å thÞ 2 chiÒu (two-way scatterplots)
. graph rlpcex1 age
comp.M&Regpriceadj.pctotexp
Age of household head
16 95
357.318
45801.7
(2) Ma trËn ®å thÞ 2 chiÒu (two-way scatterplot matrices)
. gr rlpcex1 age educyr98 hhsize, matrix
57. 57
comp.M&Reg price
adj.pc tot exp
16
95
357.318 45801.7
1
19
16 95
Age of household
head
schooling year
of HH.head
0 22
357.318
45801.7
1 19
0
22
Household size
(3) §å thÞ tÇn suÊt (histograms)
. gr rlpcex1, bin(50) normal
Fraction
comp.M&Reg price adj.pc tot exp
357.318 45801.7
0
.329888
(4) §å thÞ r¶i mét chiÒu (one-way scatterplots)
. gr rlpcex1, oneway
58. 58
comp.M&Reg price adj.pc tot exp357.318 45801.71
(5) §å thÞ h×nh hép (box-and-whisker plots)
357.318
45801.7
comp.M&Reg price adj.pc tot exp
(6) §å thÞ cét (bar chart)
. sort reg7
. gr poor, bar means by(reg7)
59. 59
0
.498254
poor
1 2 3 4 5 6 7
(7) §å thÞ h×nh trßn (pie charts)
. for num 1/7: gen poorX=poor if reg7==X
-> gen poor1=poor if reg7==1
(5140 missing values generated)
-> gen poor2=poor if reg7==2
(4824 missing values generated)
-> gen poor3=poor if reg7==3
(5291 missing values generated)
-> gen poor4=poor if reg7==4
(5245 missing values generated)
-> gen poor5=poor if reg7==5
(5631 missing values generated)
-> gen poor6=poor if reg7==6
(4976 missing values generated)
-> gen poor7=poor if reg7==7
(4887 missing values generated)
. graph poor1-poor7, pie
60. 60
24% poor1
16% poor2
16% poor3
12% poor4
10% poor5
4% poor6
18% poor7
(8) §å thÞ h×nh sao (star charts)
chart_type l star
Price
Mileage (mpg)
Repair Record 1978
Headroom (in.)
Trunk space (cu. ft.)
Weight (lbs.)
Length (in.)
Turn Circle (ft.)
Displacement (cu. in.)
Audi 5000 Audi Fox BMW 320i Datsun 200 Datsun 210
Datsun 510 Datsun 810 Fiat Strada Honda Accord Honda Civic
Mazda GLC Renault Subaru Toyota Celica Toyota Corolla
Toyota Corona VW Dasher VW Diesel VW Rabbit VW Scirocco
Volvo 260
C¸c lùa chän chung (common_options)
* T¹o tÖp sè liÖu
. tabulate hhsize, sum (rlpcex1)
| Summary of comp.M&Reg price adj.pc
Household | tot exp
size | Mean Std. Dev. Freq.
------------+------------------------------------
1 | 4696.0254 4619.5012 214
62. 62
ahhsize
meanexp meanedu
1 19
1.57978
8.25783
* Lùa chän vÒ tiªu ®Ò:
title("chuçi ký tù") t1title("chuçi ký tù") t2title("chuçi ký tù") b1title("chuçi ký tù")
b2title("chuçi ký tù") l1title("chuçi ký tù") l2title("chuçi ký tù") r1title("chuçi ký tù")
r2title("chuçi ký tù")
LÖnh n y ghi c¸c tiªu ®Ò trªn phÝa trªn (top), phÝa d−íi (bottom), bªn tr¸i (left) v bªn ph¶i (right) ®å
thÞ.
VÝ dô:
gr meanexp meanedu ahhsize, title (Do thi chi tieu va hoc van chu ho) l1title(Chi tieu binh quan (tr
dong)) l2title(So nam hoc cua chu ho) b2title (Quy mo ho gia dinh)
Chitieubinhquan(trdong)
Sonamhoccuachuho
Do thi chi tieu va hoc van chu ho
Quy mo ho gia dinh
Chi tieu binh quan So nam hoc
1 19
1.57978
8.25783
63. 63
* HiÓn thÞ gi¸ trÞ trôc ®å thÞ
xlabel[(gi¸ trÞ sè)] ylabel[(gi¸ trÞ sè)] rlabel[(gi¸ trÞ sè)] tlabel[(gi¸ trÞ sè)]
VÝ dô:
gr meanexp meanedu ahhsize, title (Do thi chi tieu va hoc van chu ho) l1title(Chi tieu binh quan (tr
dong)) l2title(So nam hoc cua chu ho) b2title (Quy mo ho gia dinh) xlabel ylabel
Chitieubinhquan(trdong)
Sonamhoccuachuho
Do thi chi tieu va hoc van chu ho
Quy mo ho gia dinh
Chi tieu binh quan So nam hoc
0 5 10 15 20
2
4
6
8
Chó ý: C¸c lùa chän kh¸c cã thÓ xem ë phÇn help b»ng lÖnh: help graxes
C¸c tuú chän vÒ ®−êng nèi
xline[(gi¸ trÞ sè)] yline[(gi¸ trÞ sè)] rline[(gi¸ trÞ sè)] tline[(gi¸ trÞ sè)]
connect(c[[p]] ... c[[p]])
VÝ dô:
. gr meanexp meanedu ahhsize, title (Do thi chi tieu va hoc van chu ho) l1title(Chi tieu binh quan (tr
dong)) l2title(So nam hoc cua chu ho) b2title (Quy mo ho gia dinh) xlabel ylabel xline (5 10 to 20)
yline(2 4 to 8) connect(ll)
64. 64
Chitieubinhquan(trdong)
Sonamhoccuachuho
Do thi chi tieu va hoc van chu ho
Quy mo ho gia dinh
Chi tieu binh quan So nam hoc
0 5 10 15 20
2
4
6
8
2. Mét sè lo¹i ®å thÞ th−êng dïng
2.1. §å thÞ 2 chiÒu
Có ph¸p:
graph [danh s¸ch biÕn] [quyÒn sè] [®iÒu kiÖn] [ph¹m vi], twoway [tuú_chän_chung rescale]
Tuú chän rescale cho phÐp hiÖn thÞ hai trôc tung víi gi¸ trÞ kh¸c nhau
. gen meanexp1=meanexp*1000
. label var meanexp1 "Chi tieu binh quan"
. gr meanexp1 meanedu ahhsize, title (Do thi chi tieu va hoc van chu ho) l1title(Chi tieu binh quan
(nghin dong)) b2title (Quy mo ho gia dinh) xlabel ylabel rlabel(2 4 to 8) connect(ll) rescale
66. 66
Fraction
comp.M&Reg price adj.pc tot exp
357.318 45801.7
0
.56026
. gr rlpcex1, hist bin(50) normal freq
Frequency
comp.M&Reg price adj.pc tot exp
357.318 45801.7
0
1979
. gr rlpcex1, hist bin(50) normal freq by(reg7)
67. 67
Frequency
Histograms by Code by 7 regions
comp.M&Reg price adj.pc tot exp
region1
0
415
region2 region3
region4
0
415
region5
357.318 45801.7
region6
357.318 45801.7
region7
357.318 45801.7
0
415
2.3. §å thÞ h×nh cét
Có ph¸p:
graph [danh s¸ch biÕn] [quyÒn sè] [®iÒu kiÖn] [ph¹m vi], bar [tuú_chän_chung [no]alt means
stack]
VÝ dô:
§å thÞ gi¸ trÞ trung b×nh häc vÊn cña chñ hé v quy m« hé gia ®×nh theo 7 vïng
. gr educyr98 hhsize, bar means by(reg7)
0
8.64426
schooling year of HH.head Household size
1 2 3 4 5 6 7
. label define region 1 "region1" 2 "region2" 3 "region3" 4 "region4" 5 "region5" 6 "region6" 7
"region7"
68. 68
. label values reg7 region
. tab reg7
Code by 7 |
regions | Freq. Percent Cum.
------------+-----------------------------------
region1 | 859 14.32 14.32
region2 | 1175 19.59 33.91
region3 | 708 11.80 45.71
region4 | 754 12.57 58.28
region5 | 368 6.13 64.41
region6 | 1023 17.05 81.46
region7 | 1112 18.54 100.00
------------+-----------------------------------
Total | 5999 100.00
. gr educyr98 hhsize, bar means by(reg7) ylabel( 2 4 to 10) alt
2
4
6
8
10
schooling year of HH.head Household size
region1
region2
region3
region4
region5
region6
region7
Lùa chän stack
. gen persons=1
. gr persons urban98, bar ylabel by(reg7) stack alt
69. 69
0
500
1000
1500
persons 1:urban 98; 0:rural 98
region1
region2
region3
region4
region5
region6
region7
VÝ dô:
H y vÔ ®å thÞ sau:
0
200
400
600
foodpoor poor
region1
region2
region3
region4
region5
region6
region7
2.4. §å thÞ h×nh trßn
Có ph¸p:
graph [danh s¸ch biÕn] [quyÒn sè] [®iÒu kiÖn] [ph¹m vi], pie [tuú_chän_chung]
LÖnh n y vÏ ®å thÞ h×nh trßn Mèi biÕn sÏ chiÕm 1 phÇn cña h×nh trßn v tû lÖ cña phÇn n y do tæng gi¸
trÞ cña c¸c quan s¸t cu¶ biÕn ®ã quyÕt ®Þnh.
VÝ dô:
VÏ ®å thÞ tû lÖ phÇn tr¨m sè ng−êi nghÌo cña mçi vïng trªn tæng sè ng−êi nghÌo cña c¶ n−íc.
. gr poor1-poor7, pie
70. 70
24% poor1
16% poor2
16% poor3
12% poor4
10% poor5
4% poor6
18% poor7
. gen nonfpood=poor- foodpoor
. label var nonfpood "poor but still above food poverty line"
. gen nonpoor=( rlpcex1>=1790)
. gr foodpoor nonfpood nonpoor, pie
. set textsize 90
12% foodpoor
18% poor but still above food povert
70% nonpoor
. set textsize 100
. gr foodpoor nonfpood nonpoor, pie by(reg7) total
71. 71
12% foodpoor
18% poor but still above food povert
70% nonpoor
region1 region2 region3
region4 region5 region6
region7 Total
3. L−u tr÷ v hiÓn thÞ ®å thÞ (Saving and graph using)
§Ó l−u tr÷ ®å thÞ th× t¹i cöa sæ graph, v o thùc ®¬n File, chän Save graph, sau ®ã lùa chän ®−êng dÉn
v tªn file cho ®å thÞ, phÇn më réng ngÇm ®Þnh l gph.
§å thÞ còng cã thÓ ®−îc l−u tr÷ b»ng tuú chän saving(tªn tÖp [,replace]) viÕt sau lÖnh graph
VÝ dô:
. gr educyr98 hhsize, bar means by(reg7) ylabel( 2 4 to 10) alt saving ("c: do thi 1")
. gr persons urban98, bar ylabel by(reg7) stack alt saving("c:do thi 2")
§Ó kh«ng hiÓn thÞ ®å thÞ th× cã thÓ dïng lÖnh t¾t chÕ ®é hiÓn thÞ ®å thÞ b»ng lÖnh
set graphics { on | off }
. set graphics off
. gr poor1-poor7, pie saving ("c:do thi 3", replace)
(note: file c:do thi 3.gph not found)
Stata cho phÐp hiÓn thÞ c¸c ®å thÞ ® l−u tr÷ b»ng lÖnh:
graph using <tÖp tÖp ®å thÞ 1> [tÖp tÖp ®å thÞ 2 ...] [, margin(#)]
margin(#) chØ ra kho¶ng c¸ch lÒ bao quanh ®å thÞ theo gi¸ trÞ phÇn tr¨m cña diÖn tÝch ®å thÞ. Gi¸ trÞ
ngÇm ®Þnh l 0.
VÝ dô:
. set graphics on
72. 72
. graph using "c:do thi 1" "c:do thi 2" "c:do thi 3", margin(10) title("Mot so dac diem cua ho gia
dinh")
Mot so dac diem cua ho gia dinh
12% foodpoor
18% poor but still above food povert
70% nonpoor
region1 region2 region3
region4 region5 region6
region7 Total
0
500
1000
1500
persons 1:urban 98; 0:rural 98
region1
region2
region3
region4
region5
region6
region7
24% poor1
16% poor2
16% poor3
12% poor4
10% poor5
4% poor6
18% poor7
Chó ý:
Chóng ta co thÓ kÕt hîp lÖnh saving víi using ®Ó l−u tr÷ ra ®å thÞ míi. VÝ dô:
. graph using "c:do thi 1" "c:do thi 2" "c:do thi 3", margin(10) title("Mot so dac die m cua ho gia
dinh") saving("c:do thi tong hop")
. graph using "c:do thi tong hop"