Shulou(Shulou.com)06/03 Report--

27 commonly used Stata commands

[1] directly import data in csv format

Insheet using name.csv, clear

[2] modify variable length

Format var 20.2g

[3] Delete duplicate values

Sort var1 var2

Duplicatesdrop var1 var2, force

[4] data merge

Use data1, clear

Merge m:m var1var2 using data2

Drop if _ merge==2

Drop if _ merge==1

Drop _ merge

[5] generate the lag term of the first period

Tsset stkcd accper

Gen newvarname=L.varname

[6] convert text to numeric variables

GenBigN=0

ReplaceBigN=1 if strmatch (dadtunit, PricewaterhouseCoopers *)

[7] Delete records with missing values

Egen mis=rowmiss (_ all)

Drop if mis

Drop mis

[8] Industry division

Clonevarsic2=ind

Order stkcd accper sic2

Replace sic2=substr (sic2,1,1) if substr (sic2,1,1)! = "C"

Replace sic2=substr (sic2,1,2) if substr (sic2,1,1) = = "C"

Tabulate sic2 accper

[9] date is reserved only for year

Drop if substr (reptdt, 6. 2)! = "12"

Replace reptdt=substr (reptdt,1,4)

Gen accper=real (reptdt)

[10] data disaggregation

Split date, parse (-) destring ignor ("-")

[11] calculate the number of days between two dates

G td=date (trading_date, "YMD")

G ed=date (eventdate, "YMD")

Form td ed td

G d=ed-td

[12] generate industry and year dumb variables

Tab year, gen (year)

Tab industry, gen (industry)

[13] Winsorize processing of the data

Findit winsor2

Winsor2 varname, replace cut (1 99)

[14] descriptive statistics

Tabstat var1var2, stat (n min mean median p25 p75 max sd), if groupvar==0 or 1

Logout, save (name) word replace: tabstat var, stat (n min mean p50 max sd) col (stat) f (% 9.2g)

[15] contingency table of two variables

Tabulate var1 var2, row chi2 taub gamma

[16] mean T test between two samples

Ttest var, by (groupvar)

[17] median Z test of two samples

Ranksum var, by (groupvar)

[18] Pearson/Spearman coefficient

Spearmanx

N mata

X=st_data (., "x")

C=correlation (x)

N=rows (c)

B=strofreal (lowertriangle (c) + uppertriangle (st_matrix ("r (Rho)")), "9.3f")

P=st_matrix ("r (P)")

For (iTunes 2; I

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