-------------------------------------------------------------------------------------------- name: log: C:\Users\tgindlin\Desktop\class_example.log log type: text opened on: 15 Sep 2016, 17:39:55 . input data1 data1 1. clear 'clear' cannot be read as a number 1. end . input family person salary hours tall family person salary hours tall 1. 1 1 10 5 4 2. 1 2 20 5 5 3. 2 1 30 6 5.5 4. 2 2 30 7 5 5. end . list +-----------------------------------------+ | family person salary hours tall | |-----------------------------------------| 1. | 1 1 10 5 4 | 2. | 1 2 20 5 5 | 3. | 2 1 30 6 5.5 | 4. | 2 2 30 7 5 | +-----------------------------------------+ . save data1 file data1.dta saved . clear . use "C:\Users\tgindlin\Desktop\data1.dta", clear . l +-----------------------------------------+ | family person salary hours tall | |-----------------------------------------| 1. | 1 1 10 5 4 | 2. | 1 2 20 5 5 | 3. | 2 1 30 6 5.5 | 4. | 2 2 30 7 5 | +-----------------------------------------+ . clear . use "C:\Users\tgindlin\Desktop\data1.dta", clear . use data1 . use data1 . save data2 file data2.dta saved . clear . use data1 . use data2 . clear . use data1 . l +-----------------------------------------+ | family person salary hours tall | |-----------------------------------------| 1. | 1 1 10 5 4 | 2. | 1 2 20 5 5 | 3. | 2 1 30 6 5.5 | 4. | 2 2 30 7 5 | +-----------------------------------------+ . describe Contains data from data1.dta obs: 4 vars: 5 15 Sep 2016 17:44 size: 80 -------------------------------------------------------------------------------------------- storage display value variable name type format label variable label -------------------------------------------------------------------------------------------- family float %9.0g person float %9.0g salary float %9.0g hours float %9.0g tall float %9.0g -------------------------------------------------------------------------------------------- Sorted by: . summarize Variable | Obs Mean Std. Dev. Min Max -------------+--------------------------------------------------------- family | 4 1.5 .5773503 1 2 person | 4 1.5 .5773503 1 2 salary | 4 22.5 9.574271 10 30 hours | 4 5.75 .9574271 5 7 tall | 4 4.875 .6291529 4 5.5 . sum family Variable | Obs Mean Std. Dev. Min Max -------------+--------------------------------------------------------- family | 4 1.5 .5773503 1 2 . sum family person Variable | Obs Mean Std. Dev. Min Max -------------+--------------------------------------------------------- family | 4 1.5 .5773503 1 2 person | 4 1.5 .5773503 1 2 . sum salary, detail salary ------------------------------------------------------------- Percentiles Smallest 1% 10 10 5% 10 20 10% 10 30 Obs 4 25% 15 30 Sum of Wgt. 4 50% 25 Mean 22.5 Largest Std. Dev. 9.574271 75% 30 10 90% 30 20 Variance 91.66667 95% 30 30 Skewness -.4933822 99% 30 30 Kurtosis 1.628099 . tabulate salary salary | Freq. Percent Cum. ------------+----------------------------------- 10 | 1 25.00 25.00 20 | 1 25.00 50.00 30 | 2 50.00 100.00 ------------+----------------------------------- Total | 4 100.00 . tab salary tall | tall salary | 4 5 5.5 | Total -----------+---------------------------------+---------- 10 | 1 0 0 | 1 20 | 0 1 0 | 1 30 | 0 1 1 | 2 -----------+---------------------------------+---------- Total | 1 2 1 | 4 . corr salary tall (obs=4) | salary tall -------------+------------------ salary | 1.0000 tall | 0.8992 1.0000 . corr salary tall hours (obs=4) | salary tall hours -------------+--------------------------- salary | 1.0000 tall | 0.8992 1.0000 hours | 0.8182 0.4842 1.0000 . summarize salary Variable | Obs Mean Std. Dev. Min Max -------------+--------------------------------------------------------- salary | 4 22.5 9.574271 10 30 . tabulate salary hours | hours salary | 5 6 7 | Total -----------+---------------------------------+---------- 10 | 1 0 0 | 1 20 | 1 0 0 | 1 30 | 0 1 1 | 2 -----------+---------------------------------+---------- Total | 2 1 1 | 4 . l +-----------------------------------------+ | family person salary hours tall | |-----------------------------------------| 1. | 1 1 10 5 4 | 2. | 1 2 20 5 5 | 3. | 2 1 30 6 5.5 | 4. | 2 2 30 7 5 | +-----------------------------------------+ . drop tall . l +----------------------------------+ | family person salary hours | |----------------------------------| 1. | 1 1 10 5 | 2. | 1 2 20 5 | 3. | 2 1 30 6 | 4. | 2 2 30 7 | +----------------------------------+ . drop if salary=10 =exp not allowed r(101); . drop if salary==10 (1 observation deleted) . l +----------------------------------+ | family person salary hours | |----------------------------------| 1. | 1 2 20 5 | 2. | 2 1 30 6 | 3. | 2 2 30 7 | +----------------------------------+ . drop if salary<=20 (1 observation deleted) . l +----------------------------------+ | family person salary hours | |----------------------------------| 1. | 2 1 30 6 | 2. | 2 2 30 7 | +----------------------------------+ . l +----------------------------------+ | family person salary hours | |----------------------------------| 1. | 2 1 30 6 | 2. | 2 2 30 7 | +----------------------------------+ . save data2 file data2.dta already exists r(602); . save data2, replace file data2.dta saved . clear . use data2 . l +----------------------------------+ | family person salary hours | |----------------------------------| 1. | 2 1 30 6 | 2. | 2 2 30 7 | +----------------------------------+ . use data1 . l +-----------------------------------------+ | family person salary hours tall | |-----------------------------------------| 1. | 1 1 10 5 4 | 2. | 1 2 20 5 5 | 3. | 2 1 30 6 5.5 | 4. | 2 2 30 7 5 | +-----------------------------------------+ . histogram salary, frequency (bin=2, start=10, width=10) . twoway (scatter salary tall) . twoway (line salary tall) . twoway (line salary tall, sort) . twoway (lfit salary tall) . twoway (lfit salary tall)(scatter salary tall) . generate short = =1 if tall<5 =1 invalid name r(198); . generate short=1 if tall<5 (3 missing values generated) . l +-------------------------------------------------+ | family person salary hours tall short | |-------------------------------------------------| 1. | 1 1 10 5 4 1 | 2. | 1 2 20 5 5 . | 3. | 2 1 30 6 5.5 . | 4. | 2 2 30 7 5 . | +-------------------------------------------------+ . replace short=0 if tall>4 (3 real changes made) . l +-------------------------------------------------+ | family person salary hours tall short | |-------------------------------------------------| 1. | 1 1 10 5 4 1 | 2. | 1 2 20 5 5 0 | 3. | 2 1 30 6 5.5 0 | 4. | 2 2 30 7 5 0 | +-------------------------------------------------+ . gen wage=salary/hours . l +------------------------------------------------------------+ | family person salary hours tall short wage | |------------------------------------------------------------| 1. | 1 1 10 5 4 1 2 | 2. | 1 2 20 5 5 0 4 | 3. | 2 1 30 6 5.5 0 5 | 4. | 2 2 30 7 5 0 4.285714 | +------------------------------------------------------------+ . gen sumwage=sum(wage) . l +-----------------------------------------------------------------------+ | family person salary hours tall short wage sumwage | |-----------------------------------------------------------------------| 1. | 1 1 10 5 4 1 2 2 | 2. | 1 2 20 5 5 0 4 6 | 3. | 2 1 30 6 5.5 0 5 11 | 4. | 2 2 30 7 5 0 4.285714 15.28571 | +-----------------------------------------------------------------------+ . egen sumwage2=sum(wage) . l +----------------------------------------------------------------------------------+ | family person salary hours tall short wage sumwage sumwage2 | |----------------------------------------------------------------------------------| 1. | 1 1 10 5 4 1 2 2 15.28571 | 2. | 1 2 20 5 5 0 4 6 15.28571 | 3. | 2 1 30 6 5.5 0 5 11 15.28571 | 4. | 2 2 30 7 5 0 4.285714 15.28571 15.28571 | +----------------------------------------------------------------------------------+ . sort family . l +----------------------------------------------------------------------------------+ | family person salary hours tall short wage sumwage sumwage2 | |----------------------------------------------------------------------------------| 1. | 1 1 10 5 4 1 2 2 15.28571 | 2. | 1 2 20 5 5 0 4 6 15.28571 | 3. | 2 1 30 6 5.5 0 5 11 15.28571 | 4. | 2 2 30 7 5 0 4.285714 15.28571 15.28571 | +----------------------------------------------------------------------------------+ . sort person . l +----------------------------------------------------------------------------------+ | family person salary hours tall short wage sumwage sumwage2 | |----------------------------------------------------------------------------------| 1. | 1 1 10 5 4 1 2 2 15.28571 | 2. | 2 1 30 6 5.5 0 5 11 15.28571 | 3. | 1 2 20 5 5 0 4 6 15.28571 | 4. | 2 2 30 7 5 0 4.285714 15.28571 15.28571 | +----------------------------------------------------------------------------------+ . sort family . by family: summarize salary -------------------------------------------------------------------------------------------- -> family = 1 Variable | Obs Mean Std. Dev. Min Max -------------+--------------------------------------------------------- salary | 2 15 7.071068 10 20 -------------------------------------------------------------------------------------------- -> family = 2 Variable | Obs Mean Std. Dev. Min Max -------------+--------------------------------------------------------- salary | 2 30 0 30 30 . by family, sort : summarize salary -------------------------------------------------------------------------------------------- -> family = 1 Variable | Obs Mean Std. Dev. Min Max -------------+--------------------------------------------------------- salary | 2 15 7.071068 10 20 -------------------------------------------------------------------------------------------- -> family = 2 Variable | Obs Mean Std. Dev. Min Max -------------+--------------------------------------------------------- salary | 2 30 0 30 30 . egen meansal=mean(salary), by(family) . l +----------------------------------------------------------------------------------+ 1. | family | person | salary | hours | tall | short | wage | sumwage | sumwage2 | | 1 | 2 | 20 | 5 | 5 | 0 | 4 | 6 | 15.28571 | |----------------------------------------------------------------------------------| | meansal | | 15 | +----------------------------------------------------------------------------------+ +----------------------------------------------------------------------------------+ 2. | family | person | salary | hours | tall | short | wage | sumwage | sumwage2 | | 1 | 1 | 10 | 5 | 4 | 1 | 2 | 2 | 15.28571 | |----------------------------------------------------------------------------------| | meansal | | 15 | +----------------------------------------------------------------------------------+ +----------------------------------------------------------------------------------+ 3. | family | person | salary | hours | tall | short | wage | sumwage | sumwage2 | | 2 | 2 | 30 | 7 | 5 | 0 | 4.285714 | 15.28571 | 15.28571 | |----------------------------------------------------------------------------------| | meansal | | 30 | +----------------------------------------------------------------------------------+ +----------------------------------------------------------------------------------+ 4. | family | person | salary | hours | tall | short | wage | sumwage | sumwage2 | | 2 | 1 | 30 | 6 | 5.5 | 0 | 5 | 11 | 15.28571 | |----------------------------------------------------------------------------------| | meansal | | 30 | +----------------------------------------------------------------------------------+ . l family person salary meansal +------------------------------------+ | family person salary meansal | |------------------------------------| 1. | 1 2 20 15 | 2. | 1 1 10 15 | 3. | 2 2 30 30 | 4. | 2 1 30 30 | +------------------------------------+ . collapse (mean)salary, by(family) . l +-----------------+ | family salary | |-----------------| 1. | 1 15 | 2. | 2 30 | +-----------------+ . log close name: log: C:\Users\tgindlin\Desktop\class_example.log log type: text closed on: 15 Sep 2016, 18:28:46 --------------------------------------------------------------------------------------------