Introduction to Stata 8

In commands that have a dependent variable, it is the first in the varlist:
oneway bmi sex bmi is the dependent variable
regression bmi sex age bmi is the dependent variable
scatter weight height scatterplot, weight is y-axis
tabulate expos case The first variable defines the rows
Conditional commands. The if qualifier [U] 14.1.3.
The operators used in conditions are defined in section 10.1. Here are a few examples:
summarize age if sex==1 statistics for males only
list id age if age < 35 list only if age < 35
replace npreg=. if sex==1 set npreg to missing for males
Numeric ranges. [U] 14.1.4
Numeric ranges are marked by a slash:
recode age (1/9.999=1)(10/19.999=2) , generate(agegrp)
list sex age weight in 1/10 // observations 1 to 10
Number lists. The in qualifier [U] 14.1.8
A number list (numlist) is a list of numbers; there are some shorthand possibilities:
1(3)11 means 1 4 7 10
1(1)4 4.5(0.5)6 means 1 2 3 4 4.5 5 5.5 6
4 3 2 7(-1)1 means 4 3 2 7 6 5 4 3 2 1 (Danish CPR number test)
1/5 means 1 2 3 4 5
4/2 7/1 means 4 3 2 7 6 5 4 3 2 1 (Danish CPR number test)
Example:
list sex age weight in 1/10 // observations 1 to 10
twoway line mort year , xlabel(1900(20)2000) // x-axis labels
Weighting observations [U] 14.1.6, [U] 23.13
A typical use is to 'multiply' observations when the input is tabular:
Cases Controls
Exposed 21 30
Unexposed 23 100
Total 44 130
. input expos case pop // see section 8
1 1 21
1 0 30
0 1 23
0 0 100
. end
. tabulate expos case [fweight=pop] , chi2 // see section 11.1
. cc expos case [fweight=pop] // see section 11.1
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