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| Stata offers human-readable variable names, variable labels, variable printing formats, and value labels. Stata stores variable labels and value labels in a separate database. Many built-in commands seamlessly pull in metadata from that database, but there are notable exceptions. |
Stata exposes a rich API for querying internal '''metadata'''. |
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| == Variable Labels == | == Labels == |
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| Variable labels are defined using the '''`label`''' command. | Variable and value labels are primarily manipulated by the [[Stata/Label|`-label-`]] command. |
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| label variable foo "bar" | . label variable foo "yes or no?" . label define yesno 1 "Yes" 0 "No" . label values foo yesno . label list yesno yesno: 0 No 1 Yes |
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| Variable metadata including labels can be inspected and exported using the '''`describe`''' command. | Numeric values can be quickly prepended to value labels using the '''`-numlabel-`''' command. |
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| preserve describe, replace assert varlab=="bar" if name=="foo" restore |
numlabel foo, add mask("#. ") }}} To access or store the text of a variable label, try: {{{ local varlab_foo: variable label foo }}} To manipulate value labels, try: {{{ local vallab_foo: value label foo local vallab_foo_1: label `vallab_foo' 1, strict |
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| == Value Labels == Variable labels are defined using the '''`label`''' command. However, they must first be defined as a label and then linked to one or more variables. |
== Descriptives == |
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| label define baz 0 "No" 1 "Yes" label define baz 99 "Missing", modify label values foo baz }}} By default, labels cannot be overwritten. The '''`add`''' option allows new values to be inserted into an existing label. The '''`replace`''' option allows existing values to be overwritten in an existing label. The '''`modify`''' option combines both. Numeric values can be added to value labels using the '''`numlabel`''' command. {{{ numlabel baz, add mask("#. ") }}} ---- == Quick Tips == Stata has a number of interactive tools for examining metadata. {{{ di _N // number of cases di c(k) // number of variables |
display _N // number of cases display c(k) // number of variables |
Stata Metadata
Stata exposes a rich API for querying internal metadata.
Contents
Labels
Variable and value labels are primarily manipulated by the `-label-` command.
. label variable foo "yes or no?"
. label define yesno 1 "Yes" 0 "No"
. label values foo yesno
. label list yesno
yesno:
0 No
1 YesNumeric values can be quickly prepended to value labels using the -numlabel- command.
numlabel foo, add mask("#. ")To access or store the text of a variable label, try:
local varlab_foo: variable label foo
To manipulate value labels, try:
local vallab_foo: value label foo local vallab_foo_1: label `vallab_foo' 1, strict
Descriptives
display _N // number of cases display c(k) // number of variables