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| = Stata Aggregating Data = | = Aggregating Data with Stata = Stata offers several commands for computing aggregated statistics and translating datasets into aggregated formats. |
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| == Contract == | == Statistics == |
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| '''`collapse`''' is ideal for aggregated statistics. | The [[Stata/Summarize|-summarize-]] command computes and [[Stata/StoredResults|stores]] descriptive statistics. The [[Stata/Inspect|-inspect-]] command is useful for interactive exploration. The [[Stata/Contract|-contract-]] and [[Stata/Collapse|-collapse-]] commands create datasets of aggregated statistics. The former is useful for descriptive statistics, while the latter is designed for summary statistics. |
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| contract VAR, freq(Count) percent(Percentage) | contract foo, freq(Count) percent(Percentage) |
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| == Collapse == | == Wide and Long Data == The [[Stata/Reshape|-reshape-]] command can be used to translate datasets between wide and long formats. To translate into a wide format, try: {{{ reshape wide VARSTUB, i(KEYVAR) j(GROUPVAR) }}} A series of variables named like `VARSTUB*` will be created, for each group of `GROUPVAR`. To translate into a long format, try: {{{ reshape long VARSTUB, i(KEYVAR) j(GROUPVAR) }}} The variable `VARSTUB` will be created from the variable list `VARSTUB*`, and `GROUPVAR` will be created to indicate the source of `VARSTUB`. |
Aggregating Data with Stata
Stata offers several commands for computing aggregated statistics and translating datasets into aggregated formats.
Statistics
The -summarize- command computes and stores descriptive statistics.
The -inspect- command is useful for interactive exploration.
The -contract- and -collapse- commands create datasets of aggregated statistics. The former is useful for descriptive statistics, while the latter is designed for summary statistics.
contract foo, freq(Count) percent(Percentage)
Wide and Long Data
The -reshape- command can be used to translate datasets between wide and long formats.
To translate into a wide format, try:
reshape wide VARSTUB, i(KEYVAR) j(GROUPVAR)
A series of variables named like VARSTUB* will be created, for each group of GROUPVAR.
To translate into a long format, try:
reshape long VARSTUB, i(KEYVAR) j(GROUPVAR)
The variable VARSTUB will be created from the variable list VARSTUB*, and GROUPVAR will be created to indicate the source of VARSTUB.