#Stata create new variable generator#

In addition to allowing multiple data sets to be open at a time, we can link frames together such that rows of data in each frames are connected to each-other and can inter-operate. Note that clear frames is an alias for frame reset and functions as well. To drop all frames and their data, and reset Stata to a single вЂњdefaultвЂќ frame, You cannot drop the frame you are currently in. This process is non-destructive, so there is no harm in running it.

While not a new command to Stata 16, the compress command can be very handy as it will attempt to shrink the size of the data as much as possible. That means if you open multiple very large data sets in frames, you can quickly run out of memory when you never had before.ДЇrames can be dropped via frame drop as you might guess.

When you have data loaded into a frame, it is (like all data in Stata) loaded into your memory. Note also that frame dir will track which frames have data that needs to be saved. Note that most data sets which are not provided by Stata will likely not have a data label, so you can add one as desired. We see that the output of frame dir is changed. Note: frames marked with * contain unsaved data The description next to each frame is set via label data, a previously not very useful trait that takes on new important in keeping track of which data is loaded in which frame. Now we can see what size the data is in each frame. Maindata 240 x 5 fictional blood-pressure data LetвЂ™s load some data to make this more interesting. The 0 x 0 is telling us that in neither frame has any data loaded. We can keep track of all our frames via frame dir. Notice that the last command failed we must create a frame before we can switch to it. We can jump between frames via frame change. Notice that weвЂ™re still in the вЂњmaindataвЂќ frame. We can create a second data frame as well. There is nothing special about this name, we can easily rename the frame. This tells us the name of the frame, the name of a new frame when starting Stata is вЂњdefaultвЂќ. By itself, it will remind you of the current frame: Try new ways to create variables and be sure to read the help files.The primary command for dealing with frames is, unsurprisingly, frame (or frames, either works). You can also use the egen command to create new variables. IвЂ™ve just touched on the ways you can create new variables. This will create a new variable that runs from 1 to 52 for domestic cars and 1 to 22 for foreign cars. You can combine this with by to create an index within another variable. This will create a new variable that runs from 1 to 74. You can use the _n operator to create a variable that indexes the observation number. generate random = rnormal()Д¬reate a New Variable that Indexes the Observations

#Stata create new variable generator#

The random normal generator command is rnormal() (it defaults to a mean of 0 and standard deviation of 1 and it will draw as many values as there are observations in the dataset). LetвЂ™s create a new variable whose values will be random draws from a normal distribution with a mean of 0 and a standard deviation of 1. We can create a new variable that is a random draw from a distribution. New Variable that is a Random Draw from a Distribution

If a line in the data is associated with foreign cars the new obs variable will have a value of 22 and domestic cars will have a value of 52. That is, we are going to get the number of foreign cars and the number of domestic cars. This will create a variable that is a constant within the levels of foreign. For example, we can type: by foreign: generate obs = _N If you combine this with by you can create a new variable that will be equal to the number of observations within the levels of the by variable. You can use the _N operator to create a new variable that is equal to the number of observations in a dataset.