removing text from string variable with date format

[Sophon Yen]

Hello, I have a string variable that looks like this: 13-03-2014(Late visited). How can I remove some kind of those texts from this variable and then convert this variable to date type. Thanks in advance.

[Clyde Schechter]

I don't think anybody can help you with this; too much is left to the imagination. What "kind of those texts" do you want to remove from the variable? And how is the variable actually represented in Stata? Never mind what it looks like to your eyes. That's irrelevant--the actual Stata internal data is what matters.

To get useful advice, please post back with example data using the -dataex- command. If you are running version 17, 16 or a fully updated version 15.1 or 14.2, -dataex- is already part of your official Stata installation. If not, run -ssc install dataex- to get it. Either way, run -help dataex- to read the simple instructions for using it. -dataex- will save you time; it is easier and quicker than typing out tables. It includes complete information about aspects of the data that are often critical to answering your question but cannot be seen from tabular displays or screenshots. It also makes it possible for those who want to help you to create a faithful representation of your example to try out their code, which in turn makes it more likely that their answer will actually work in your data.

Also explain exactly what you want to do with the data--showing what you want the results to look like may be the most effective way.

[Ali Atia]

Assuming the date part of the string is in a consistent format across observations (dd-mm-yyyy), this should do the trick:

gen date = date(ustrregexs(0),"DMY") if ustrregexm(var1,"\d{2}-\d{2}-\d{4}")

Otherwise, please post back following the advice in #2.

[William Lisowski]

Let me make a simplifying assumption here. If the date always appears at the beginning of the text, and always has the day followed by the month followed by the year, with optional text afterwards, then the following example demonstrates useful technique.

. generate date = daily(datestr,"DMY#")

. format %td date

. list, noobs

  +--------------------------------------+
  |                  datestr        date |
  |--------------------------------------|
  | 13-03-2014(Late visited)   13mar2014 |
  +--------------------------------------+

But to be honest, this string looks like it was taken from a free-form data entry field, where the date and comments were entered in whatever way the person collecting the data chose to enter the information. That is why it is so important that you show real data examples that illustrate the variability in your data.

[William Lisowski]

Perhaps this example will start you in a useful direction.

capture program drop myreg
program define myreg
    local name `1'
    macro shift
    regress `*'
    estimates store `name'
end

sysuse auto, clear
myreg m1 price weight
myreg m2 price weight length
estimates dir

. myreg m1 price weight

      Source |       SS           df       MS      Number of obs   =        74
-------------+----------------------------------   F(1, 72)        =     29.42
       Model |   184233937         1   184233937   Prob > F        =    0.0000
    Residual |   450831459        72  6261548.04   R-squared       =    0.2901
-------------+----------------------------------   Adj R-squared   =    0.2802
       Total |   635065396        73  8699525.97   Root MSE        =    2502.3

------------------------------------------------------------------------------
       price | Coefficient  Std. err.      t    P>|t|     [95% conf. interval]
-------------+----------------------------------------------------------------
      weight |   2.044063   .3768341     5.42   0.000     1.292857    2.795268
       _cons |  -6.707353    1174.43    -0.01   0.995     -2347.89    2334.475
------------------------------------------------------------------------------

. myreg m2 price weight length

      Source |       SS           df       MS      Number of obs   =        74
-------------+----------------------------------   F(2, 71)        =     18.91
       Model |   220725280         2   110362640   Prob > F        =    0.0000
    Residual |   414340116        71  5835776.28   R-squared       =    0.3476
-------------+----------------------------------   Adj R-squared   =    0.3292
       Total |   635065396        73  8699525.97   Root MSE        =    2415.7

------------------------------------------------------------------------------
       price | Coefficient  Std. err.      t    P>|t|     [95% conf. interval]
-------------+----------------------------------------------------------------
      weight |   4.699065   1.122339     4.19   0.000     2.461184    6.936946
      length |  -97.96031    39.1746    -2.50   0.015    -176.0722   -19.84838
       _cons |   10386.54   4308.159     2.41   0.019     1796.316    18976.76
------------------------------------------------------------------------------

. estimates dir

----------------------------------------------------------------
             |           Dependent  Number of        
        Name | Command    variable     param.  Title 
-------------+--------------------------------------------------
          m1 | regress       price          2  Linear regression
          m2 | regress       price          3  Linear regression
----------------------------------------------------------------

The Stata Programming Reference Manual PDF included in your Stata installation and accessible through Stata's Help menu is your guide to learning about writing programs in Stata.

[Sophon Yen]

@Clyde Schechter Thank you so much for your advice for how to post problem in the forum to get what I want from the data that I want to do with, Thanks Ali Atia and William Lisowski for your helps and It's nicely work. Thanks all you guys!

Best regards,
Sophon

[William Lisowski]

Post #5 above belonged in a different topic, I do not know how it came to be posted here. My apologies.

[Ches Zin]

Dear Statalisters,
My apologies. I just have the same query as post#1 on removing the date from the string variables. Below is the example. I want to remove "15 january 2016" and " 2014-07-03" from these string variables. Any help is highly appreciated.
Thanks

input str109 doser
"One tablet 3 times daily. Next dose 15 januari 2016."
"0.5 -1 tablet when needed for pain. Max 2 tab per day, till 2014-07-03"