Split numeric variable based on a decimal

[Al Bothwell]

I have a variable named "ga," which means gestational age. The data is represented in weeks and days. For example, 31.6 means 31 weeks and 6 days. I want to convert the variable into weeks. I am struggling with the appropriate code. Split didn't work since the data is numeric.

Here is a sample of my data:

* Example generated by -dataex-. For more info, type help dataex
clear
input double ga
31.6
31.6
31.5
31.5
30.6
31.4
27.1
27.4
26.3
27.1
26.3
26.2
29.4
29.3
30.4
end

------------------ copy up to and including the previous line ------------------

[Leonardo Guizzetti]

You can use int() and mod() to get the dividend and remainder. These are numerical operation so there's no need to work with strings.

gen ga_weeks = int(ga)
gen ga_days = mod(ga, 1) * 10

gen int total_days = ga_weeks * 7 + ga_days

list, abbrev(20)

Result

     +----------------------------------------+
     |   ga   ga_weeks   ga_days   total_days |
     |----------------------------------------|
  1. | 31.6         31         6          223 |
  2. | 31.6         31         6          223 |
  3. | 31.5         31         5          222 |
  4. | 31.5         31         5          222 |
  5. | 30.6         30         6          216 |
     |----------------------------------------|
  6. | 31.4         31         4          221 |
  7. | 27.1         27         1          190 |
  8. | 27.4         27         4          193 |
  9. | 26.3         26         3          185 |
 10. | 27.1         27         1          190 |
     |----------------------------------------|
 11. | 26.3         26         3          185 |
 12. | 26.2         26         2          184 |
 13. | 29.4         29         4          207 |
 14. | 29.3         29         3          206 |
 15. | 30.4         30         4          214 |
     +----------------------------------------+

[Bruce Weaver]

I understood the question a bit differently. I.e., I think Al wants the result in (possibly) fractional weeks, like this:

* Number before decimal = weeks.
* Number after decimal = days.
* Wanted:  gestational age in weeks.
generate ga_weeks = int(ga) + (mod(ga, 1) * 10)/7
list, clean noobs

Result:

. list, clean noobs

      ga   ga_weeks  
    31.6   31.85714  
    31.6   31.85714  
    31.5   31.71428  
    31.5   31.71428  
    30.6   30.85714  
    31.4   31.57143  
    27.1   27.14286  
    27.4   27.57143  
    26.3   26.42857  
    27.1   27.14286  
    26.3   26.42857  
    26.2   26.28572  
    29.4   29.57143  
    29.3   29.42857  
    30.4   30.57143

[Al Bothwell]

Leonardo's solution gave me days which I converted into fractional weeks. My intention was to get fractional weeks as Bruce explained, so post #3 was a direct approach. Thank you, both!