topic Re: Removing an alpha character from the first place in an ID to change the ID to numeric in SAS Programming

Removing an alpha character from the first place in an ID to change the ID to numeric

wlierman — Wed, 03 Nov 2021 18:02:26 GMT

I am wanting to convert a series of ID values that are formatted as text to numeric using

Data SASCHART.Date_Fix_Data (drop = Contact_Person_ID);
  Retain Day_mon Case_ID County Day_mon1 Contact_Person_ID County_T;
  Set SASCHART.Date_Fix_Data;
  Contact_ID = input(Contact_Person_ID, 8.);
run;

The vast majority of the entries in Contact_Person_ID field are all numbers like

54632784

53627928

64538272 and so on.

But there are some entries that begin with an alpha like

A324577

A564732

How do I remove the alpha character in the first place so I am left with just the numbers and can perform the input conversion?

Thank you for your help.

wlierman

Re: Removing an alpha character from the first place in an ID to change the ID to numeric

PaigeMiller — Wed, 03 Nov 2021 18:12:15 GMT

if anyalpha(Contact_Person_ID)=1 then Contact_Person_ID=substr(Contact_Person_ID,2);

Re: Removing an alpha character from the first place in an ID to change the ID to numeric

ballardw — Wed, 03 Nov 2021 18:13:39 GMT

Why do you want an Id variable to be numeric? Are you going to do arithmetic with it? If you aren't doing arithmetic then it is probably better to leave the variable as character.

Here is one example of removing alphabetic characters from a variable.

data example;
  input Contact_Person_ID $ ;
  contact_person_id = compress(Contact_Person_ID,,'a');
datalines;
A324577
A564732
;

Re: Removing an alpha character from the first place in an ID to change the ID to numeric

wlierman — Wed, 03 Nov 2021 19:20:27 GMT

Thank you for the function anyalpha

Re: Removing an alpha character from the first place in an ID to change the ID to numeric

wlierman — Wed, 03 Nov 2021 19:24:35 GMT

I need the numeric form so that I can use the first. last. method to count all individual cases and contacts by day_month over the time frame that Public Health has data from 2020 to current. I then hope to create a line graph of cases and contacts using SAS Graph.

Thank you for the method to remove alpha character.

wlierman

Re: Removing an alpha character from the first place in an ID to change the ID to numeric

Tom — Wed, 03 Nov 2021 19:34:55 GMT

Using BY group processing does not require numeric variables.

proc sort data=sashelp.class out=class;
  by sex age ;
run;

data want;
  set class;
  by sex;
  if first.sex then youngest=name;
  retain youngest;
  if last.sex;
  oldest = name;
  keep sex youngest oldest;
run;

proc print;
run;

Re: Removing an alpha character from the first place in an ID to change the ID to numeric

wlierman — Wed, 03 Nov 2021 19:38:51 GMT

Thank you.

That looks to be a simpler solution to the counting up of cases and contacts.

wlierman

Re: Removing an alpha character from the first place in an ID to change the ID to numeric

Tom — Wed, 03 Nov 2021 19:49:51 GMT

@wlierman wrote:

I need the numeric form so that I can use the first. last. method to count all individual cases and contacts by day_month over the time frame that Public Health has data from 2020 to current. I then hope to create a line graph of cases and contacts using SAS Graph.

You can use the DISTINCT keyword in SQL code. So if you have one record per contact that includes both a DATE and a CASE id then you should be able to use COUNT(*) for number of contacts and COUNT(DISTINCT CASE) as number of cases. Not sure what a day month is, perhaps you want "01-01" for January first?

proc sql;
create want as
  select substr(put(date,yymmdd10.),6) as MMDD 
          , count(distinct cases) as n_cases
          , count(*) as n_contacts
  from have
  group by MMDD
;
quit;

Re: Removing an alpha character from the first place in an ID to change the ID to numeric

wlierman — Wed, 03 Nov 2021 20:43:48 GMT

Thank you for the proc sql code insight.
My data set looks like this

Day_mon     CaseID     County    Day_mon1    Contact_Person_ID    County_T
01MAR20   5463278      Baker     11SEP20            4536272                Yamhill05MAR20   5367382     Jackson   11SEP20           5436275                Washington
and so on.   I need to keep both Day_mon since the data on contacts doesn't begin until Sept 2020whereas cases start in March 2020 and in the data set I am using the last contact is roughly October 12, 2021 while cases run through Oct 22, 2021. Once the graph has been created and everything looks good I am going to refresh both datasets which will then have November data.
With the data I have then I wrote the code as follows:

Proc sql;
Create Table SASCHART.Setup_Case as
Select substr(put(day_mon,yymmdd10.),6) as MMDD
          , count(distinct CaseID) as n_cases
          /*, count(*) as n_contacts*/
from SASCHART.Date_Fix_Data
group by MMDD
;
quit;
but received the following error

ERROR: Numeric format YYMMDD in PUT function requires a numeric argument.

The wanted data set would look like
Day_mon      n_cases         Day_mon1        N_contacts1MAR20              1               11SEP20    355MAR20    9 12SEP20 67

and so on through the end of the time series for each
Your guidance is very appreciated.
wlierman

Re: Removing an alpha character from the first place in an ID to change the ID to numeric

Tom — Wed, 03 Nov 2021 21:11:34 GMT

Your DAY_MON1 variable looks like a date, but apparently it is NOT a date. You can convert it to a date using the INPUT() function. Why is it called "DAY_MON" if it includes day, month and year? Note that if you want to use character strings for dates it is best to use YYMMDD. format instead of others because then lexicographic order will also be chronological order.

So use something like:

create Table SASCHART.Setup_Case as
  select input(day_mon1,date9.) as date format=yymmdd10.
          , count(distinct CaseID) as n_cases
          /*, count(*) as n_contacts*/
  from SASCHART.Date_Fix_Data
  group by 1
;

To count at the individual date level.

If you want to aggregate to MONTH of other time division use INTNX() function to all of the dates in the same interval to the same value.

create Table SASCHART.Setup_Case as
  select intnx('month',input(day_mon1,date9.),0) 
             as month format=yymmd7.
       , count(distinct CaseID) as n_cases_per_month
     /*, count(*) as n_contacts*/
  from SASCHART.Date_Fix_Data
  group by 1
;

Or if you are looking to see months from some base date perhaps you want to use intck() function instead?

create Table SASCHART.Setup_Case as
  select intck('month','01OCT2020'd,input(day_mon1,date9.)) 
             as month_num
       , count(distinct CaseID) as n_cases_per_month
     /*, count(*) as n_contacts*/
  from SASCHART.Date_Fix_Data
  where input(day_mon1,date9.) >= '01OCT2020'd
  group by 1
;

Re: Removing an alpha character from the first place in an ID to change the ID to numeric

wlierman — Wed, 03 Nov 2021 22:32:48 GMT

Tom

Thank you very much. This is the solution that I am needing.I tried indicating as a solution but it is part of a thread that already has a solution.
How can I mark your latest answer as a solution so you can receive the credit for this work?

Since you have helped me tremendously, I have one more step and that is to create a graph.The cases time line has 601 rows that sounds about right since cases were measured from patient 1 on March 1, 2020.Contacts have 396 rows which reflects the effort it took to build up the contact effort from scratch.

The data sets look like this
Cases      Contacts
    date                n_cases                       date                n_contacts

2020-03-01                1       2020-09-11 253
2020-03-05                3                         2020-09-12               350
2020-03-06                5                         2020-09-13               185
      .                                                              .
      .                                                              .
      .                                                              .
2021-06-07              300       2021-06-07 41
      .                                                              .
      .                                                              .
      .                                                              .
2021-10-26            1360       2021-10-12    71

Would SAS graph be able to produce a good graph? Having 601 dates for cases and 396 dates for contactswould make the x-axis illegible. Maybe choosing an interval to show just a few dates. How would you suggest presenting the visualization? Then the contacts time line needs to overlay the cases time line to keep the chronological order.

Again thank you for all your knowledge and experience.

wlierman