topic Re: Converting binomial variables with Yes/No into variables that display 1/0 in New SAS User

Converting binomial variables with Yes/No into variables that display 1/0

u58469353 — Sun, 21 Nov 2021 19:49:29 GMT

I am trying to perform logistic regression on a dataset that contains several binomial variables. How do I convert multiple variables with "yes" and "no" as the only inputs to "0" and "1"?

I have looked at some other questions on here where users asked similar questions, however, I can't seem to get it to work. When I tried, all of the values for the variable changed to 1, with no values showing 0.

Re: Converting binomial variables with Yes/No into variables that display 1/0

Tom — Sun, 21 Nov 2021 20:59:21 GMT

Let's assume you mean a binary variable. (A binomial variable is a number that represents the count, or sum, of a series of binary variables. In other words a variable whose values follow a binomial distribution.).

If the variable contains text like YES or No then you cannot convert it into a number in the same variable. You can either convert the strings '1' an '0'. Or make a new variable.

Here is simple conversion that takes advantage of the fact that SAS will evaluate boolean expressions to 1 when True and 0 when false.

data want;
  set have;
  new_var = old_var= 'yes';
run;

But be careful. Are the values only exact 'yes' or 'no'? Do you ever have missing values? If so this code will convert those to zero (false) instead of missing. Is the case of the string consistent? Do you ever have 'Yes' or 'YES' or 'Y' or 'y' instead of 'yes'?

Re: Converting binomial variables with Yes/No into variables that display 1/0

u58469353 — Sun, 21 Nov 2021 21:33:20 GMT

All of the values in the field are either 'Yes' or 'No'

Re: Converting binomial variables with Yes/No into variables that display 1/0

u58469353 — Sun, 21 Nov 2021 21:34:03 GMT

All of the values for the variable are wither 'Yes' or 'No'

Re: Converting binomial variables with Yes/No into variables that display 1/0

u58469353 — Sun, 21 Nov 2021 22:19:31 GMT

This does not work. Causes all values in the new variable to be 0

Re: Converting binomial variables with Yes/No into variables that display 1/0

PaigeMiller — Sun, 21 Nov 2021 22:58:22 GMT

@u58469353 wrote:

I am trying to perform logistic regression on a dataset that contains several binomial variables. How do I convert multiple variables with "yes" and "no" as the only inputs to "0" and "1"?

I have looked at some other questions on here where users asked similar questions, however, I can't seem to get it to work. When I tried, all of the values for the variable changed to 1, with no values showing 0.

For a Logistic regression, you should not have to convert anything. "yes" and "no" should work fine without creating 0 and 1. So make your life simple, don't create the 0 and 1 variable. (How easy is that?)

Re: Converting binomial variables with Yes/No into variables that display 1/0

PaigeMiller — Mon, 22 Nov 2021 11:27:55 GMT

@u58469353 wrote:

All of the values for the variable are wither 'Yes' or 'No'

Please examine your data and the code you are using very very carefully. 'Yes' is not the same as 'yes'. Can you see the difference?

Re: Converting binomial variables with Yes/No into variables that display 1/0

Kurt_Bremser — Mon, 22 Nov 2021 06:17:00 GMT

Please post your code in a code box.