Unexpected error: factor variables may not contain noninteger values

[Merette Martens]

Hi, When executing a linear regression with an interaction term, I’m getting an unexpected error message from Stata: factor variables may not contain noninteger values.
I'm using Stata 17.0 for Windows.

I know that this question has been asked before on this forum, however, when I tried all the answers, the error remains.
In a normal regression, Stata runs without problems. It is only when I add the interaction term that I keep getting this error.
The fact is; the variables that I am trying to test for their interaction term are containing noninteger values.
Is there a possibility to keep the numbers with decimals or should I create new variables containing only whole numbers?
And if so, how do I create a new variable in Stata containing no decimals?

Thanks in advance,

[Maxence Morlet]

add the prefix c. if the variable you are interacting is continuous or i. if it is categorical (e.g. binary)

[William Lisowski]

And in doing what Maxence Morlet recommends, take a few minutes to read the output of

help factor variables

to understand the basics of factor variable notation like "i.varname" and "c.varname"

[Merette Martens]

Hi Maxence Morlet and William Lisowski, thank you so much for taking the time to reply to my post.
Unfortunately, the variable that I am trying to use is in fact a continuous variable.
So I tried using the c. before the variable, however, if I run that regression, I end up with numerous rows, showing me per category.

I also tried the following:
format varname %2.0f

But unfortunately, I still get the same error over and over again.
i. before the variable remains in the same error: factor variables may not contain noninteger values.

How come Stata still thinks there are noninteger values when I transferred the values to no decimals?

Thanks in advance!

[Merette Martens]

Hi,
It already worked, I added the c. before each of the 2 interaction variables which caused me to only have 1 regression variable.
Thanks for your advice!