[zitterbewegung]

I think this could be done much better by putting a very restrictive license like GPLv3 / AGPL and then in the README putting in that I don't support this project at all and ignore everything associated with wherever you are hosting it.

Using this license would actually make me suspect that your results aren't even valid and I don't trust many experiments that don't release source code.

[HenrikB]

In case OP, and others don't know, it is the copyright holders that can decide on the license. Copyright holders are the persons who contributed to the code. In this case, it sounds like OP is the sole author and therefore the sole copyright holder.

You cannot change the past, but as a copyright holder, you can always set a new license for future releases.

Thus, OP, if you're uncertain, I definitely was when I started out, go with a restrive license as recommended here (GPL). That, together with publishing the code online (e.g. GitHub, Gitlab, ...) as well as a with your article, will give you some protection against plagiarism. Anyone who use include parts of your code for their research code, will have to share theirs code the same. If you later on feel like you want to relax the license, you can always change it to, say, MIT.