During my PhD interview, due to my good computing skills, I was told I would have worked on the code we use _and_ on the phyiscal analysis of its results.

After more than a year, all problems I discussed with my supervisors (and solved) are _only_ performance technicality about the code we use.

I actually love to code/think of new algorithms and implement improvement, so days are actually flowing pretty productively. And this is why I put in the title "I do not like _so_ much".

Being just productive and useful does not make me really happy.

I'd love to co-operate on the phyisical analysis of our results. And the fact that I am missing the opportunity on working on this sied of our scientific research, demoralizes me.

After all this time I am only "the guy who works on the code" to which no one asks any question related to the phyisical results.

You may tell me to "just" talk with my supervisor about my willing to move to a slightly different direction (since it was even been promised to me). Well, I tried to do it (very shyly I admit), and every time he became vague and do not reply.

In conclusion:
have you ever found yourself in the situation? or in the situation you needed to completely change field? what have you done?

I know all situations and people involved are different, but I could still learn something from your experience.

Yep, you're right, my advice is to push your supervisor to let you work in the area that you want to.

Maybe if there's something small you can work on and show him, so that he knows that you can do it?

Also, try to think about the reasons that he may want you to only work on the code and think how this can be overcome?

I'd say bring it up with your supervisor, if you're working on something that isn't totally what you'd like it to be then it could be a *long* process to live with for the rest of your PhD.

Someone in my research team came with the intention of writing one PhD, it evolved, his supervisor directed him in a path he wasn't happy with, he eventually said so and by the end of his first year he'd essentially started his PhD three times before settling on what he wanted.

Thanks for the suggestions so far. I definley have to build up the "strenght" (I am actually quite shy in this field) and have a proper conversation with my supervisor.