Should I correct a course assignment that I already presented? I'm not sure whether the professor will notice the error In a subject of my master we did a team work (analyse a piece of data). All the teams deliver the slides for the presentation the same day even if we presented it in different days. This work is 40% of the subject's grade.

Two hours before our presentation, we found a big mistake in our analysis. Some plots showed incorrect axes if we did filter data correctly, either data wasn't correct or the plot. The data should be above 1 and in the graph the log in base 10 was below 0. We couldn't modify the presentation, so we presented as we intended before finding the error. Nobody (noticed) asked about the mistake. The professor did take notes about the presentation conclusions but were about ones (presumably) not affected by the error.  

We couldn't find in two hours the source of the error although my guess is that is in one of the very first steps of filtering data or in the plotting process, and we were more nervous concerned about the presentation itself. 

I am unsure how to proceed:


Should I correct the work?
It was my mistake I was the one creating the script to analyse the data and I am interested/curious in the correct results. First finding the error, then correcting and creating the slides/plots corrected could take 2 weeks.
Should I contact the professor after correcting the error?
From my point of view we have already presented it and we will receive our grade, from the presentation we did. I would be surprised if we had an appointment to present the corrected version. The next expected contact with this professor is on the final exam (60% of the grade).
How can these affect our/my grade?
I am afraid the professor finds out the mistake and we find out later that we have a low mark or if we send a corrected version our grade will also suffer from it.


I am aware of these other question but my work is not published, nor it will.
How can these affect our/my grade?  



If you do not present the error, it can only be negligible or negative.  I do not see a positive outcome without additional influence.



  Should I contact the professor after correcting the error?  



You state that the next line of communication will be at the Final?  The Final would be too late.  If you're going to do it, then time should be of the essence.  



  Should I correct the work?  



That wholly depends on what the professor would want.  Write a brand-new report?  No.  Show that you understand what the issue was, how it happened, and what a 'fix' would entail?  To the best of your ability, absolutely.  You're presenting a problem, and giving a solution -- not presenting a problem, and expecting a solution on a silver platter.

Regardless of if the professor noticed the error, it would be unwise to punch enough holes in your presentation to render it invalid while you're giving it.  

I've messed-up on some trivial components before.  Communication works wonders.  If you're unhappy with the turn out after working-it-out; then take it to someone else.

Good luck.