Category Archives: Uncategorized

So you want me to write a recommendation

It’s part of my job to write recommendation letters for students. I’ve written letters for students who want to tutor in math and for those applying to graduate school. I’ve found that some students give me all the information I need to write a letter and some that don’t, so I’ve written some general advice for letter seekers.

First of all, don’t be afraid to ask for a letter. I am happy to write a letter* because I want you to see you succeed. (*Disclaimer: I have occasionally been asked for a letter from students whom I do not know well, and I have encouraged them to seek a letter from another professor who know them better and can write a more effective letter).

Please give me advance notice. It is hard to write a good letter, and it takes time. Please give at least two weeks advance notice. It is ok to remind me of upcoming deadlines.

Provide me with your CV or resume and any essays you have prepared for your application. Also, I would like a short description of the programs you are applying for and what you hope to gain from those programs. These things will help me write your recommendation, and I might provide comments on your application materials.

Sage, Macaulay2, and my delta_1 calculator

The Sage worksheet delta-one-via-gröbner-basis.sws allows you to input a knot and calculate \(\delta_1\) of that knot.  See my paper for a definition of \(\delta_1\) and a description of the algorithm.  To get this worksheet to run, you need to download

Go ahead and install Sage.

Before you install Macaulay2, please read this entire paragraph.  I ran into a problem here using Mac OS 10.8.  Macaulay2 has an installation procedure that didn’t play nice with my Sage installation.  The rest of the paragraph is dedicated to my solution.  From a completely Macaulay2 free state (I had to remove some configuration files created by the Macaulay2 installer), I downloaded Macaulay2 and stored the folder in /Applications.  In the terminal, I created a symbolic link in /usr/bin/ to the Macaulay2 executible (M2) via the command ‘sudo ln -s /Applications/Macaulay2-1.4/bin/M2 /usr/bin/M2’.  Your /path/to/M2 might be slightly different depending on where you put the Macaulay2 folder and what version you downloaded.  Now at this point the terminal command ‘M2’ runs Macaulay2, and Macaulay2 works inside of the Sage notebook interface.

To check that Sage and Macaulay2 are compatible, execute the command ‘macaulay2(‘2+3′)’ in the Sage notebook.  If it returns 5, then things are probably working.  If there is an error message, I might be able to help but will probably send you to the Sage or Macaulay2 Google Group pages.

 

Once Macaulay2 is working inside Sage, upload the delta-one-via-gröbner-basis.sws worksheet into the Sage notebook interface.  There you can see some examples of a \(\delta_1\) calculation and learn how to compute \(\delta_1\) for any examples you wish.

welcome

MAT 761 students cand find the course webpage here.

Please visit my main site at http://pdhorn.mysite.syr.edu.

MAT 761 students cand find the course webpage here.

Please visit my main site at http://pdhorn.mysite.syr.edu.

MAT 761 students cand find the course webpage here.

Please visit my main site at http://pdhorn.mysite.syr.edu.

MAT 761 students cand find the course webpage here.

Please visit my main site at http://pdhorn.mysite.syr.edu.

MAT 761 students cand find the course webpage here.

Please visit my main site at http://pdhorn.mysite.syr.edu.

MAT 761 students cand find the course webpage here.

Please visit my main site at http://pdhorn.mysite.syr.edu.

MAT 761 students cand find the course webpage here.

Please visit my main site at http://pdhorn.mysite.syr.edu.

MAT 761 students cand find the course webpage here.

Please visit my main site at http://pdhorn.mysite.syr.edu.