Yet Another Day at the Office

10 inches of fresh powder made this morning's ride into a real workout, with lots of falls and desperate saves I think I earned my whiskey tonight.

Just Another Day at the Office.

Here're some pictures from today's commute. It was super nice at 7:30, hence the completely inappropriate dress.

Two Days at the Dregs

Day One:

Henry asked me to go check out his project up at the Dregs, he said he'd bolted a pretty and hard arete. Given the fact that almost every 'arete' in Bozeman is more of a rounded prow I was pretty skeptical. It turns out that I was wrong to doubt Henry's assessment, he bolted what must be one of the sharpest overhanging aretes I've ever seen.

The Incisor as seen from the trail. It's the downhill side of that big hanging block behind the tree.

This is the stellar view from the main wall of climbs at the Dregs, unlike other areas in Gallatin Canyon there's almost no river or car noise up here.

Henry just after whipping from his day one high point.

The Incisor Arete is brutally hard, with a crux only 20ft tall it's amazing how full body tired you get trying it. Your hands are tired of pinching and crimping, your forearms and biceps are burning from long moves and slaps on small holds, your legs are shaking from trying to wrap the arete with your left thigh while standing on it with your right foot, and your mind is whimpering that the whole thing is going to fall over like a giant cleaver.

Day Two:
Yesterday when Henry suggested we go back up to the Incisor I was pretty sure we'd end up freezing our butts off at the cave instead. Fortunately more psyched heads prevailed and we ended up hiking up and having a great session.

 The stick was a life saver on the S2 approach, although crampons would have been better.

Henry forgot his harness so he climbed all day in this full body maternity harness.

 Here's the traverse over from the base of the main wall to 'Count Dracula', which is both the warm-up and has the rappel anchor to get down to the Incisor. 

Here's Henry belaying me over to the base of the Count, note the obligatory hip belay, because if you're short roping snowy traverses gri-gris are bad form. There aren't any pictures after this (cold fingers), but we both had a couple good burns at the Incisor. Henry was able to make another high point and then surpass it. He was essentially through the crux, so I'm sure he's hoping for a day just a couple degrees warmer for the send. I managed all the moves, now I'll have to start giving it redpoint burns. We're both thinking it's someplace near 13b. I'm a bit out of shape, but it seems to be quite a bit harder than Hantavirus at the cave.

LaTeX DynaLite

I'm giving a DynaLite on the very useful LaTeX typesetting language later today, so I thought I'd put my talk here so that anyone who wanted it could see it. It should be noted that the header in the talk is not the whole header I used in the tex file, but I think the only missing items are the Beamer theme information.

Here's the pdf.

Here's the tex file.

Lattès Example

I gave a DynaLite on the Lattès example last week and given the shortage of information on the web I'm posting my notes. This is a more algebraic geometry perspective than those offered in Beardon and Carleson/Gamelin, it somewhat follows insight from Milnor. Here are my notes which are somewhat out of order, and here is a helpful picture of a torus generated with the following tikz code. The clip function is really handy, and you can put things outside the clipped box by just inserting the code for them prior to the clip command.

\begin{tikzpicture}[scale=1.5]

      %Clip

      \clip (-3,-3) rectangle (3,3);

      

      %Horizontals

      \foreach \x in {-2,-1,...,2}

 \draw[-] (3.000000,\x) -- (-3.000000,\x);

    

      %Slants slope = .61825

      \foreach \x in {-5,-4,...,5}

 \draw[-] (2+\x,2*1.61825) -- (-2+\x,2*-1.61825);

 

      %Fills

      \fill[green!20!white] (0,0) -- (1,0) --   (1.61825,1) --(.61825,1) --cycle;

      \fill[blue!20!white] (0,0) -- (-1,0) --   (-1.61825,-1) --(-.61825,-1) --cycle;

      %axis

      \draw[<->][red] (3,0) -- (-3,0);

      \draw[<->][red] (0,3) -- (0,-3);

\end{tikzpicture}

Diophantine Numbers

I spent a while today writing up this little primer on Diophantine numbers. It's mostly the coverage Milnor gives in chapter 11 of Dynamics in One Complex Variable, but I've added some details and included the solution to 11-a.

It's probably riddled with typos and logical errors, feel free to correct in the comments.

Trickzy Tikz

So I wanted to make a regular 30-gon in tikz, but was way too lazy to work out the coordinates for each vertex on my own, so here's what I came up with:

Write a file called regpoly.c containing

#include <math.h>
#include <stdio.h>

int main(int argc, char *argv[])
{
int i=0;
double r=2;
double n= 30;
for (i = 0; i < n; i++) {
  printf("\\draw[-] (%f,%f) -- (%f,%f);\n",r * cos(2 * M_PI * i / n), r * sin(2 * M_PI * i / n), r * cos(2 * M_PI * (i+1)/ n), r * sin(2 * M_PI * (i+1)/ n));
}
return 0;
}

compile it in the terminal by typing

cc regpoly.c -o regpoly -lm

run it by typing

./regpoly

Copy the resulting output into a tikzpicture in latex. Clearly one can change the number of sides the gon has by replacing 30 in line 8. Note that wordwrap has made line 10 into two lines here, it needs to be only one for it to run.

R make command not found linux

I'm posting this because I've just found the solution to a really silly little issue basically without the help of any of the online discussions I was able to find.

The issue was installing the 'vegan' package in R on Arch Linux. All the errors are versions of

make: command not found

This is of course appearing because you don't have the 'make' command installed, so the R package 'vegan' and it's prerequisite 'rgl' won't work without it. To fix this you need to type the following:

pacman -S base-devel
pacman -S gcc
pacman -S gcc-fortran

The make command for bash is in the base-devel group, the one for C+ is in gcc, and the one for fortran is in gcc-fortran.