Any maths buffs?

Consider the definition of

$
e^x = \Sum_n=0^\infty \frac{x^n}{n!}
$
let
$
x=i \pi
$
play around, split the sum and you might get somewhere at a guess? That would be one initial plan of a attack

V.B need to install a Latex parser now,

Seeing how the 3 concepts behind euler's idendity evolved, namely e, i, and pi, you'd bloody well hope that they'd equal something elegant or we'd all be screwed. Do some complex analysis on it and it'll all become obvious (and boring, so very very boring).

Ummm, it may just be your lack of explanantion, but WTF? This here smells of a mixture of bullshit and crack pipe.

V.B need to install a Latex parser now,

true dat, I really find it hard to read the notation.

Yeh me too. Here's whats happening,

I've extracted some data from a netCDF file (this took me long enough to figure out), and it's in matrix form with each element containing a location in latitude and longitude along with the temperature at that point. I can currently get matlab to plot the temperature in pure grid form if the matrix was evenly distributed across the globe but i can't figure out how to get it to locate each point to the lat and lon associated with it. I'm doing all this with the mapping tool box.

No worries if you can't figure it out, I'll just ask someone when I next go into uni.

this should be pretty trivial, although saying that i'm extremely rusty with matlab and may be misremembering. drop a pm with more details if you like

this thread's brilliant. i haven't understood a single thing of the last dozen or so posts.

@harold Use IDL everyone I know who has done plots like that uses IDL.

@ TheBrick(Tommy) - did you do a PhD at LSE?

Ummm, it may just be your lack of explanantion, but WTF? This here smells of a mixture of bullshit and crack pipe.

No, coffee and a dislike of complex analysis. /expi /pi makes more sense when considering the roots of unity.

Didn't De moivre show that; Cos(x)^n = Re((Cos(x) + iSin(x))^n) = Re(e^ix)?
And similarly that Sin(x) was the Imaginary part of the above?

Didn't De moivre show that; Cos(x)^n = Re((Cos(x) + iSin(x))^n) = Re(e^ix)?
And similarly that Sin(x) was the Imaginary part of the above?

I don't think so. he only showed the first of your two equalities. Not the second, which is Euler.

http://en.wikipedia.org/wiki/De_Moivre's_formula (not gonna post this again: click it Tim!)

@tommy, yeh I've been told that too. The only thing is that I can get matlab free at the moment and one of the post docs does it all with matlab so i'm having a try. Might just ask the department to buy me an IDL licence if it gets too tricky.

Ha! you will not get an IDL license for yourself! They are about £10k I think. You can download a student edition or something for free that allows you to test you code then ssh into a machine with a full IDL license to run and output your data. I think socrates might have a license but your better off finding out if there is one with in your group has one or access to one.

Mashton, insert this into http://nirvana.informatik.uni-halle.de/~thuering/php/latex-online/latex.php
which should give

http://nirvana.informatik.uni-halle.de/~thuering/php/latex-online/olatex_160050.png

\documentclass[11pt]{report}
\begin{document}
Consider the definition of

[
e^x = \sum_{n=0}^\infty \frac{x^n}{n!}
]
let
[
x=i \pi
]
play around, split the sum and you might get somewhere at a guess? That would be one initial plan of a attack
\end{document}

Personally I would encourage anyone to learn and use Latex not just for maths stuff, the quality of the document compared to word is an entirely different league. Word documents just look shit in comparison.

Yeh me too. Here's whats happening,

I've extracted some data from a netCDF file (this took me long enough to figure out), and it's in matrix form with each element containing a location in latitude and longitude along with the temperature at that point. I can currently get matlab to plot the temperature in pure grid form if the matrix was evenly distributed across the globe but i can't figure out how to get it to locate each point to the lat and lon associated with it. I'm doing all this with the mapping tool box.

No worries if you can't figure it out, I'll just ask someone when I next go into uni.

persevere with matlab. it's a great tool.
you need to sort your data into 3x 2d vectors (lat, long, temp)
use
axesm('mercator')
pcolorm(lat,long,temp);
demcmap(temp);

can't test this as i no longer have a license - check here for more details about pcolorm

Ace thread. I'm just getting back into maths, I want to do an OU degree in Engineering and must do a hardcore maths unit as the the first course

fuck yeh, cheers, that saved me a load of time!

persevere with matlab. it's a great tool.
you need to sort your data into 3x 2d vectors (lat, long, temp)
use
axesm('mercator')
pcolorm(lat,long,temp);
demcmap(temp);

can't test this as i no longer have a license - check here for more details about pcolorm

1 Attachment

hey, just checked your derivative and it's wrong, cos you forgot to do v*du/dx for the "-2xy" term.... that is probably why you're getting a funny answer

For playing with stuff thsi site is good it has stuff accessible to all levels and challenging to all.

http://www.math.hmc.edu/funfacts/ffiles/10006.8.shtml

http://www.math.hmc.edu/funfacts/random/

I clicked on the random link and got this: http://www.math.hmc.edu/funfacts/ffiles/10001.2-3-8.shtml

(Bike with square wheels)

fuck yeh, cheers, that saved me a load of time!

my rate is approx £65/hour.

my rate is approximately £6.50 an hour, I spent a year working with matlab too. :(

Tommy, answer my question! Saw your photo in the names to faces thread, and you look a lot like an old teacher of mine.

tbh it took 2 minutes of this
[URL="http://lmgtfy.com/?q=matlab+topographic+map"][/URL]

Tommy, answer my question! Saw your photo in the names to faces thread, and you look a lot like an old teacher of mine.

Sorry no. I missed out on the cushy opportunity to teach there. A friend of mine did, a 6' 7" Welsh man.

yeh but it's the "topographical" bit of that which is key. I do maths not map names!

Love the thread, wish I could understand a thing you're saying.