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Re: distance from Easter Island to Chile
From: |
Emanuel Berg |
Subject: |
Re: distance from Easter Island to Chile |
Date: |
Wed, 23 Apr 2014 04:49:04 +0200 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) |
Made this into a CLI tool that fetches data (with curl)
from Wikipedia.
Even if you don't care for the CLI, the Emacs code is
improved, too.
It is sort of *slow* because of the fetch, and the
start of Emacs, but perhaps the parsing is
heavy-handed, as well.
Try:
distance 'Easter Island' 'Santiago de Chile'
distance Peking Paris
# etc.
Pretty cool, huh?
I put all the files here:
http://user.it.uu.se/~embe8573/distance/
1) loc
#!/bin/zsh
args=$(echo $* | sed 's/ /%20/g')
url=https://en.wikipedia.org/w/index.php\?title=$args\&printable=yes
coords=$(curl -s $url | grep -o '"geo">[-.[:digit:]]*; [-.[:digit:]]*<' | head
-n 1 | sed 's/\("geo">\|-\|;\|<\)//g')
2) distance
#!/bin/zsh
coords1=`loc $1`
coords2=`loc $2`
lat1=$(echo $coords1 | cut -d" " -f1)
long1=$(echo $coords1 | cut -d" " -f2)
lat2=$(echo $coords2 | cut -d" " -f1)
long2=$(echo $coords2 | cut -d" " -f2)
emacs -Q -script distance.el $1 $lat1 $long1 $2 $lat2 $long2
3) distance.el
(require 'cl)
(defun sin2 (p)
(let ((sin-p (sin p)))
(* sin-p sin-p) ))
(defun haversine (a b)
(sin2 (/ (- a b) 2) ))
(setq earth-radius 6367.4447)
(defun distance (p1 p2)
(let ((from (car p1))
(to (car p2))
(lat1 (degrees-to-radians (caadr p1)))
(long1 (degrees-to-radians (cadadr p1)))
(lat2 (degrees-to-radians (caadr p2)))
(long2 (degrees-to-radians (cadadr p2))) )
(message "%s -> %s: %.2f km" from to
(* 2 earth-radius
(asin
(sqrt
(+ (haversine lat2 lat1)
(* (cos lat2)
(cos lat1)
(haversine long2 long1) ))))))))
(let ((from (elt argv 0))
(lat1 (string-to-number (elt argv 1)))
(long1 (string-to-number (elt argv 2)))
(to (elt argv 3))
(lat2 (string-to-number (elt argv 4)))
(long2 (string-to-number (elt argv 5))) )
(distance (list from (list lat1 long1))
(list to (list lat2 long2)) ))
--
underground experts united:
http://user.it.uu.se/~embe8573
- distance from Easter Island to Chile, Emanuel Berg, 2014/04/19
- Re: distance from Easter Island to Chile, Frank Stutzman, 2014/04/20
- Re: distance from Easter Island to Chile, Emanuel Berg, 2014/04/20
- Re: distance from Easter Island to Chile, giacomo . boffi, 2014/04/20
- Message not available
- Re: distance from Easter Island to Chile, Emanuel Berg, 2014/04/20
- Re: distance from Easter Island to Chile, Emanuel Berg, 2014/04/20
- Re: distance from Easter Island to Chile, giacomo . boffi, 2014/04/21
- Message not available
- Re: distance from Easter Island to Chile, Emanuel Berg, 2014/04/21
- Re: distance from Easter Island to Chile, Emanuel Berg, 2014/04/21
- Re: distance from Easter Island to Chile,
Emanuel Berg <=
- Message not available
- Re: distance from Easter Island to Chile, Emanuel Berg, 2014/04/20
Re: distance from Easter Island to Chile, Barry Margolin, 2014/04/20
Re: distance from Easter Island to Chile, Eli Zaretskii, 2014/04/20
Message not available
Re: distance from Easter Island to Chile, Emanuel Berg, 2014/04/20
Re: distance from Easter Island to Chile, Emanuel Berg, 2014/04/21