#+STARTUP: showall

#+TITLE:     Class 13: python and control structures
#+AUTHOR:    Kurt Schwehr
#+EMAIL:     schwehr@ccom.unh.edu
#+DATE:      <2011-10-13 Thu>
#+DESCRIPTION: Marine Research Data Manipulation and Practices
#+KEYWORDS: ipython matplotlib
#+LANGUAGE:  en
#+OPTIONS:   H:3 num:nil toc:t \n:nil @:t ::t |:t ^:t -:t f:t *:t <:t
#+OPTIONS:   TeX:t LaTeX:nil skip:t d:nil todo:t pri:nil tags:not-in-toc
#+INFOJS_OPT: view:nil toc:nil ltoc:t mouse:underline buttons:0 path:http://orgmode.org/org-info.js
#+LINK_HOME: http://vislab-ccom.unh.edu/~schwehr/Classes/2011/esci895-researchtools/


* Introduction

* Using =if=                                                             :if:

#+BEGIN_SRC python
if True:
    print 'yes'
#+END_SRC

#+BEGIN_SRC python
if False:
    print 'yes'
#+END_SRC

** =else=

#+BEGIN_SRC python
if True:
    print 'yes'
else:
    print 'no'
#+END_SRC

#+BEGIN_SRC python
if False:
    print 'yes'
else:
    print 'no'
#+END_SRC

** A special one line =if=

#+BEGIN_SRC python
'equal' if 1==0 else 'really not-equal'
#+END_SRC

#+BEGIN_SRC python
print 'equal' if 1==0 else 'really not-equal'
#+END_SRC

#+BEGIN_SRC python
answer = 'equal' if 1==0 else 'really not-equal'
#+END_SRC

* While loops

#+BEGIN_SRC python
  count = 0
  while count < 10:
      print count
      count += 2
#+END_SRC

* Making a function                                                :function:

You will want to break you problem down into sections. One way to do
that is to write functions.

#+BEGIN_SRC python
def hello():
    print 'hello world function'

# Call it
hello()
#+END_SRC


#+BEGIN_SRC python
def add_one(number):
    new_number = number + 1
    return new_number

# Calling our function.  Pass in the number 9
add_one(9)
#+END_SRC

* classes

containers that work together

#+BEGIN_SRC python
import math

class Circle(object):
    def __init__(self, radius):
        self.radius = radius

    def get_area(self):
        return 2 * math.pi * self.radius

    def __str__(self):
        return 'Circle of radius ' + str(self.radius)
        
a_circle = Circle(10.2)
print 'area is:', a_circle.get_area()
print str(a_circle)
#+END_SRC

* modules

composed of

- variables
- functions
- classes

* Getting data!                                                       :socat:

#+BEGIN_SRC sh
sudo apt-get install socat
#+END_SRC

#+BEGIN_SRC sh
socat TCP4:datalogger1.ccom.nh:36000 - | head
#+END_SRC

#+BEGIN_EXAMPLE 
socat TCP4:datalogger1.ccom.nh:36000 - | head
$WIMDA,30.0261,I,1.0168,B,13.0,C,,,,,,,14.1,T,29.5,M,1.8,N,0.9,M*2A,rccom-airmar,1318512281.75
$WIMWD,14.9,T,30.3,M,1.8,N,0.9,M*56,rccom-airmar,1318512281.83
$HCHDT,26.0,T*1D,rccom-airmar,1318512281.87
$WIMWV,348.9,T,1.8,N,A*2A,rccom-airmar,1318512281.92
$WIMWV,347.2,R,1.9,N,A*29,rccom-airmar,1318512281.98
$HCHDT,26.0,T*1D,rccom-airmar,1318512282.27
$GPVTG,339.3,T,354.7,M,0.1,N,0.2,K,D*2A,rccom-airmar,1318512282.35
$GPZDA,132442,13,10,2011,00,00*4B,rccom-airmar,1318512282.42
$WIMWV,347.8,R,1.9,N,A*23,rccom-airmar,1318512282.48
$GPGGA,132442,4308.1264,N,07056.3757,W,2,9,0.9,35.8,M,,,,*00,rccom-airmar,1318512282.6
2011/10/13 09:24:42 socat[82807] E write(1, 0x802e00, 95): Broken pipe
#+END_EXAMPLE

http://gpsd.berlios.de/NMEA.html

Save a bunch to a file:

#+BEGIN_SRC sh
socat TCP4:datalogger1.ccom.nh:36000 - | head -1000 > ccom-weather.log
#+END_SRC