Sunday, July 26, 2009
Getting bored one fine weekend, I decided to start learning Ruby, a scripting language. My impressions of Ruby thus far have all been positive - it is much more fun to code in than C or Actionscript. Here is a simple example program I just coded learning Ruby, and while it might not be of the highest quality I hope it'll be of some help to someone out there.
#Heat Index Calculator in Celsius
#Formula from Wikipedia (http://en.wikipedia.org/wiki/Heat_index)
#Formula for approximating the heat index in degrees Fahrenheit is accurate to within ±1.3 °F.
#It is useful only when the temperature is at least 80 °F (26.6°C) and the relative humidity is at least 40%.
puts 'Temperature(C) (space) relative humidity(%)'
#Clears the buffer in prepration for input
STDOUT.flush
#Gets input, removes spaces '.split(/ /)' and then converts each element to a float 'map{|x| x.to_f}' - x being the elements and 'x.to_f' the operation to carry out on each element
tc,r = gets.split(/ /).map {|x| x.to_f}
#°C to °F Multiply by 9, divide by 5, then add 32
tf = tc * 9 / 5 + 32
#Constants used
C1 = -42.379
C2 = 2.04901523
C3 = 10.14333127
C4 = -0.22475541
C5 = -6.83783 * 10**-3
C6 = -5.481717 * 10**-2
C7 = 1.22874 * 10**-3
C8 = 8.5282 * 10**-4
C9 = -1.99 * 10**-6
#Applying the heat index formula
hif = C1 + C2 * tf + C3 * r + C4 * tf * r + C5 * tf**2 + C6 * r**2 + C7 * tf**2 * r + C8 * tf * r**2 + C9 * tf**2 * r**2
#°F to °C
hic = (hif - 32) * 5 / 9
#Displays heat index to 5 significant figures, converts it into a string so that 'C' can be appended
puts hic.to_s[0..4] + ' C'
Labels: code, heat index, programming, ruby, SINGAPORE IS HOT
Friday, July 17, 2009
My teachers would have commented on how bad my handwriting is. Piss off, scores of teachers! It's not ugly, it's beautiful.