; CS101, Spring 2013
; HW 2

(display "\n         CS101 Assignment 2, Spring 2013")
(display "\n         PLEASE WRITE YOUR NAME HERE\n\n")

; Before starting to write functions, you should read completely through
; every problem statement. There are three parts to problem 1 and one 
; part for problem 2.


(display "Problem 1(a): Writing a function to convert days to hours\n")
; 
;     Define a Racket procedure that consumes a single input representing 
;     a number of days, and returns as its output the corresponding number 
;     of hours.  Call the function days->hours.
;     
;     Examples of running the days->hours function are shown below:
;     
;     (days->hours 1)   ==> 24
;     (days->hours 2)   ==> 48
;     (days->hours 4)   ==> 96
;     
;     Use the constant HOURS-PER-DAY (defined below) in your function 
;     instead of the literal value 24.
;     

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;Constant definition:
(define HOURS-PER-DAY 24)

;Contract:
;Header:
;Purpose:   

;; Pre-function tests:

              
;; Function definition:




;; Post-function printf's (uncomment when ready):
;(printf "(days->hours 1) => ~a~%~%" (days->hours 1))
;(printf "(days->hours 2) => ~a~%~%" (days->hours 2))
;(printf "(days->hours 4) => ~a~%~%" (days->hours 4))



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(display "Problem 1(b): Defining a function to convert hours to minutes\n")
;     
;     Use a define special form to name a similar procedure, 
;     called hours->minutes, that takes as input a number of hours and   
;     returns as output the corresponding number of minutes.
;     
;     Examples of running the hours->minutes function are shown below:
;     
;     (hours->minutes 1)   ==> 60
;     (hours->minutes 1.5) ==> 90
;     (hours->minutes 4)   ==> 240
;     
;     To avoid using literal values in your procedure, define a 
;     constant for the number of minutes in an hour.          
;     

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;; CONSTANT DEFINITION:


;Contract:
;Header:
;Purpose:   

;; Pre-function tests:

              
;; Function definition:



;; Post-function printf's (uncomment when ready):
;(printf "(hours->minutes 1) => ~a~%" (hours->minutes 1))
;(printf "(hours->minutes 1.5) => ~a~%" (hours->minutes 1.5))
;(printf "(hours->minutes 4) => ~a~%" (hours->minutes 4))



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(display "Problem 1(c): Defining a composite function\n")
; 
;     Finally, use a define special form to name a similar procedure, 
;     called days->minutes, that takes as its input a number of days 
;     and returns as output the corresponding number of minutes.  The 
;     body of the lambda expression in the days->minutes function should 
;     COMPOSE the two functions days->hours and hours->minutes analogous 
;     to the way that the mathematical expression f(g(x)) composes the
;     functions f and g. In other words, days->minutes should use 
;     days->hours and hours->minutes as helper functions.  
;     
;     Examples of running the days->minutes function are shown below:
;     
;     (days->minutes 1)   ==> 1440
;     (days->minutes 0.1) ==> 144.0
;     (days->minutes 0)   ==> 0
;     

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;Contract:
;Header:
;Purpose:   

;; Pre-function tests:

      

;; Function definition:




;Post-function printf's (uncomment when ready):
;(printf "(days->minutes 1) => ~a~%" (days->minutes 1))
;(printf "(days->minutes 0.1) => ~a~%" (days->minutes 0.1))
;(printf "(days->minutes 0) => ~a~%" (days->minutes 0))
;(printf "(days->minutes 5) => ~a~%" (days->minutes 5))


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(display "Problem 2: Define a panic thermometer\n")
; 
;  Using a primitive function called TEXT to express urgency.
;  
;  To read about how to use the text function, go to the help menu and the 
;  help desk, type in the function name text at the top of the page, and 
;  read the function contract.
;  
;  Take note that the first argument of the text function is a string, but
;  you are given a number to output.  The function to convert a number to
;  a string is called number->string.  To make sure a number like 98.6 is
;  produced in decimal form (not as a fraction), use the function 
;  exact->inexact.
;  
;                -----------------------------------
; 
;  Develop a function called panic-thermometer that takes in an integer
;  (in degrees Fahrenheit) and produces an image of the temperature as 
;  text, colored either blue (below 99 degrees F), gold (at least 99
;  but less than 101 degrees F), orange (at least 101 but less than 104
;  degrees F), or red (104 degrees F or higher).
;                               
;  Besides the coloring of the image, the function should also make the
;  size of the output image larger if the temperature is higher.  For text 
;  shown in blue, the size of the text should be 24 point. For gold text, 
;  the size of the text should be 28 point. For orange text, the size of 
;  the text should be 32 point. For red text, the size should be 48 point.  
;  
;  You should define sufficient constants so that you use no literal
;  values (numbers or strings) inside the procedure you write.  This will
;  mean you should write 11 constant definitions. To be specific, you
;  should have:
;            3 constant names for body temperature in degrees F
;            4 constant names for color strings
;            4 constant names for font size 
;  
;  It may help you to write the function first using literal values in
;  the code and then replace the literal values with the constant names 
;  after you know where the constant names should be placed in the 
;  function. Be sure to type the constant names in the function and in
;  the check-expect statements before you submit this homework assignment. 
;                               


(newline)
;; Constant definitions:


;Contract: 
;Header:   
;Purpose:  To express a person's body temperature with an image that is in a 
;          larger font and closer to the red end of the visual spectrum as the 
;          temperature gets higher.
;
;Pre-function tests: (be sure to test all branches of the function)
;To write the function tests, compare the result of calling the function on 
;the call to the text function that is run for a particular temperature. 





;Function definition:






;Post-function printf's: (uncomment when ready)  
;(printf "(panic-thermometer 98.6) => ~a~%" (panic-thermometer 98.6))
;(printf "(panic-thermometer 100) => ~a~%" (panic-thermometer 100))
;(printf "(panic-thermometer 102) => ~a~%" (panic-thermometer 102))
;(printf "(panic-thermometer 104) => ~a~%" (panic-thermometer 104))