Develop a function named
hours->minutes which takes in a number of minutes and
returns the number of seconds in that many minutes.
(We'll probably do this in class.)
Develop a function named
days->hours which takes in a number of days and returns the
number of hours in that many days.
Develop a function named
days->minutes which takes in a number of days and returns the
number of minutes in that many days.
Hint: re-use previously-written functions. You should
be able to write this function with no numbers in the definition
(although you'll need numbers in your examples, of course).
Develop a function named
dhm->minutes which takes in three numbers: how
many days, how many hours, and how many minutes, in that order, and
returns the total number of minutes.
Hint: re-use previously-written functions. You should
be able to write this, too, with no numbers in the definition.
Develop a function named f->c which
takes in a temperature in degrees Fahrenheit and returns the same
temperature expressed in degrees Celsius. (The formula is C =
(F-32)*5/9; we'll probably do this in class.)
Develop a function named c->k which
takes in a temperature in Celsius and returns the corresponding number of
degrees Kelvin. (A Kelvin degree is the same size as a Celsius degree, but
Kelvin's 0 is the same as -273 Celsius, so 0 Celsius is 273
Kelvin.)
Develop a function named f->k which
takes in a temperature in Fahrenheit and returns the corresponding number of
degrees Kelvin. (For example, 32 degrees Fahrenheit is the same as
273 degrees Kelvin.)
Hint: re-use previously-written functions, so you can
do it with no numbers in the definition.
You've just learned that 0 Kelvin is, more accurately, -273.15
Celsius. Make whatever modifications are necessary to
accommodate this more-accurate conversion in both c->k and
f->k.
Develop a function named convert-3-digits
which
takes in three numbers (the hundreds, tens, and ones places of a 3-digit
number, in that order) and returns the 3-digit number. For example,
(convert-3-digits 4 2 5)
should return the number 425. Note that Scheme doesn't have an
operation for "put this number next to that one"; you have to use
arithmetic operations like +, -, *, /.
Next, develop a function named
convert-3-reversed which takes in the ones, tens, and
hundreds places of a 3-digit number, in that order, and returns the
3-digit number. For example,
(convert-3-reversed 5 7 2)
should return the number 275. Hint: re-use an old
function!
Do (but don't turn in) all the exercises from section 2.4 of the textbook (the ones about errors).
Develop a function can-vote? which takes
in a person's age and returns a Boolean indicating whether that person
is old enough to vote.
Develop a function can-vote-but-not-drink?
which takes in a person's age and returns a Boolean indicating whether
that person is old enough to vote, but too young to drink alcohol.
Download and install the "tiles-world" teachpack:
- In DrScheme, choose "File->Install .plt file..." and type in the URL "http://home.adelphi.edu/sbloch/class/160/tiles-world.plt", without the quotation marks. It should show you a bunch of messages ending with "Done setting up". You should have to do this only once on a given computer.
- Then choose "Language->Add Teachpack..." and select "tiles-world.ss". This may need to be done again every time you run DrScheme.
- Read the documentation on this teachpack.
Develop a function blot which
takes in an image and a string (a color, e.g. "blue",
"red", etc.) and returns the same image with the center
covered by an oval of the specified color.
Develop a function that does something fun with images,
using some combination of image-above,
image-beside, reflect-vert,
reflect-horiz, rotate-cw,
rotate-ccw, and rotate-180.