Things are challenge

To learn the computer science, the logic thinking is the most important thing we should care about. Once you have a clear logic, you could understand the codes much easier. I believe my logic thinking is not bad. I can understand most of the code very fast, but there are still some thing really confuse me. The first thing is the code "map-image" I could not understand how they use this code to achieve "number-->image" and another one I know how to use but could not understand well is "list-color". I am confusing how they connect the number to the color that well.

Two Projects

I will be  really happy if the professor could give us the solutions of the two projects before the final exam. I still did't get some of the question of the two project. I know how to do most of them, but can not make the program run perfectly. I hope we can get the solutions so that I could understand why I was wrong.

History and Code

For the whole course I think the history of computer is really hard.  The reading material are kind of messy.  For the two term tests, even though I read all of the material,  There were still a lot of questions I didn't know how to answer. I hope we can get a clear structure about what we learned, that will help me prepare the final exam  well
       
 The code that we learned is not that hard, but the textbook could not give a clear explain of all of them. And some of code have a circle structure. I do know how to solve them, but I think there must have a way to solve them faster then that.   

Project 1

Not as hard as I thought， but there still two things confuse me a lot

1 what is the code "map-image" really means?

2 for the check-key part,

(check-expect (check-key (make-clocktime 1 2 3 GO) "up") (make-clocktime 1 2 3 GO))
(check-expect (check-key (make-clocktime 1 2 3 GO) "down") (make-clocktime 1 2 3 STOP))


(define (check-key im k)
  (cond
    [(equal? k "down") STOP]
    [else im]))

I just cannot find a definition which could fit the two check-expect well
I think the reason is the make-clocktime and the GO sigh are bound together, represented by im. So I don't know how to change only one part of the whole item.
And I tried to define another function to help me solve this problem another way, but all the "placeholder" I tried to use was showed "not defined"...

Anyway, doing the project is a great way for me to prepare the term test  next week.  

textbook is not that clear...

I think the textbook only give us a basic idea of deferent functions, but the exercise is much harder then what I learned from examples...
Also the textbook put the codes, definitions and some statements all together makes me really confuse about how the code working.
I believe if we can have more examples that will help us understand the code better.