Midterm Exam 1 Review Fall 2003: Generalized changeColor
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Answers? Comments? Comments on answers?
Something along these lines? I haven't actually tried it but I think it should work.
def changeColor(pict,amount,colorcode):
for p in getPixels(pict):
if colorcode=1:
setRed(p,getRed(p)*(amount+1))
if colorcode=2:
setGreen(p,getGreen(p)*(amount+1))
if colorcode=3:
setBlue(p,getBlue(p)*(amount+1))
- I tried the program - it has to be == not just =
| That's right. JES only accepts == when testing a value. Lauren Biddle |
You could enter a value outside the range given (-.99 to .99) and the program would work fine.
| Is that program good style? I dont think so, there must be a more readable way to write it. Can anyone tell me what it is? Larry Olson |
Should you change (amount + 1) to some other variable which is defined earlier? Or did you mean something else?
is it ok to do
(px, getRed*(1+#))
...or does it have to be (px, getRed(px)*(1+#))
| I don't know what that first one means. getRed takes a pixel as input. It only works with the input pixel. Mark Guzdial |
def changeColor(picture,amount,colorcode):
for p in getPixels(picture):
if (amount >= -.99)or (amount <= .99):
if colorcode == 1
setRed(p,getRed(p)*(amount+1)
if colorcode == 2:
setBlue(p,getBlue(p)*(amount+1)
if colorcode == 3:
setGreen(p,getGreen(p)(amount+1)
I can't think of a more readable way to write this...
| The first if statement will allow any amount in since you are using an or operand. Haile Seifu |
does it matter that you left out a on line 9?
or should it read
setGreen(p,getGreen(p)*(amount+1)
Do we need to worry about the constraints on this problem? I saw a post on the second problem (Generalized image filter) that said not to worry about the constraints.
i think you forgot your ending par. on lines 5, 7 and 9...
def changeColor(picture, amount, colorcode):
for p in getPixels(picture):
if (-.99<=amount<=.99):
if colorcode == 1:
setRed(p,getRed(p)*(amount+1))
if colorcode == 2:
setBlue(p,getBlue(p)*(amount+1))
if colorcode == 3:
setGreen(p,getGreen(p)(amount+1))
this worked when i ran (file, .5, 2) and didn't work when I ran (file, 2.0, 2) so hopefully its right!
| This is good code, but do you really need the first if statement? It sounds to me from the problem that you don't since you are guaranteed to have a value between .99 and -.99 already. Also, couldn't you use "elif" to make your program run faster? Lauren Biddle |
hm..messed up my spacing and messed up (.-99 = amount = .99)
well however you get the less than sign in there...
use <
i thought i needed the first if statement, because the first example of code on the page is just what i have without that if statement and they said that it would work fine for a number outside of that range. So how would it not work for a number out of the range?
So do you need to include the if statement with the constraints for this and the generalized image filter or not.It works fine without it.
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