Python code conversion to processing Java

Processing Coding Questions
7

Let me try to clarify it for you. lambda is a shorter way of writing functions, and all of the following are equivalent ways of writing it. For example,

f = lambda x: 2*x

is similar to python’s def:

def f(x):
    return 2*x

which is similar to java’s way of defining functions:

float f(float x) {
  return 2*x;
}

So, the function lambda that you got here:

lambda (r,g,b): step(r,g,b,8)

is similar to:

def f(tuple):
    return step(tuple[0],tuple[1],tuple[2],8)

Sort is a list method that usually modifies a list so that its elements are in increasing order, like from lowest to highest, or from A to Z. For instance, in python, if you tried to sort the following list:

names = ["Stephanie","Sarah","Abe","Al"]
names.sort()

you would get them back in alphabetical order:

['Abe', 'Al', 'Sarah', 'Stephanie']

But what if you wanted to sort them by their age instead? Let’s assume you have the following:

    names = ["Stephanie","Sarah","Abe","Al"]
    age = {"Stephanie":26,
           "Sarah":28,
           "Abe":25,
           "Al":24}

Then I would want to sort the names based on their ages, which you can do by setting the key argument as follows:

    names = ["Stephanie","Sarah","Abe","Al"]
    age = {"Stephanie":26,
           "Sarah":28,
           "Abe":25,
           "Al":24}
    names.sort(key=lambda x: age[x])
    print(names)

which returns:

['Al', 'Abe', 'Stephanie', 'Sarah']

key argument kind of maps a function to each element in the list. In this case, I used a lambda function because I needed it for a simple purpose.

Going back to the original topic to translating it to Java, you essentially need to sort a list of tuples of (R,G,B) colors based on the order you would get if you had sorted a list of those same colors after performing step() function on the elements of that list. I’m sure gotoloop has suggestions on how to do that in java.

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