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POPython: implement a script in a function. Some suggestions
 

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  1. POPython: implement a script in a function. Some suggestions
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    <p>first of all, i am quite new in Python (an programming area) but i wish to learn and convert a function developed by <a href="https://stackoverflow.com/users/837847/jwpat7">jwpat7</a>. Given a set of points derived from a convex hull</p> <pre><code>hull= [(560023.44957588764,6362057.3904932579), (560023.44957588764,6362060.3904932579), (560024.44957588764,6362063.3904932579), (560026.94957588764,6362068.3904932579), (560028.44957588764,6362069.8904932579), (560034.94957588764,6362071.8904932579), (560036.44957588764,6362071.8904932579), (560037.44957588764,6362070.3904932579), (560037.44957588764,6362064.8904932579), (560036.44957588764,6362063.3904932579), (560034.94957588764,6362061.3904932579), (560026.94957588764,6362057.8904932579), (560025.44957588764,6362057.3904932579), (560023.44957588764,6362057.3904932579)] </code></pre> <p>this script return a print of all possible area following this <a href="https://stackoverflow.com/questions/13542855/python-help-to-implement-an-algorithm-to-find-the-minimum-area-rectangle-for-gi">post problem</a>. The code develop by jwpat7 is: </p> <pre><code>import math def mostfar(j, n, s, c, mx, my): # advance j to extreme point xn, yn = hull[j][0], hull[j][1] rx, ry = xn*c - yn*s, xn*s + yn*c best = mx*rx + my*ry while True: x, y = rx, ry xn, yn = hull[(j+1)%n][0], hull[(j+1)%n][1] rx, ry = xn*c - yn*s, xn*s + yn*c if mx*rx + my*ry &gt;= best: j = (j+1)%n best = mx*rx + my*ry else: return (x, y, j) n = len(hull) iL = iR = iP = 1 # indexes left, right, opposite pi = 4*math.atan(1) for i in range(n-1): dx = hull[i+1][0] - hull[i][0] dy = hull[i+1][1] - hull[i][1] theta = pi-math.atan2(dy, dx) s, c = math.sin(theta), math.cos(theta) yC = hull[i][0]*s + hull[i][1]*c xP, yP, iP = mostfar(iP, n, s, c, 0, 1) if i==0: iR = iP xR, yR, iR = mostfar(iR, n, s, c, 1, 0) xL, yL, iL = mostfar(iL, n, s, c, -1, 0) area = (yP-yC)*(xR-xL) print ' {:2d} {:2d} {:2d} {:2d} {:9.3f}'.format(i, iL, iP, iR, area) </code></pre> <p>the result is:</p> <pre><code>i iL iP iR Area 0 6 8 0 203.000 1 6 8 0 211.875 2 6 8 0 205.800 3 6 10 0 206.250 4 7 12 0 190.362 5 8 0 1 203.000 6 10 0 4 201.385 7 0 1 6 203.000 8 0 3 6 205.827 9 0 3 6 205.640 10 0 4 7 187.451 11 0 4 7 189.750 12 1 6 8 203.000 </code></pre> <p>i wish to create a single function with the return of Length, Width, and Area of the smallest rectangle. Ex:</p> <pre><code>Length, Width, Area = get_minimum_area_rectangle(hull) print Length, Width, Area 18.036, 10.392, 187.451 </code></pre> <p>my questions are:</p> <ol> <li>do i need to create a single function or two function. ex: def mostfar and get_minimum_area_rectangle</li> <li>hull is a list of value. Is it the best format? <ol start="3"> <li>followint the one function approach, i have a problem to integrate mostfar inside </li> </ol></li> </ol> <p>Thanks in advance</p> <p>1) solution: one function following the first solution suggest by Scott Hunter, i have a problem to integrate mostfar() inside get_minimum_area_rectangle(). Any suggestion or help are really appreciate because i can learn. </p> <pre><code>#!/usr/bin/python import math def get_minimum_area_rectangle(hull): # get pi greek pi = 4*math.atan(1) # number of points n = len(hull) # indexes left, right, opposite iL = iR = iP = 1 # work clockwise direction for i in range(n-1): # distance on x axis dx = hull[i+1][0] - hull[i][0] # distance on y axis dy = hull[i+1][1] - hull[i][1] # get orientation angle of the edge theta = pi-math.atan2(dy, dx) s, c = math.sin(theta), math.cos(theta) yC = hull[i][0]*s + hull[i][1]*c </code></pre> <p>from here following the above example of jwpat7 i need to use mostfar(). I have a problem to understand how integrate (sorry for the not right term) mostfar in this point</p>
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    1. COTo answer your question about the solution you chose: Just indent the `def mostfar:...` code and put it inside of the `def get_minimum_area_rectangle:` at the beginning.
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      1. POPython: implement a script in a function. Some suggestions
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    2. CO@martineau, thanks. But do you think is elegant put def mostfar inside def get_minimum_area_rectangle? do you know some elegant way do solve this? thanks again
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    3. COIt's only slightly inelegant, especially since it's truly a local function. It's slightly _inefficient_ in the sense that the function definition is executed every time the outer function is called. Doing so avoids that and it would be considered a private module function that way if you added an underscore prefix to its name. Another way to achieve this would be to put it into a class as a `_mostfar()` method. `get_minimum_area_rectangle` could then be a separate method which calls it or renamed the `__call__()` method of the class (making it a "functor", or function-object class).
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      1. POPython: implement a script in a function. Some suggestions
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