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I am reforming the 2D coordinate number in a aligned way which was not aligned (coordinate numbers were suffled) before.
I have below input coordinates,
X = [2, 2, 3, 4, 4, 4, 4, 5, 6, 6, 6, 6, 6, 5, 4, 3, 5, 5, 5]
Y = [2, 3, 3, 3, 4, 5, 6, 6, 6, 5, 4, 3, 2, 2, 2, 2, 3, 4, 5]
I have to make it aligned. Therefore, I first applied Sorted function on this coordinates. I got below output after it.
merged_list1 = sorted(zip(X, Y))
output
X1_coordinate_reformed = [2, 2, 3, 3, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6]
Y1_coordinate_reformed = [2, 3, 2, 3, 2, 3, 4, 5, 6, 2, 3, 4, 5, 6, 2, 3, 4, 5, 6]
Still it iot aligned properly. I want two consecutive nodes place next to each other. Therefore I am applying the approach to find the nearest coordinate from origin to find the very first node. Then from the first node, I found another nearest coordinate and so on...For that, I have applied below code,
First I wrote a function which calculates the distance and gives index of the nearest coordinate from the list.
def solve(pts, pt):
x, y = pt
idx = -1
smallest = float("inf")
for p in pts:
if p[0] == x or p[1] == y:
dist = abs(x - p[0]) + abs(y - p[1])
if dist < smallest:
idx = pts.index(p)
smallest = dist
elif dist == smallest:
if pts.index(p) < idx:
idx = pts.index(p)
smallest = dist
return idx
coor2 = list(zip(X1_coordinate_reformed, Y1_coordinate_reformed)) # make a list which contains tuples of X and Y coordinates
pts2 = coor2.copy()
origin1 = (0, 0)
new_coor1 = []
for i in range(len(pts2)):
pt = origin1
index_num1 = solve(pts2, pt)
print('index is', index_num1)
origin1 = pts2[index_num1]
new_coor1.append(pts2[index_num1])
del pts2[index_num1]
After running the code, I got below output,
[(6, 6), (5, 6), (4, 6), (4, 5), (4, 4), (4, 3), (3, 3), (2, 3), (2, 2), (3, 2), (4, 2), (5, 2), (5, 3), (5, 4), (5, 5), (6, 5), (6, 4), (6, 3), (6, 2)]
Which is not correct because it can be clearly understand that,
coor2 = [(2, 2), (2, 3), (3, 2), (3, 3), (4, 2), (4, 3), (4, 4), (4, 5), (4, 6), (5, 2), (5, 3), (5, 4), (5, 5), (5, 6), (6, 2), (6, 3), (6, 4), (6, 5), (6, 6)]
origin = (0, 0)
if we find the distance between Origin which was (0, 0) in very first and from every coordinate from above coor2 list, we will get (2,2) is nearest coordinate. Then How come my code gives (6,6) is the nearest coordinate??
The interesting thing is, if I apply the same procedure (sorting followed by finding nearest coordinate) on below coordinates,
X2_coordinate = [2, 4, 4, 2, 3, 2, 4, 3, 1, 3, 4, 3, 1, 2, 0, 3, 4, 2, 0]
Y2_coordinate = [3, 4, 2, 1, 3, 2, 1, 0, 0, 2, 3, 4, 1, 4, 0, 1, 0, 0, 1]
After applying sorted function
X2_coordinate_reformed = [0, 0, 1, 1, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4]
Y2_coordinate_reformed = [0, 1, 0, 1, 0, 1, 2, 3, 4, 0, 1, 2, 3, 4, 0, 1, 2, 3, 4]
After applying method of searching nearest coordinates mentioned above, the result I got
[(0, 0), (0, 1), (1, 1), (1, 0), (2, 0), (2, 1), (2, 2), (2, 3), (2, 4), (3, 4), (3, 3), (3, 2), (3, 1), (3, 0), (4, 0), (4, 1), (4, 2), (4, 3), (4, 4)]
Kindly suggest me where I am doing wrong and what should I change??
It is better to use scipy for finding closest coordinate.
The code given below works.
from scipy import spatial
pts = merged_list1.copy()
origin = (0, 0)
origin = np.array(origin)
new_coordi = []
for i in range(len(pts)):
x = origin
distance,index = spatial.KDTree(pts).query(x)
new_coordi.append(pts[index])
origin = np.array(pts[index])
del pts[index]
For Python 3.9 and numpy 1.21.5, I have four 4-D numpy arrays:
x = np.random.normal(loc=0.0, scale=1.0, size=(5, 5, 7, 10))
y = np.random.normal(loc=0.0, scale=1.0, size=(5, 5, 7, 10))
z = np.random.normal(loc=0.0, scale=1.0, size=(5, 5, 7, 10))
w = np.random.normal(loc=0.0, scale=1.0, size=(5, 5, 7, 10))
x.shape, y.shape, z.shape, w.shape
# ((5, 5, 7, 10), (5, 5, 7, 10), (5, 5, 7, 10), (5, 5, 7, 10))
I want to stack them to get the desired shape: (4, 5, 5, 7, 10).
The code that I have tried so far includes:
np.vstack((x, y, z, w)).shape
# (20, 5, 7, 10)
np.concatenate((x, y, z, w), axis=0).shape
# (20, 5, 7, 10)
np.concatenate((x, y, z, w)).shape
# (20, 5, 7, 10)
They seem to be doing (4 * 5, 5, 7, 10) instead of the desired shape/dimension: (4, 5, 5, 7, 10)
Help?
The following code can get the expected shape:
np.array([x, y, z, w]) # shape --> (4, 5, 5, 7, 10)
I am currently self-learning python for a career change. While doing some exercises about 'list', I encountered IndexError: list index out of range.
So, I am trying to build a function, that determines which product should be placed on my store's shelves. But, I also put constraints.
The shelve has a max capacity of 200
small-sized items should be placed first
if two or more items have the same size, the item with the highest price should be placed first
As an input for the function, I have a list of tuples "dairy_items", denoted as [(id, size, price)].
This is my code:
capacity=200
dairy_items=[('p1', 10, 3), ('p2', 13, 5),
('p3', 15, 2), ('p4', 26, 2),
('p5', 18, 6), ('p6', 25, 3),
('p7', 20, 4), ('p8', 10, 5),
('p9', 15, 4), ('p10', 12, 7),
('p11', 19, 3), ('p12', 27, 6),
('p13', 16, 4), ('p14', 23, 5),
('p15', 14, 2), ('p16', 23, 5),
('p17', 12, 7), ('p18', 11, 3),
('p19', 16, 5), ('p20', 11, 4)]
def shelving(dairy_items):
#first: sort the list of tuples based on size: low-to-big
items = sorted(dairy_items, key=lambda x: x[1], reverse=False)
#second: iterate the sorted list of tuples.
#agorithm: retrieve the first 2 elements of the sorted list
#then compare those two elements by applying rules/conditions as stated
#the 'winning' element is placed to 'result' and this element is removed from 'items'. Also 'temp' list is resetted
#do again untill shelves cannot be added anymore (capacity full and do not exceeds limit)
result = []
total_price = []
temp_capacity = []
temp = items[:2]
while sum(temp_capacity) < capacity:
#add conditions: (low first) and (if size the same, highest price first)
if (temp[0][1] == temp[1][1]) and (temp[0][2] > temp[1][2]):
temp_capacity.append(temp[0][1])
result.append(temp.pop(0))
items.pop(0)
temp.clear()
temp = items[:2]
total_price.append(temp[0][2])
elif ((temp[0][1] == temp[1][1])) and (temp[0][2] < temp[1][2]):
temp_capacity.append(temp[1][1])
result.append(temp.pop())
items.pop()
temp.clear()
temp = items[:2]
total_price.append(temp[1][2])
else:
temp_capacity.append(temp[0][1])
result.append(temp.pop(0))
items.pop(0)
temp.clear()
temp = items[:2]
total_price.append(temp[0][2])
result = result.append(temp_capacity)
#return a tuple with three elements: ([list of product ID to be placed in order], total occupied capacity of shelves, total prices)
return result
c:\Users\abc\downloads\listexercise.py in <module>
----> 1 print(shelving(dairy_items))
c:\Users\abc\downloads\listexercise.py in shelving(dairy_items)
28 while sum(temp_capacity) < capacity:
29
---> 30 if (temp[0][1] == temp[1][1]) and (temp[0][2] > temp[1][2]):
31 temp_capacity.append(temp[0][1])
32 result.append(temp2.pop(0))
IndexError: list index out of range
EDIT:
This is the expected result:
#Result should be True
print(shelving(dairy_items) == (['p8', 'p1', 'p20', 'p18', 'p10', 'p17', 'p2', 'p15', 'p9', 'p3', 'p19', 'p13', 'p5', 'p11'], 192, 60))
The IndexError occured because, you had tried to append the 2nd element after popping it from temp because, after popping it out, there will be only one element in temp which can indexed with 0.
Also I noticed a few more bugs which could hinder your program from giving the correct output and rectified them.
The following code will work efficiently...
from time import time
start = time()
capacity = 200
dairy_items = [('p1', 10, 3), ('p2', 13, 5),
('p3', 15, 2), ('p4', 26, 2),
('p5', 18, 6), ('p6', 25, 3),
('p7', 20, 4), ('p8', 10, 5),
('p9', 15, 4), ('p10', 12, 7),
('p11', 19, 3), ('p12', 27, 6),
('p13', 16, 4), ('p14', 23, 5),
('p15', 14, 2), ('p16', 23, 5),
('p17', 12, 7), ('p18', 11, 3),
('p19', 16, 5), ('p20', 11, 4)]
def shelving(dairy_items):
items = sorted(dairy_items, key=lambda x: x[1])
result = ([],)
total_price, temp_capacity = 0, 0
while (temp_capacity+items[0][1]) < capacity:
temp = items[:2]
if temp[0][1] == temp[1][1]:
if temp[0][2] > temp[1][2]:
temp_capacity += temp[0][1]
result[0].append(temp[0][0])
total_price += temp[0][2]
items.pop(0)
elif temp[0][2] < temp[1][2]:
temp_capacity += temp[1][1]
result[0].append(temp[1][0])
total_price += temp[1][2]
items.pop(items.index(temp[1]))
else:
temp_capacity += temp[0][1]
result[0].append(temp[0][0])
total_price += temp[0][2]
items.pop(0)
else:
temp_capacity += temp[0][1]
result[0].append(temp[0][0])
total_price += temp[0][2]
items.pop(0)
result += (temp_capacity, total_price)
return result
a = shelving(dairy_items)
end = time()
print(a)
print(f"\nTime Taken : {end-start} secs")
Output:-
(['p8', 'p1', 'p20', 'p18', 'p10', 'p17', 'p2', 'p15', 'p9', 'p3', 'p19', 'p13', 'p5', 'p11'], 192, 60)
Time Taken : 3.123283386230469e-05 secs
Not sure what the question is, but the following information may be relevant:
IndexError occurs when a sequence subscript is out of range. What does this mean? Consider the following code:
l = [1, 2, 3]
a = l[0]
This code does two things:
Define a list of 3 integers called l
Assigns the first element of l to a variable called a
Now, if I were to do the following:
l = [1, 2, 3]
a = l[3]
I would raise an IndexError, as I'm accessing the fouth element of a three element list. Somewhere in your code, you're likely over-indexing your list. This is a good chance to learn about debugging using pdg. Throw a call to breakpoint() in your code and inspect the variables, good luck!
ok, firstly, you should debug your code, if you print temp before adding temp[1][2] to total_price you would see that the last index is what causing the error, the example is here:
capacity=200
dairy_items=[('p1', 10, 3), ('p2', 13, 5),
('p3', 15, 2), ('p4', 26, 2),
('p5', 18, 6), ('p6', 25, 3),
('p7', 20, 4), ('p8', 10, 5),
('p9', 15, 4), ('p10', 12, 7),
('p11', 19, 3), ('p12', 27, 6),
('p13', 16, 4), ('p14', 23, 5),
('p15', 14, 2), ('p16', 23, 5),
('p17', 12, 7), ('p18', 11, 3),
('p19', 16, 5), ('p20', 11, 4)]
def shelving(dairy_items):
#first: sort the list of tuples based on size: low-to-big
items = sorted(dairy_items, key=lambda x: x[1], reverse=False)
#second: iterate the sorted list of tuples.
#agorithm: retrieve the first 2 elements of the sorted list
#then compare those two elements by applying rules/conditions as stated
#the 'winning' element is placed to 'result' and this element is removed from 'items'. Also 'temp' list is resetted
#do again untill shelves cannot be added anymore (capacity full and do not exceeds limit)
result = []
total_price = []
temp_capacity = []
temp = items[:2]
while sum(temp_capacity) < capacity:
#add conditions: (low first) and (if size the same, highest price first)
if (temp[0][1] == temp[1][1]) and (temp[0][2] > temp[1][2]):
temp_capacity.append(temp[0][1])
result.append(temp.pop(0))
items.pop(0)
temp.clear()
temp = items[:2]
total_price.append(temp[0][2])
elif ((temp[0][1] == temp[1][1])) and (temp[0][2] < temp[1][2]):
temp_capacity.append(temp[1][1])
result.append(temp.pop())
items.pop()
temp.clear()
temp = items[:2]
print(temp) # -----------NEW LINE ADDED TO DEBUG YOUR CODE
total_price.append(temp[1][2])
else:
temp_capacity.append(temp[0][1])
result.append(temp.pop(0))
items.pop(0)
temp.clear()
temp = items[:2]
total_price.append(temp[0][2])
result = result.append(temp_capacity)
#return a tuple with three elements: ([list of product ID to be placed in order], total occupied capacity of shelves, total prices)
return result
shelving(dairy_items)
the result i am getting is:
[('p1', 10, 3), ('p8', 10, 5)]
[('p1', 10, 3), ('p8', 10, 5)]
[('p1', 10, 3), ('p8', 10, 5)]
[('p1', 10, 3), ('p8', 10, 5)]
[('p1', 10, 3), ('p8', 10, 5)]
[('p1', 10, 3), ('p8', 10, 5)]
[('p1', 10, 3), ('p8', 10, 5)]
[('p1', 10, 3), ('p8', 10, 5)]
[('p1', 10, 3), ('p8', 10, 5)]
[('p1', 10, 3), ('p8', 10, 5)]
[('p1', 10, 3), ('p8', 10, 5)]
[('p1', 10, 3), ('p8', 10, 5)]
[('p1', 10, 3), ('p8', 10, 5)]
[('p1', 10, 3), ('p8', 10, 5)]
[('p1', 10, 3), ('p8', 10, 5)]
[('p1', 10, 3), ('p8', 10, 5)]
[('p1', 10, 3), ('p8', 10, 5)]
[('p1', 10, 3), ('p8', 10, 5)]
[('p1', 10, 3)]
Traceback (most recent call last):
File "<string>", line 55, in <module>
File "<string>", line 44, in shelving
IndexError: list index out of range
>
as you see clearly last index [('p1', 10, 3)] has only 1 tuple, hence the IndexError
I want to define sth like
list([[i0,i1,i2,i3, ..., ik]] for i0 in T[0] for i1 in T[1] for i2 in T[2] for i3 in T[3] for ...)
as k is indefinite, I cannot do this like
list([[i0,i1,i2,i3]] for i0 in T[0] for i1 in T[1] for i2 in T[2] for i3 in T[3]).
Is there a general solution?
Many thanks!
Your nested fors will make a Cartesian product of the sublists in T. Itertools has a product() function that will give you an iterator of these values, which you can use like:
from itertools import product
T = [[1, 2, 3], [4, 5, 6], [7, 8, 9], [10,11, 12]]
p = product(*T)
for i in p:
print(i)
(1, 4, 7, 10)
(1, 4, 7, 11)
(1, 4, 7, 12)
(1, 4, 8, 10)
(1, 4, 8, 11)
(1, 4, 8, 12)
(1, 4, 9, 10)
(1, 4, 9, 11)
...
(3, 6, 9, 10)
(3, 6, 9, 11)
(3, 6, 9, 12)
Of course you can also pass it to list() if want the values in a list.
Following is my approach to return the n element in Tribonacci series
def tri(n,seq = [1, 1, 1]):
for i in range(n-2):
seq = seq[1:] + [sum(seq)]
return seq[-1]
I get the correct result when passing argument through print().
print(tri(10))
Output : 193
However, when using generator(using repl.it), I get error of can only concatenate tuple (not"list") to tuple
I am using below for generator
def tri_generator():
for i in range(1000):
yield (i, (1, 1, 1))
yield (i, (1, 0, 1))
yield (i, (1, 2, 3))
Not sure what I am missing? Any help is appreciated.
Here's a simple generator (you can clean up the code as you may like):
def tri_generator():
i = 0
seq = [1, 1, 1]
while True:
seq = [seq[1], seq[2], seq[0] + seq[1] + seq[2]]
yield i, seq
i += 1
n = 10
xx = tri_generator()
for i in range(n - 2):
print(next(xx))
## Output:
## (0, [1, 1, 3])
## (1, [1, 3, 5])
## (2, [3, 5, 9])
## (3, [5, 9, 17])
## (4, [9, 17, 31])
## (5, [17, 31, 57])
## (6, [31, 57, 105])
## (7, [57, 105, 193])