The program should be like this:
together((0,39,100,210),(4,20))
printing the following:
(0,4,20,39,100,210)
The code:
def together(s,t):
y = s + t
z = 0
if sorted(y) == y:
print (y)
else:
for i in range(len(y)-1):
if y[z] > y[z+1]:
y[z+1] = y[z]
return (y)
print y
If variables are set like the following:
s=1,23,40
and
t=9,90
I´m getting this:
(1, 23, 40, 9, 90)
which is out of order as you can see it should appear the following:
(1,9,23,40,90)
Is there any other way you could do this by using comparatives to see if the numbers from the 'y' variable are already sorted and if not do it to the whole scheme?
Using a type of code like this one where you use to see what´s the bigger number:
def bigger(t):
bigger = 0
for i in range(len(t)-1):
if t[i] > bigger:
bigger = t[i]
return bigger
Is this possible for getting the same result that you get by doing the solution above?
T = ((0,39,100,210),(4,20))
print tuple( sorted( reduce(tuple.__add__, T) ) )
T is your together tuple....This uses reduce, and in-built __add__ function of tuples to do the job...
Related
I'm trying to calculate the total sum of squares using python.
I know that the formula of TSS is:
[enter image description here][1]
I created a code to do it:
from statistics import mean
x = ([3,1,3,1,3,13])
def tss(a):
m = mean(a)
for i in a:
i += ((i-m)**2)
return (i)
print(tss(x))
The problem is: Its keeping returning me 94, but i know that the correct answer is 102. I don't have a clue of what i did wrong. Can anybody help me?
[1]: https://i.stack.imgur.com/Alx6r.png
i is resetting each time it goes through the loop. So on the last loop your function erases all the previous sums, sets i to 13, then adds the square of the difference between 13 and the mean to i (which is now 13), returning 94. You need a different variable to track the sum, so it doesn't get lost each loop. You want:
from statistics import mean
x = ([3,1,3,1,3,13])
def tss(a):
m = mean(a)
n = 0
for i in a:
n += ((i-m)**2)
return (n)
print(tss(x))
'''
#mateen's answer is more pythonic and will perform better than a loop, but I don't think you'll get the understanding from it. Welcome to python!
If you want to keep your initial script , just do :
from statistics import mean
x = ([3, 1, 3, 1, 3, 13])
def tss(a):
total = 0
for i in a:
total = total + ((i-mean(a))**2)
return total
Without numpy:
def tss(xs):
m = sum(xs) / len(xs)
return sum((x - m)**2 for x in xs)
With numpy:
import numpy as np
def tss(x):
return ((x - np.mean(x))**2).sum()
** I modified the entire question **
I have an example list specified below and i want to find if 2 values are from the same list and i wanna know which list both the value comes from.
list1 = ['a','b','c','d','e']
list2 = ['f','g','h','i','j']
c = 'b'
d = 'e'
i used for loop to check whether the values exist in the list however not sure how to obtain which list the value actually is from.
for x,y in zip(list1,list2):
if c and d in x or y:
print(True)
Please advise if there is any work around.
First u might want to inspect the distribution of values and sizes where you can improve the result with the least effort like this:
df_inspect = df.copy()
df_inspect["size.value"] = ["size.value"].map(lambda x: ''.join(y.upper() for y in x if x.isalpha() if y != ' '))
df_inspect = df_inspect.groupby(["size.value"]).count().sort_values(ascending=False)
Then create a solution for the most occuring size category, here "Wide"
long = "adasda, 9.5 W US"
short = "9.5 Wide"
def get_intersection(s1, s2):
res = ''
l_s1 = len(s1)
for i in range(l_s1):
for j in range(i + 1, l_s1):
t = s1[i:j]
if t in s2 and len(t) > len(res):
res = t
return res
print(len(get_intersection(long, short)) / len(short) >= 0.6)
Then apply the solution to the dataframe
df["defective_attributes"] = df.apply(lambda x: len(get_intersection(x["item_name.value"], x["size.value"])) / len(x["size.value"]) >= 0.6)
Basically, get_intersection search for the longest intersection between the itemname and the size. Then takes the length of the intersection and says, its not defective if at least 60% of the size_value are also in the item_name.
import numpy as np
x = ([1,2,3,3])
y = ([1,2,3])
z = ([6,6,1,2,9,9])
(only positive values)
In each array i need to return the most common value, or, if values come up the same amount of times - return the minimum.
This is home assignment and I can't use anything but numpy.
outputs:
f(x) = 3,
f(y) = 1,
f(z) = 6
for a numpy exclusive solution something like this will work:
occurances = np.bincount(x)
print (np.argmax(occurances))
The above mentioned method won't work if there is a negative number in the list. So in order to account for such an occurrence kindly use:
not_required, counts = np.unique(x, return_counts=True)
x=np.array(x)
if (x >= 0).all():
print(not_required[np.argmax(counts)])
else:
print(not_required[np.argmax(counts)])
It's called a mode function. See https://docs.scipy.org/doc/scipy/reference/generated/scipy.stats.mode.html
Without numpy
n_dict = {}
for k in x:
try:
n_dict[k] += 1
except KeyError:
n_dict[k] = 1
rev_n_dict = {}
for k in n_dict:
if n_dict[k] not in rev_n_dict:
rev_n_dict[n_dict[k]] = [k]
else:
rev_n_dict[n_dict[k]].append(k)
local_max = 0
for k in rev_n_dict:
if k > local_max:
local_max = k
if len(rev_n_dict[local_max]) > 0:
print (min(rev_n_dict[local_max]))
else:
print (rev_n_dict[local_max])
To add to the previous results, you could use a collections.Counter object:
my_array = [3,24,543,3,1,6,7,8,....,223213,13213]
from collections import Counter
my_counter = Counter( my_array)
most_common_value = my_counter.most_common(1)[0][0]
It is quite simple but certainly not pretty. I have used variable names that will be self explanatory along with the comments. Feel free to ask if there is a doubt.
import numpy as np
x=([6,6,1,2,9,9])
def tester(x):
not_required, counts = np.unique(x, return_counts=True)
x=np.array(x)
if (x >= 0).all():
highest_occurance=[not_required[np.argmax(counts)]]
number_of_counts=np.max(counts)
else:
highest_occurance=not_required[np.argmax(counts)]
number_of_counts=np.max(counts)
return highest_occurance,number_of_counts
most_abundant,first_test_counts=(tester(x))
new_x=[vals for vals in x if vals not in most_abundant]
second_most_abundant,second_test_counts=(tester(new_x))
if second_test_counts==first_test_counts:
print("Atleast two elements have the same number of counts",most_abundant," and", second_most_abundant, "have %s"%first_test_counts,"occurances")
else:
print("%s occurrs for the max of %s times"%(most_abundant,first_test_counts))
we can also loop it to check if there are more than two elements with the same occurrence, instead of using an if else for a specific case of only looking at two elements
I am working in SageMath (Python-based), I am quite new to programming and I have the following question. In my computations I have a quadratic form: x^TAx = b , where the matrix A is defined already as a symmetric matrix, and x is defined as
import itertools
X = itertools.product([0,1], repeat = n)
for x in X:
x = vector(x)
print x
as all combination of [0,1] repeated n times. I got a set of values for b the following way:
import itertools
X = itertools.product([0,1], repeat = n)
results = []
for x in X:
x = vector(x)
x = x.row()
v = x.transpose()
b = x * A * v
results.append(b[0, 0])
And then I defined:
U = set(results)
U1 = sorted(U)
A = []
for i in U1:
U2 = round(i, 2)
A.append(U2)
So I have a sorted set to get a few minimal values of my results. I need to extract minimal values from the set and identify what particular x is corresponding to each value of b. I heard that I can use dictionary method and define preimages in there, but I am really struggling to define my dictionary as {key: value}. Could someone help me please, solve the problem or give me the idea of what direction should I think in? Thank you.
So i'm currently working on code, which solves simple differentials. For now my code looks something like that:
deff diff():
coeffs = []
#checking a rank of a function
lvl = int(raw_input("Tell me a rank of your function: "))
if lvl == 0:
print "\nIf the rank is 0, a differential of a function will always be 0"
#Asking user to write coefficients (like 4x^2 - he writes 4)
for i in range(0, lvl):
coeff = int(raw_input("Tell me a coefficient: "))
coeffs.append(coeff)
#Printing all coefficients
print "\nSo your coefficients are: "
for item in coeffs:
print item
And so what I want to do next? I have every coefficient in my coeffs[] list. So now I want to take every single one from there and assign it to a different variable, just to make use of it. And how can I do it? I suppose I will have to use loop, but I tried to do so for hours - nothing helped me. Sooo, how can I do this? It would be like : a=coeff[0], b = coeff[1], ..., x = coeff[lvl] .
Just access the coefficients directly from the list via their indices.
If you are wanting to use the values in a different context that entails making changes to the values but you want to keep the original list unchanged then copy the list to a new list,
import copy
mutableCoeffs = copy.copy(coeffs)
You do not need new variables.
You already have all you need to compute the coefficients for the derivative function.
print "Coefficients for the derivative:"
l = len(coeffs) -1
for item in coeffs[:-1]:
print l * item
l -=1
Or if you want to put them in a new list :
deriv_coeffs = []
l = len(coeffs) -1
for item in coeffs[:-1]:
deriv_coeffs.append(l * item)
l -=1
I guess from there you want to differenciate no? So you just assign the cofficient times it rank to the index-1?
deff diff():
coeffs = []
#checking a rank of a function
lvl = int(raw_input("Tell me a rank of your function: "))
if lvl == 0:
print "\nIf the rank is 0, a differential of a function will always be 0"
#Asking user to write coefficients (like 4x^2 - he writes 4)
for i in range(0, lvl):
coeff = int(raw_input("Tell me a coefficient: "))
coeffs.append(coeff)
#Printing all coefficients
print "\nSo your coefficients are: "
for item in coeffs:
print item
answer_coeff = [0]*(lvl-1)
for i in range(0,lvl-1):
answer_coeff[i] = coeff[i+1]*(i+1)
print "The derivative is:"
string_answer = "%d" % answer_coeff[0]
for i in range(1,lvl-1):
string_answer = string_answer + (" + %d * X^%d" % (answer_coeff[i], i))
print string_answer
If you REALLY want to assign a list to variables you could do so by accessing the globals() dict. For example:
for j in len(coeffs):
globals()["elm{0}".format(j)] = coeffs[j]
Then you'll have your coefficients in the global variables elm0, elm1 and so on.
Please note that this is most probably not what you really want (but only what you asked for).