In swift I have an array like this:
var array = [ 70, 75, 0, 0, 0, 87, 90, 85, 0]
What I want to do is when the value is 0 it will copy the previous first value which is not equal to 0. So the output will become:
[ 70, 75,75, 75, 75, 87, 90, 85, 85]
I’ve tried this code below:
func fillingEmpValues(dataArray:[Int]) -> [Int?] {
var newValue = [Int]()
var array = dataArray
for (index, var element) in array.reversed().enumerated() {
if (element == 0) { // if element is 0
if(index != 0) { // if the index is not 0 proceed
array[index] = (dataArray.reversed()[index-1])
}
}
}
return newValue
}
But the codes above is not working as I expected the output is still the same. What am i MISSING? Thanks
Your code does not work because nothing is appended to newValue. Please notice the yellow warnings.
My suggestion uses a temporary variable (temp).
In the loop
if the value != 0 the value is appended and the temporary variable is set to the value.
if the value == 0 the temporary variable is appended.
func fillingEmpValues(dataArray:[Int]) -> [Int] {
var newValue = [Int]()
var temp = 0
for element in dataArray {
if element != 0 {
newValue.append(element)
temp = element
} else {
newValue.append(temp)
}
}
return newValue
}
let array = [ 70, 75, 0, 0, 0, 87, 90, 85, 0]
let filledArray = fillingEmpValues(dataArray: array) // [70, 75, 75, 75, 75, 87, 90, 85, 85]
Note: Why is your return value [Int?]? Optionals are not involved at all.
Edit:
The other condition in the comments can be accomplished with
func fillingEmpValues(dataArray:[Int]) -> [Int] {
var newValue = [Int]()
var temp = dataArray.first{ $0 != 0 } ?? 0
for (index, element) in dataArray.enumerated() {
if element != 0 {
newValue.append(element)
} else {
temp = dataArray.dropFirst(index).first{ $0 != 0 } ?? temp
newValue.append(temp)
}
}
return newValue
}
let array = [ 0, 0, 83, 0, 0, 87, 90, 85, 0]
let filledArray = fillingEmpValues(dataArray: array) // [83, 83, 83, 87, 87, 87, 90, 85, 85]
I might suggest using reduce(into:):
let array = [70, 75, 0, 0, 0, 87, 90, 85, 0]
let array2 = array.reduce(into: [Int]()) { (result, value) in
if value == 0 {
result.append(result.last ?? 0)
} else {
result.append(value)
}
}
Yielding:
[70, 75, 75, 75, 75, 87, 90, 85, 85]
I feel like there should be an easy way to do this but I can not find a solution online. I'm looking for a one liner something pythonic.
I know you can do this:
Img[:,:,2]=200
but how can you add a condition to this?
if Img[:,:,2]<=100: 200
or
image =[i==100 for i in Img[:,:,2] if i <= 100]
Thanks
To simulate if a[:,:,2]<=100: 200, we can use np.where -
a[:,:,2] = np.where(a[:,:,2] <= 100, 200, a[:,:,2])
Or simply use the mask to assign -
a[a[:,:,2] <= 100,2] = 200
Sample run -
In [379]: a
Out[379]:
array([[[ 78, 134, 7],
[154, 37, 146],
[ 39, 95, 13]],
[[114, 138, 100],
[175, 198, 148],
[ 39, 130, 37]]])
In [380]: a[a[:,:,2] <= 100,2] = 200
In [381]: a
Out[381]:
array([[[ 78, 134, 200],
[154, 37, 146],
[ 39, 95, 200]],
[[114, 138, 200],
[175, 198, 148],
[ 39, 130, 200]]])
I have 2 data points as below, on plotting them I see a weired y axisl, in spite of explicitly enforcing set_yaxis - what I am doing wrong ?
xs =
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199]
ys=
[10828623, 5274952, 1085078, 901346, 605910, 569867, 531991, 514140, 466894, 460954, 439024, 379639, 378027, 354425, 302439, 300041, 285898, 268924, 255451, 251349, 244723, 239494, 236684, 231563, 227331, 225260, 215933, 185900, 183423, 183165, 181345, 171513, 168599, 161532, 155134, 152262, 149294, 145263, 144888, 142472, 139841, 137502, 136515, 127380, 126405, 123018, 121811, 116477, 116447, 111383, 106975, 104696, 93530, 92810, 91116, 89956, 88917, 88487, 87681, 86163, 80010, 75076, 74987, 70867, 70330, 69812, 69017, 68317, 67876, 64657, 63097, 62950, 61399, 59045, 58973, 56203, 55505, 54397, 53311, 52447, 50366, 49832, 48918, 47895, 47157, 46534, 45062, 44127, 43042, 42016, 41045, 39971, 39723, 39090, 36163, 35637, 34947, 33352, 31036, 30218, 29766, 29238, 28952, 25899, 25799, 25770, 25159, 24403, 23485, 22593, 22219, 21363, 21207, 20822, 20682, 19827, 19725, 19293, 18411, 17757, 17169, 17046, 16569, 16408, 16248, 16073, 16030, 15775, 14065, 13921, 13529, 13136, 12633, 12213, 12092, 11659, 10983, 10871, 10712, 10679, 10110, 9981, 9687, 9494, 8597, 8241, 8042, 7948, 7896, 7602, 7543, 6734, 6529, 6372, 6095, 6038, 5708, 5679, 5234, 5175, 4941, 4936, 4806, 4222, 4153, 4102, 4079, 3767, 3673, 3538, 3483, 3408, 3350, 3305, 3253, 3121, 3105, 3061, 2894, 2642, 2604, 2600, 2585, 2306, 2294, 2199, 2140, 2035, 1916, 1639, 1619, 1598, 1469, 1393, 1276, 1219, 1160, 1132, 1068, 1010]
# A stripped down code.
import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
df1=pd.read_csv(path,sep=',',header='infer')
xs=df1["col1"] # see values above
ys=df1["col1"] # ys was orignally float , and I converted it to int.
ax1.set_ylim(min(ys),max(ys))
#(1010, 10828623)
plt.plot(xs,ys)
ax1.set_ylim(min(ys),max(ys))
#(1010, 10828623)
This is because there is a point that is 10 million + - is there a way to keep this point and yet represent this in the plot ?
Also, given that the range is so spread out, I would expect it not to show 0.4 etc, but actual numbers ,even if in the scientific notation.
plt.show()
**for i in range(a):
p=int(raw_input("Enter Elements in List1:"))
list1.append(p)
d1=defaultdict(int)
for item in list1:
d1[item]+=1
print list1
print d1.items()
print ""**
How to compare tuple values in the following list output?
Here my answer should return the tuple values (207,2), (208,1) and (209,1) because those are same in both the lists.
input1 : [203, 203, 204, 204, 205, 206, 207, 208, 207, 209]
output1: [(203, 2), (204, 2), (205, 1), (206, 1), (207, 2), (208, 1), (209, 1)]
input2: [204, 203, 205, 205, 206, 206, 207, 207, 208, 209, 205, 206, 205]
output2: [(203, 1), (204, 1), (205, 4), (206, 3), (207, 2), (208, 1), (209, 1)]
You can use Counter
>>> from collections import Counter
>>> lst = [203, 203, 204, 204, 205, 206, 207, 208, 207, 209]
>>> freqs = Counter(lst)
>>> freqs
Counter({203: 2, 204: 2, 207: 2, 205: 1, 206: 1, 208: 1, 209: 1})
>>> lst2 = [204, 203, 205, 205, 206, 206, 207, 207, 208, 209, 205, 206, 205]
>>> Counter(lst2)
Counter({205: 4, 206: 3, 207: 2, 203: 1, 204: 1, 208: 1, 209: 1})
First compare method:
>>> [ k for k,v in Counter(lst2).iteritems() if v == Counter(lst)[k] ]
[207, 208, 209]
Second compare method:
>>> for k,v in Counter(lst2).iteritems():
... if v == Counter(lst)[k]:
... print k
...
207
208
209
I have a list:
def clc = [[1, 15, 30, 42, 48, 100], [58, 99], [16, 61, 85, 96, 98], [2, 63, 84, 90, 91, 97], [16, 61, 85, 96], [23, 54, 65, 95], [16, 29, 83, 94], [0, 31, 42, 93], [33, 40, 51, 56, 61, 62, 64, 89, 92], [0, 63, 84, 90, 91]]
and a sublist
def subclc = [[1, 15, 30, 42, 48, 100], [58, 99], [16, 61, 85, 96, 98], [2, 63, 84, 90, 91, 97]]
I need to remove sublist from original list
I do so:
subclc.each{
clc.remove(it)
}
but it throws an exceprion Exception in thread "main" java.util.ConcurrentModificationException
I do not understand where is problem and how to solve the problem
Short answers:
For more groovyness and immutability, preserving the original list:
def removed = clc - subclc
assert removed == [[16, 61, 85, 96], [23, 54, 65, 95], [16, 29, 83, 94], [0, 31, 42, 93], [33, 40, 51, 56, 61, 62, 64, 89, 92], [0, 63, 84, 90, 91]]
And the java way, changing the original list:
clc.removeAll subclc
assert clc == [[16, 61, 85, 96], [23, 54, 65, 95], [16, 29, 83, 94], [0, 31, 42, 93], [33, 40, 51, 56, 61, 62, 64, 89, 92], [0, 63, 84, 90, 91]]
Long answer:
You are Iterator-ing through a list while changing the list. In this case you are better using Iterator.remove(), which is being abstracted by the foreach loop.
When you change the list using the foreach loop, you bump into the iterator checks for modification using checkForComodification(). Getting the iterator explicitly works:
list1 = [10,20,30,40,50,60,70,80,90]
list2 = [50,60,80]
def iter = list1.iterator()
while (iter.hasNext()) {
def item = iter.next()
if (list2.contains(item)) iter.remove()
}
assert list1 == [10,20,30,40,70,90]
Or you can use indexes. Note you need to control the index:
list1 = [10,20,30,40,50,60,70,80,90]
list2 = [50,60,80]
for (int i = 0; i < list1.size(); i++) {
def item = list1[i]
if (list2.contains(item)) { list1.remove i-- }
}
assert list1 == [10,20,30,40,70,90]