How to extract just floats from list - arrays

I want to get arrays with floats from A,B,C list.
page = requests.get("http://www.arso.gov.si/potresi/obvestila%20o%20potresih/aip/")
soup = BeautifulSoup(page.content, 'html.parser')
all_tables=soup.find_all('table')
right_table=soup.find('table',class_='online')
A=[]
B=[]
C=[]
for row in right_table.findAll("tr"):
cells = row.findAll('td')
if len(cells)==6:
A.append(cells[1].find(text=True))
B.append(cells[2].find(text=True))
C.append(cells[3].find(text=True))
For now I have variables like this:
A=[u'45.50',u'46.00',...]
and I want just floats from list:
A=[45.50,46.00,...]

Just convert the element's text to float type:
...
if len(cells) == 6:
A.append(float(cells[1].text))
B.append(float(cells[2].text))
C.append(float(cells[3].text))
print(A)
print(B)
print(C)
The output:
[45.5, 46.0, 46.07, 45.89, 45.83, 46.1, 46.53, 45.88, 45.84, 45.9, 46.09, 46.39, 45.3, 45.34, 46.7, 45.25, 46.39, 45.5, 46.39]
[14.41, 14.76, 14.22, 14.59, 15.12, 14.42, 14.57, 15.19, 15.18, 14.57, 14.19, 13.39, 14.62, 14.59, 15.23, 14.58, 15.03, 14.4, 15.03]
[1.2, 1.2, 1.0, 0.8, 1.2, 1.0, 1.1, 1.3, 0.8, 0.9, 0.5, 1.0, 1.3, 2.3, 1.4, 1.9, 0.7, 0.8, 0.4]

You could use python2.7 map function to convert each list of strings to a list of floats:
A = map(float, A)
B = map(float, B)
C = map(float, C)
print A # [45.5, 46.0, 46.07, 45.89, 45.83, 46.1, 46.53, 45.88, 45.84, 45.9, 46.09, 46.39, 45.3, 45.34, 46.7, 45.25, 46.39, 45.5, 46.39]
print B # [14.41, 14.76, 14.22, 14.59, 15.12, 14.42, 14.57, 15.19, 15.18, 14.57, 14.19, 13.39, 14.62, 14.59, 15.23, 14.58, 15.03, 14.4, 15.03]
print C # [1.2, 1.2, 1.0, 0.8, 1.2, 1.0, 1.1, 1.3, 0.8, 0.9, 0.5, 1.0, 1.3, 2.3, 1.4, 1.9, 0.7, 0.8, 0.4]

Related

Convert image in list of coordinates in Julia

I have this short code img_lab = rand(Lab, 10, 10) where I just have created an image of random colored pixels. Probably this question is trivial but how do I convert the output of this (which is Matrix{Lab{Float64}} (alias for Array{Lab{Float64}, 2}) to an organized list of coordinates.
For example [[0,0,0.44,0.33,0.45],[0,1, ...] , ... , [10,10,0.54,0.32,0.87]]
where the first two entries are the coordinates and the last three values for RGB.
First, please make sure that you have good reasons to do this. Converting to such a format makes it harder to use the rest of Colors functionality, could have a (potentially large) performance cost, and is usually unnecessary.
Now, assuming it's necessary, here's one way to do it:
julia> using Random; Random.seed!(42)
TaskLocalRNG()
julia> img_lab = rand(Lab, 10, 10)
10×10 Matrix{Lab{Float64}}:
Lab(17.3575, -26.8628, -55.5385) Lab(9.1585, 86.3359, 71.5105) … Lab(14.4465, 87.7468, 12.1242)
Lab(16.6439, 11.0078, -10.1264) Lab(54.2929, -24.2044, -55.6044) Lab(5.5968, 79.2197, -6.69094)
Lab(39.0663, 61.8604, 90.5844) Lab(50.2836, -78.3482, -26.4757) Lab(6.6672, 21.7418, -100.172)
.
.
.
julia> map(keys(img_lab)) do cindex
rgbval = RGB(img_lab[cindex])
[cindex[1], cindex[2], red(rgbval), green(rgbval), blue(rgbval)]
end
10×10 Matrix{Vector{Float64}}:
[1.0, 1.0, 0.0, 0.223779, 0.488699] [1.0, 2.0, 0.468242, 0.0, 0.0] … [1.0, 10.0, 0.513226, 0.0, 0.101153]
[2.0, 1.0, 0.196137, 0.141577, 0.218233] [2.0, 2.0, 0.0, 0.573977, 0.885473] [2.0, 10.0, 0.366805, 0.0, 0.118275]
[3.0, 1.0, 0.737804, 0.0333098, 0.0] [3.0, 2.0, 0.0, 0.583897, 0.639801] [3.0, 10.0, 0.0, 0.136071, 0.65593]
[4.0, 1.0, 0.117582, 0.0803492, 0.209829] [4.0, 2.0, 0.833069, 0.433512, 1.0] [4.0, 10.0, 0.818553, 0.673722, 0.202751]
[5.0, 1.0, 0.0, 0.267613, 0.416236] [5.0, 2.0, 0.0, 1.0, 1.0] [5.0, 10.0, 0.26368, 0.0, 0.0]
[6.0, 1.0, 0.0, 0.703393, 0.0] [6.0, 2.0, 0.89057, 0.980158, 1.0] … [6.0, 10.0, 0.491448, 0.47962, 0.891735]
[7.0, 1.0, 0.0, 1.0, 0.819822] [7.0, 2.0, 1.0, 0.773939, 1.0] [7.0, 10.0, 0.0, 1.0, 1.0]
[8.0, 1.0, 1.0, 0.707005, 0.402694] [8.0, 2.0, 0.0, 0.820631, 1.0] [8.0, 10.0, 0.0, 0.3219, 0.91962]
[9.0, 1.0, 1.0, 0.830982, 0.928663] [9.0, 2.0, 0.0, 0.279664, 0.0] [9.0, 10.0, 0.937227, 0.650945, 0.442197]
[10.0, 1.0, 0.291409, 0.0, 0.28529] [10.0, 2.0, 1.0, 0.682411, 1.0] [10.0, 10.0, 0.0, 0.475448, 0.941526]
(From my limited understanding, Lab-to-RGB conversion is a lossy one - and the number of 0.0s and 1.0s in the color values above seems to indicate that too, values outside the RGB gamut getting clamped to be within its limits.)

Arranging a list based on the distance of its elements from a given value

Let's assume we have a list like the following
[2.3, 1.02, 1.99, 0.99, 0.089, 0, 1.1, -1.1, -2.1]
We want to arrange the elements of this list based on their distance from target value equal to 1 in the following manner:
[0.99, 1.02, 1.1, 0.089, 1.99, 0, 2.3, -1.1, -2.1]
How to do that in python in one or two lines?
python solution
Use sorted with the absolute distance to target as key:
L = [2.3, 1.02, 1.99, 0.99, 0.089, 0, 1.1, -1.1, -2.1]
target = 1
out = sorted(L, key=lambda x: abs(x-target))
output: [0.99, 1.02, 1.1, 0.089, 1.99, 0.0, 2.3, -1.1, -2.1]
numpy solution
Compute the absolute distance and use numpy.argsort:
L = [2.3, 1.02, 1.99, 0.99, 0.089, 0, 1.1, -1.1, -2.1]
target = 1
import numpy as np
a = np.array(L)
out = a[np.argsort(abs(a-target))].tolist()
output: [0.99, 1.02, 1.1, 0.089, 1.99, 0.0, 2.3, -1.1, -2.1]

How to get the print of 3 values?

I want to get prints of mini, maxi, and a8_1, but, instead, I just got the last print.
a8_1 = [-0.7, -1.5, -1.7, 0.3, 1.5, 1.8, 2.0]
a8_1 = np.array(a8_1)
a8_1
mini = a8_1.min()
mini
maxi = a8_1.max()
maxi
Assuming you are using interactive shell, and have already imported the numpy package (which I do not see in the code above), this above code should definitely print all 3.
>>> import numpy as np
>>> a8_1 = [-0.7, -1.5, -1.7, 0.3, 1.5, 1.8, 2.0]
>>> a8_1 = np.array(a8_1)
>>> a8_1
array([-0.7, -1.5, -1.7, 0.3, 1.5, 1.8, 2. ])
>>> mini = a8_1.min()
>>>
>>> mini
-1.7
>>> maxi = a8_1.max()
>>> maxi
2.0
>>>

How to find correspondent elements of two linearly transformed arrays in Ruby?

I have two arrays of floats (x,y) with unique elements, one of them is a linear transform of the other y=a*x+b, for example:
a=0.95;
b1=3.33;
b2=5.55;
x=[1,3,4,6,9,13,20,22,31,35,37,40];
y=t1.collect.with_index{|z,i| i>6 ? z*a+b1 : z*a+b2}
=> [6.5, 8.4, 9.35, 11.25, 14.1, 17.9, 24.55, 24.23, 32.78, 36.58, 38.48, 41.33]
The linear transformation is applied with two different b values to the x array. Let's suppose I don't know the rule of the b values aplied, here the function of the index i.
My goal is that if I know the value of a and I also know the possible values of b in the form of a two element array bs=[b1,b2], then I would like to find out the correspondent b value for every element of y even if the two arrays (x,y) are scrambled. My idea (doesn't work correctly, I need help here):
def ybs(x,y,bs,a)
difference=0.0
xelem=0.0
return y.map do |z|
cb=bs.min_by do |b|
xelem=x.min_by do |q|
(q-(z-b)*1/a).abs
end
difference=(xelem-(z-b)*1/a).abs
end
difference=(xelem-(z-cb)*1/a).abs
[z,xelem,(z-cb)*1/a,cb,difference]
end
end
It would return 4 values for every elements of the y array in the form:
[<value from y>,<correspondent value from x>,<inverse transformed value of y, should be equal to xelem>,<correspondent b value of the linear transformation>,<difference, error, usually 0.0>]
My output when I call ybs(x,y,bs,a):
[[1, 6.5, -2.4526315789473685, 3.33, 8.952631578947368],
[3, 6.5, -0.34736842105263166, 3.33, 6.847368421052631],
[4, 6.5, 0.7052631578947368, 3.33, 5.794736842105263],
[6, 6.5, 2.8105263157894735, 3.33, 3.6894736842105265],
[9, 6.5, 5.968421052631579, 3.33, 0.5315789473684207],
[13, 8.4, 7.842105263157896, 5.55, 0.5578947368421048],
[20, 14.1, 17.547368421052635, 3.33, 3.4473684210526354],
[22, 17.9, 17.31578947368421, 5.55, 0.5842105263157897],
[31, 24.55, 26.789473684210527, 5.55, 2.2394736842105267],
[35, 32.78, 33.33684210526316, 3.33, 0.5568421052631578],
[37, 32.78, 33.10526315789474, 5.55, 0.3252631578947387],
[40, 36.58, 38.6, 3.33, 2.020000000000003]]
I need this method for my subtitle syncing program, where different parts of the subtitles' time codes can be shifted by different amount, for example when a scene is missing from a different version of the movie.
The problem was that you weren't keeping your ordered pairs together. For each y value, your code 'thinks' that the x associated with it is the one for which (q-(z-b)*1/a).abs is the least. However, it could be that taking the "wrong" b value for the y value being considered, together with the wrong x value would lead to a value of (q-(z-b)*1/a).abs that was slightly (or much) less than that which you get by taking the "right" b and x values.
I ran your code (rounding off the values for clarity) and got:
[6.5, 1.0, 1.0, 5.55, 0.0]
[8.4, 3.0, 3.0, 5.55, 0.0]
[9.35, 4.0, 4.0, 5.55, 0.0]
[11.25, 6.0, 6.0, 5.55, 0.0]
[14.1, 9.0, 9.0, 5.55, 0.0]
[17.9, 13.0, 13.0, 5.55, 0.0]
[24.55, 20.0, 20.0, 5.55, 0.0]
[24.23, 20.0, 22.0, 3.33, 2.0]
[32.78, 31.0, 31.0, 3.33, 0.0]
[36.58, 31.0, 35.0, 3.33, 4.0]
[38.48, 35.0, 37.0, 3.33, 2.0]
[41.33, 37.0, 40.0, 3.33, 3.0]
You can see that the x values do not follow the original sequence. Since there's no need to take a chance letting 'y's get associated with the wrong 'x's, lets just force them to stay together.
Here is how I modified your code to keep the ys and xs together.
def ybs(pairs,bs,a)
difference=0.0
xelem=0.0
return pairs.map do |pair|
x,y = pair[0], pair[1]
cb = bs.min_by do |b|
(x-(y-b)*1/a).abs
end
difference = (x-(y-cb)*1/a).abs
[y,x,(y-cb)*1/a,cb,difference]
end
end
a=0.95;
b1=3.33;
b2=5.55;
bs = [b1, b2]
x=[1,3,4,6,9,13,20,22,31,35,37,40];
y=x.collect.with_index{|z,i| i>6 ? z*a+b1 : z*a+b2}
c = x.count-1
pairs = (0..c).collect do |i|
[x[i],y[i]]
end
r = ybs(pairs,bs,a)
r.each do |q|
(0..4).each do |p|
q[p] = q[p].round(2)
end
p q
end
and here is my output:
[6.5, 1.0, 1.0, 5.55, 0.0]
[8.4, 3.0, 3.0, 5.55, 0.0]
[9.35, 4.0, 4.0, 5.55, 0.0]
[11.25, 6.0, 6.0, 5.55, 0.0]
[14.1, 9.0, 9.0, 5.55, 0.0]
[17.9, 13.0, 13.0, 5.55, 0.0]
[24.55, 20.0, 20.0, 5.55, 0.0]
[24.23, 22.0, 22.0, 3.33, 0.0]
[32.78, 31.0, 31.0, 3.33, 0.0]
[36.58, 35.0, 35.0, 3.33, 0.0]
[38.48, 37.0, 37.0, 3.33, 0.0]
[41.33, 40.0, 40.0, 3.33, 0.0]
All of the errors are small, and the bs are correct... they are 5.55 until the 7th row, where they switch to 3.33, as your rule prescribes.

How do I append one matrix to another in Scala?

If I have the following code:
var A = Array[Array[Double]]() // where A becomes an MxP matrix
var B = Array[Array[Double]]() // where B becomes an NxP matrix
What are some efficient ways to append one matrix to the other, resulting in a single matrix, as the following pseudocode would suggest?
val C = A append B // where C is a (M+N)xP matrix
Obviously, one of the dimensions (in this case P) is held constant.
EDIT: So far, both of the provided solutions are growing in the second dimension. I am trying to hold the second dimension fixed.
Functional, but not as performant as the imperative alternative would be:
scala> val a = Array.tabulate(2, 3)((_, _) => (math.random * 100).toInt)
a: Array[Array[Int]] = Array(Array(52, 61, 58), Array(35, 69, 39))
scala> val b = Array.tabulate(2, 4)((_, _) => (math.random * 100).toInt)
b: Array[Array[Int]] = Array(Array(51, 54, 87, 10), Array(52, 76, 18, 85))
scala> (a, b).zipped.map(_ ++ _)
res0: Array[Array[Int]] = Array(Array(52, 61, 58, 51, 54, 87, 10), Array(35, 69, 39, 52, 76, 18, 85))
(In reply to the comment...)
Holding the second dimension fixed:
scala> val x = Array.tabulate(3, 2)((_, _) => (math.random * 100).toInt)
x: Array[Array[Int]] = Array(Array(13, 26), Array(96, 6), Array(68, 58))
scala> val y = Array.tabulate(2, 2)((_, _) => (math.random * 100).toInt)
y: Array[Array[Int]] = Array(Array(82, 5), Array(0, 76))
scala> x ++ y
res1: Array[Array[Int]] = Array(Array(13, 26), Array(96, 6), Array(68, 58), Array(82, 5), Array(0, 76))
scala> val a = Array.fill(4,3) { 1. };
a: Array[Array[Double]] = Array(Array(1.0, 1.0, 1.0), Array(1.0, 1.0, 1.0), Array(1.0, 1.0, 1.0), Array(1.0, 1.0, 1.0))
scala> val b = Array.fill(4,6) { 2. };
b: Array[Array[Double]] = Array(Array(2.0, 2.0, 2.0, 2.0, 2.0, 2.0), Array(2.0, 2.0, 2.0, 2.0, 2.0, 2.0), Array(2.0, 2.0, 2.0, 2.0, 2.0, 2.0), Array(2.0, 2.0, 2.0, 2.0, 2.0, 2.0))
scala> for((aa,bb) <- a zip b) yield (aa ++ bb)
res0: Array[Array[Double]] = Array(Array(1.0, 1.0, 1.0, 2.0, 2.0, 2.0, 2.0, 2.0, 2.0), Array(1.0, 1.0, 1.0, 2.0, 2.0, 2.0, 2.0, 2.0, 2.0), Array(1.0, 1.0, 1.0, 2.0, 2.0, 2.0, 2.0, 2.0, 2.0), Array(1.0, 1.0, 1.0, 2.0, 2.0, 2.0, 2.0, 2.0, 2.0))

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