How can I make a square matrix from a nested dict? - python-3.x

I am recently using networkx module, and now I am about to get distance data among countries.
So the excel raw data is something like this:
Nat1 Nat2 Y/N
ABW ANT 0
ABW ARG 0
ABW BEK 1
ABW BHS 1
ABW BRA 0
...
ALB COL 0
ALB CYP 1
...
And thanks to GeckStar(Networkx: Get the distance between nodes), I managed to know how the dataset is coded, as a nested dictionary.
The problem is, I am not familiar with the dictionary. If it was a nested list, I can deal with it, but the nested dict... I need help from others.
So I checked what would this give to me if I code like this:
distance = dict(nx.all_pairs_shortest_path_length(graph))
df = pd.DataFrame(list(distance.items()))
df.to_excel("C_C.xlsx")
(FYI,
distance = dict(nx.all_pairs_shortest_path_length(graph))
will calculate a shortest path from a nation to other nation. So if a nation is not connected to the other nation, and needs a detour, it will has a value more than 1.)
Of course, it didn't go well.
0 1
0 ABW {'ABW':0, 'ANT': 1 ..., 'BHS': 2 ...}
1 ANT {'ANT':0, 'ABW': 1 ...}
...
3 BEL {'BEL':0, 'ABW':1, ... 'BHS':4, ...}
...
But I know there should be a way to make those data to a square matrix like this:
ABW ANT ARG BEL BHS ...
ABW 0 0 0 1 2 ...
ANT 0 0 1 0 1 ...
ARG 0 1 0 1 0 ...
BEL 2 0 1 0 4 ...
...
Can you guys enlighten me, please?
Thanks for your time to check this out, and Thank you for your solution in advance.

I just did a walkaround with a list.
dis = dict(nx.all_pairs_shortest_path_length(graph))
Nations = list(dis.keys())
master = [[""]]
for x in Nations:
master[0].append(x)
for Nat1 in dis:
master.append([Nat1])
for Nat2 in Nations:
master[-1].append(dis[Nat1][Nat2])
Thanks for everyone taking care of this problem.
Have a wonderful day!

Related

Group by id and change column value based on condition

I'm a bit stuck on some code. I've looked through stack and found many similar questions but all are different in some way.
I have a dataframe df_jan which looks like this.
df_jan
ID Date days_since_last_purchase x_1
1 01/01/2020 0 0
1 04/01/2020 3 0
2 04/01/2020 0 0
1 06/02/2020 33 1
Basically x_1 denotes whether it has been over 30 days since their last purchase.
What I want to achieve is if an ID has x_1 = 1 anywhere in its lifetime all the x_1 values for that specific ID is set to 1 like this.
df_jan
ID Date days_since_last_purchase x_1
1 01/01/2020 0 1
1 04/01/2020 3 1
2 04/01/2020 0 0
1 06/02/2020 33 1
I've tried using a .groupby function along with a .loc but it says they can't work together. I also tried modifying the answers to this without much luck.
Thank you in advance for any help you guys can give!
You can groupby and transform, eg:
df['x_1'] = df_jan.groupby('ID')['days_since_last_purchase'].transform(lambda v: int(v.gt(30).any()))

Need help understanding MCNP TMESH tally output

I am trying to understand the the MCTAL output of a spherical TMESH tally. What I want is to create one tally bin that has the following boundaries 1.9 cm and 2.1 cm in the radial direction, 88 to 92 degrees in theta and 180 to 360 degrees in the phi direction. my input for the tally is
C tally card spherical mesh energy tally
TMESH
SMESH1:p DOSE 1 1 1 1.0 PEDEP MFACT 1 1 0 1.0
CORA1 1.9 2.1
CORB1 88 92
CORC1 180 360
Now what I expect is one result for that volume what I get are eight values as shown below.
ntal 1
1
tally 1 -1 -3
0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
f 4 0 1 2 2
1.90000E+00 2.10000E+00
0.00000E+00 8.80000E+01 9.20000E+01
0.00000E+00 1.80000E+02 3.60000E+02
d 1
u 1
s 2
m 1
c 1
e 1
t 1
vals
5.57481E-04 0.0067 7.68088E-09 0.0493 8.24471E-03 0.0046 1.38395E-07 0.0639
5.53931E-04 0.0046 7.44313E-09 0.0287 8.24244E-03 0.0042 1.27868E-07 0.0553
I am assuming that these eight vals correspond to the eight points that that are listed under f. Does TMESH only give one values for individual points on a grid or can it be used to create a volume within which to obtain a result? lastly to what points do what vals correspond to ?
The matrix bellow the vals is true value of your meshtally result.
but
you must load data to Matlab and reshape it to your mesh tally matrix
With your SMESH setup you score both dose and energy deposition. This causes two bins along the segment axis (the "s 2" record in your mctal). Then, you have only 1 bin along the radial direction (1.9-2.1 cm) and actually TWO bins along each of the angular directions (0-88, 88-92, and 0-180, 180-360) which sums up to 2^3 = 8 bins. The mctal file format is described in the manual: it'a 11-dimension loop. In your case only the s, j and k axes are divided, so it's actully a 3D loop (in this exact order: s being the outer, k - the inner loop). Therefore the value for your volume is either the 4th (1.38395E-07 0.0639) or last (1.27868E-07 0.0553) record depending on whether you need dose or energy deposition.

is this Epsilon-NFA correct?

I am exercising and wasn't sure if I got this correct. I had to draw 0* U 1*.
Update: This was correct
yh you are right , This NFA accepts either 0 or 1
so you can say NFA for 0 U 1
as epsilon concatenate with 1 results in 1
or epsilon concatenate with 0 results in 0

in APL how do I turn a vector (of length n) into a diagonal matrix (nxn)?

I had a J program I wrote in 1985 (on vax vms). One section was creating a diagonal matrix from a vector.
a=(n,n)R1,nR0
b=In
a=bXa
Maybe it wasn't J but APL in ascii, but these lines work in current J (with appropriate changes in the primitive functions). But not in APL (gnu , NARS2000 or ELI). I get domain error in the last line.
Is there an easy way to do this without looping?
Your code is an ASCII transliteration of APL. The corresponding J code is:
a=.(n,n)$1,n$0
b=.i.n
a=.b*a
Try it online! However, no APL (as of yet — it is being considered for Dyalog APL) has major cell extension which is required on the last line. You therefore need to specify that the scalars of the vector b should be multiplied with the rows of the matrix a using bracket axis notation:
a←(n,n)⍴1,n⍴0
b←⍳n
a←b×[1]a
Try it online! Alternatively, you can use the rank operator (where available):
a←(n,n)⍴1,n⍴0
b←⍳n
a←b(×⍤0 1)a
Try it online!
A more elegant way to address diagonals is ⍉ with repeated axes:
n←5 ◊ z←(n,n)⍴0 ◊ (1 1⍉z)←⍳n ◊ z
1 0 0 0 0
0 2 0 0 0
0 0 3 0 0
0 0 0 4 0
0 0 0 0 5
Given an input vector X, the following works in all APLs, (courtesy of #Adám in chat):
(2⍴S)⍴((2×S)⍴1,-S←⍴X)\X
And here's a place where you can run it online.
Here are my old, inefficient versions that use multiplication and the outer product (the latter causes the inefficiency):
((⍴Q)⍴X)×Q←P∘.=P←⍳⍴X
((⍴Q)⍴X)×Q←P Pρ1,(P←≢X)ρ0
Or another way:
(n∘.=n)×(2ρρn)ρn←⍳5
should give you the following in most APLs
1 0 0 0 0
0 2 0 0 0
0 0 3 0 0
0 0 0 4 0
0 0 0 0 5
This solution works in the old ISO Apl:
a←(n,n)⍴v,(n,n)⍴0

Generate data following specified pattern in J

I'm dabbling my feet with J and, to get the ball rolling, decided to write a function that:
gets integer N;
spits out a table that follows this pattern:
(example for N = 4)
1
0 1
0 0 1
0 0 0 1
i.e. in each row number of zeroes increases from 0 up to N - 1.
However, being newbie, I'm stuck. My current labored (and incorrect) solution for N = 4 case looks like:
(4 # ,: 0 1) #~/"1 1 (1 ,.~/ i.4)
1 0 0 0
0 1 0 0
0 0 1 0
0 0 0 1
And the problem with it is twofold:
it's not general enough and looks kinda ugly (parens and " usage);
trailing zeroes - as I understand, all arrays in J are homogeneous, so in my case every row should be boxed.
Like that:
┌───────┐
│1 │
├───────┤
│0 1 │
├───────┤
│0 0 1 │
├───────┤
│0 0 0 1│
└───────┘
Or I should use strings (e.g. '0 0 1') which will be padded with spaces instead of zeroes.
So, what I'm kindly asking here is:
please provide an idiomatic J solution for this task with explanation;
criticize my attempt and point out how it could be finished.
Thanks in advance!
Like so many challenges in J, sometimes it is better to keep your focus on your result and find a different way to get there. In this case, what your initial approach is doing is creating an identity matrix. I would use
=/~#:i. 4
1 0 0 0
0 1 0 0
0 0 1 0
0 0 0 1
You have correctly identified the issue with the trailing 0's and the fact that J will pad out with 0's to avoid ragged arrays. Boxing avoids this padding since each row is self contained.
So create your lists first. I would use overtake to get the extra 0's
4{.1
1 0 0 0
The next line uses 1: to return 1 as a verb and boxes the overtakes from 1 to 4
(>:#:i. <#:{."0 1:) 4
+-+---+-----+-------+
|1|1 0|1 0 0|1 0 0 0|
+-+---+-----+-------+
Since we want this as reversed and then made into strings, we add ":#:|.#: to the process.
(>:#:i. <#:":#:|.#:{."0 1:) 4
+-+---+-----+-------+
|1|0 1|0 0 1|0 0 0 1|
+-+---+-----+-------+
Then we unbox
>#:(>:#:i. <#:":#:|.#:{."0 1:) 4
1
0 1
0 0 1
0 0 0 1
I am not sure this is the way everyone would solve the problem, but it works.
An alternative solution that does not use boxing and uses the dyadic j. (Complex) and the fact that
1j4 # 1
1 0 0 0 0
(1 j. 4) # 1
1 0 0 0 0
(1 #~ 1 j. ]) 4
1 0 0 0 0
So, I create a list for each integer in i. 4, then reverse them and make them into strings. Since they are now strings, the extra padding is done with blanks.
(1 ":#:|.#:#~ 1 j. ])"0#:i. 4
1
0 1
0 0 1
0 0 0 1
Taking this step by step as to hopefully explain a little better.
i.4
0 1 2 3
Which is then applied to (1 ":#:|.#:#~ 1 j. ]) an atom at a time, hence the use of "0
Breaking down what is going on within the parenthesis. I first take the right three verbs which form a fork.
( 1 j. ])"0#:i.4
1 1j1 1j2 1j3
Now, effectively that gives me
1 ":#:|.#:#~ 1 1j1 1j2 1j3
The middle tine of the fork becomes the verb acting on the two noun arguments.The ~ swaps the arguments. so it becomes equivalent to
1 1j1 1j2 1j3 ":#:|.#:# 1
which because of the way #: works is the same as
": |. 1 1j1 1j2 1j3 # 1
I haven't shown the results of these components because using the "0 on the fork changes how the arguments that are sent to the middle tine and assembled later. I'm hoping that there is enough here that with some hand waving the explanation may suffice
The jump from tacit to explicit can be a big one, so it may be a better exercise to write the same verb explicitly to see if it makes more sense.
lowerTriangle =: 3 : 0
​rightArg=. i. y
​complexCopy=. 1 j. rightArg
​1 (":#:|.#:#~)"0 complexCopy
​)
lowerTriangle 4
1
0 1
0 0 1
0 0 0 1
lowerTriangle 5
1
0 1
0 0 1
0 0 0 1
0 0 0 0 1
See what happens when you 'get the ball rolling'? I guess the thing about J is that the ball goes down a pretty steep slope no matter where you begin. Exciting, eh?

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