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Questions tagged [inversion]

The inversion tag is most often used with postings about matrix inversion or data transformations of a similar nature such as color inversion. In addition to the [inversion] tag, you should also specify a tag that indicates the nature of the inversion such as [matrix] or [colors] as most people will do a search not only on the tag [inversion] but also a qualifying tag indicating the kind of inversion.

Inversion in a sequence (A1 . . . An) of n distinct numbers is a pair (i, j) such that i < j and Ai > Aj.
Inversion number of a sequence is one common measure of its sortedness.

Inversion is a general purpose tag indicating a type of transformation to data whether that data is in the form of a matrix, an image (can be considered a matrix of pixels with color values), or some other form of structured data.

When using the [inversion] tag also provide a qualifying tag such as [matrix] or [colors] or other tag which indicates the kind or type of data that is being inverted.

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Lagrange Inversion Formula

Is there any simple way to prove the Taylor's Expansion Formula of inverse functions ? How Lagrange Inversion Formula can be proven ? Is there any easy way to make it ? thank you Since if f(a) = b then f^(-1)(b) = a, it is easy to understand the…
quantum77
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Is (FFFFFF XOR HexColor) equivalent to (FFFFFF - HexColor)?

I have searched Stack Overflow for color inversion algorithms. Most responses involve separating channel values and calculating the respective differences of FF and said values, e.g. HexColor = 3DB5B1 InvRed = FF - 3D = C2 InvGreen = FF…
Tom
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Given array=[72,20,73,42,11,80,39,30,100,46,88,32,21], using quicksort, what is the max number of inversions removed by a single comparsion and swap

Using 72 as pivot, I reached [72,20,42,11,39,30,46,32,21,73,88,80,100]. Here number of inversions is 22. After swapping pivot(72) and 21, the number of inversions is 11 so I am getting max. number of inversions removed to be 11. Is this correct or…
Aman Kumar
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Eigen and Boost matrix inversions give different results

I'm currently building a C++ code that uses matrix inversion. Looking for a library to do this, I noticed that Boost and Eigen3 give different results when inverting my 18x18 matrix ! The difference is not negligible, and therefore leads my…
ConanLord
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Inversion count gives error on large inputs

The given code is for counting the inversions in the given array or we can say to count the number of changes to be made in an array so that it becomes sorted. Code is working fine for the inputs lower than 10**5 but above that it is giving error…
Harsh
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How can I set exceptions to the 'invert' property in css?

I want to invert colors via the css property 'invert' (for dark mode), but at the same time I want to leave 5 specific color to stay the same, and other 5 specific colors - not to invert, but to transform into specifically set 5 colors. Images are…
MiniDuos
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Why my inversions of matrices are such slow with LAPACKE in C++ : MAGMA Alternative and set up

I am using LAPACK to inverse a matrix: I did a reference passing, i.e by working on the address. Here below the function with an input matrix and an output matrix referenced by their address. The issue is that I am obliged to convert the F_matrix…
user1773603
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Index 5 out of bounds for length at Simple_Inversions.main(Simple_Inversions.java:24)

-The main function of my programm is counting the inversion of an array. Examples: input: 5 0 1 2 3 4 (first input is the length of the array) output: 0 (because all numbers are in the right order) input: 5 4 3 2 1 0 output: 4 input: 5 0 1 2 4…
Rauhl
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How to find the inverse of a matrix? (step by step solution)

How to find the inverse of a matrix in Python by hand? Reasons you might want to do this: I need to learn how to inverse a matrix for a school project. I'm interested in calculating the inverse of a matrix using a programming language.
Mark
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Huh? Where do I put my service so that my Controller and Service aren't impossible to test?

Am I correct to think that I have to create my controller by passing it an instance of my context AND my Service to make it testable? For example: new Controller(mycontext,myservice) I'm thinking this is the way I need to change my code, but I…
Doug Chamberlain
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How do I optimize this code that counts of inversions to sort an array in C++?

I'm trying to answer this test from Geeks for Geeks to count the number of inversions some array need to be sorted. I know my code works but they need me to optimize my code in order to post it. The register keyword was something I implemented, but…
user5323331
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How to count inversions faster

I am trying to make my inversion counting program run faster since I am continuously getting TLE. I used C++ and this is my code #include #include using namespace std; int main() { int n; int count = 0; cin >> n; …
mimi
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Why is this 8-puzzle solvable?

So i am writing a program to solve 8 puzzle using BFS,A*, and UCS. The goal state is fixed according to the assignment which is given as: Goal State: |1 2 3| |8 4| |7 6 5| My Initial State: | 1 2| |8 4 3| |7 6 5| However, upon writing a…
Jaime Garcia
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Counting inversions of 2D pair (x,y) in a list

The question is just like normal counting inversion question, but instead of a list of single numbers, now the input is a list of (x,y) pair. For a list of pairs [(x1,y1),(x2,y2),(x3,y3),...,(xn,yn)], a pair (i,j) is a inversion iff i < j and xi>xj,…
YS.An
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Inversion Checker using Insertion Sort

I need to output a group of letters that are that are out of order with respect to the number of inversions of each other. For example, the sequence “AACEDGG” has only 1 inversion (E and D) while the sequence “ZWQM” has 6 inversions. I don't…
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