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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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What is Dependency Injection and Inversion of Control in Spring Framework?

"Dependency Injection" and "Inversion of Control" are often mentioned as the primary advantages of using the Spring framework for developing Web frameworks Could anyone explain what it is in very simple terms with an example if possible?
Chillax
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TypeError: slice indices must be integers or None or have an __index__ method

When running the code in IDLE gives the following error: Traceback (most recent call last): File "C:/Python34/inversion3.py", line 44, in nInversions.inversionMergeSort(m) File "C:/Python34/inversion3.py", line 16, in…
jarvis
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How to invert colors of an image in pygame?

I have a pygame Surface and would like to invert the colors. Is there any way quicker & more pythonic than this? It's rather slow. I'm aware that subtracting the value from 255 isn't the only definition of an "inverted color," but it's what I want…
Ain Britain
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Why Coq doesn't allow inversion, destruct, etc. when the goal is a Type?

When refineing a program, I tried to end proof by inversion on a False hypothesis when the goal was a Type. Here is a reduced version of the proof I tried to do. Lemma strange1: forall T:Type, 0>0 -> T. intros T H. inversion H. (* Coq refuses…
larsr
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How to inverse matrix and integer result in Octave?

I would like to get an invertible matrix in Octave but as integers matrix, so: x = [9,15;19,2]; inv(x) Here I get: [-0.0074906, 0.0561798; 0.0711610, -0.0337079] but I would like to get [22,17;25,21] anyone knows how to invert a matrix?
J.R.
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How to manipulate strings in GO to reverse them?

I'm trying to invert a string in go but I'm having trouble handling the characters. Unlike C, GO treats strings as vectors of bytes, rather than characters, which are called runes here. I tried to do some type conversions to do the assignments, but…
Valney Faria
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Algorithm to generate an array with n length and k number of inversions in O(n log n) time?

I'm writing an algorithm that will return an array with determined length and number of inversions (number pairs, where the left side number is larger than the right side number). I.e. array [3, 1, 4, 2] contains three inversions (3, 1), (3, 2) and…
Mikael Törnwall
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Get enable/disable status and of accessibility Colour inversion mode

In my application i need to make some UI changes when user enable accessibility colour inversion mode. Do we have any api to check enable/disable status of colour inversion mode in android?
Ashok Reddy Narra
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Count number of intervals containing another interval?

Given two lists each containing N intervals (subset of the number line), each interval with form of a start point and endpoint. How many pairs of these intervals from one list contains intervals from another list? For example: If list A is {(1,7),…
tattvabodha
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Inversing the goal of neural networks

I am studying neural networks, or more specifically image classification at the moment. While I was reading, I was wondering if the following has ever been done/ is doable. If anybody could point me to some sources or ideas, I'd appreciate it! In a…
RunOrVeith
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Inverting an obviously untrue hypothesis does not prove falsehood

I am trying to prove a trivial lemma, which is a recreation of a situation I found myself in at another point. Lemma Sn_neq_n: forall n, S n <> n. The proof seems as simple as it gets: Proof. unfold not. intros. Now my goal state shows: n : nat H…
limp_chimp
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alternatives or speedups for mpmath matrix inversion

I'm writing some code in python that requires frequently inverting large square matrices (100-200 rows/colums). I'm hitting the limits of machine precision so have started trying to use mpmath to do arbitrary precision matrix inversion but it is…
user2153813
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Why does plotting something with matplotlib change the first outcome of a numpy.linalg.inv inversion with complex entries and how to avoid it?

I was coding for a project of mine and found some strange nan values appearing in my code the first time I ran it, which disappeared when I ran the same line of code a second time. Searching for the reason took me some hours and I nailed it down to…
Frederix96
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How to check if a matrix is invertible in tensorflow?

In my Tensorflow graph, I would like to invert a matrix if it is invertible do something with it. If it is not invertible, the, I'd like to do something else. I could not find any way to check if the matrix is invertible in order to do something…
Joseph Budin
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Pandas find duplicates with reversed values between columns

What is the fastest way to find duplicates where value from Column A have been reversed with value from Column B? For example, if I have a DataFrame with : Column A Column B 0 C P 1 D …
ldoe
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