inversion

How to manipulate strings in GO to reverse them?

筅森魡賤 提交于 2020-08-26 09:08:59
问题 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 so far I could not. The idea here is to generate 5 strings with random characters of sizes 100, 200, 300, 400 and 500 and then invert their characters. I was able to make C work with ease, but in GO, the language returns an error saying that it is

How to manipulate strings in GO to reverse them?

我是研究僧i 提交于 2020-08-26 09:07:17
问题 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 so far I could not. The idea here is to generate 5 strings with random characters of sizes 100, 200, 300, 400 and 500 and then invert their characters. I was able to make C work with ease, but in GO, the language returns an error saying that it is

Why Coq doesn't allow inversion, destruct, etc. when the goal is a Type?

流过昼夜 提交于 2020-01-10 19:32:28
问题 When refine ing 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 inversion on 'H : 0 > 0' *) Coq complained Error: Inversion would require case analysis on sort Type which is not allowed for inductive definition le However, since I do nothing with T , it shouldn't matter, ... or ? I got rid of the T like this, and

Why Coq doesn't allow inversion, destruct, etc. when the goal is a Type?

末鹿安然 提交于 2020-01-10 19:31:31
问题 When refine ing 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 inversion on 'H : 0 > 0' *) Coq complained Error: Inversion would require case analysis on sort Type which is not allowed for inductive definition le However, since I do nothing with T , it shouldn't matter, ... or ? I got rid of the T like this, and

How to invert colors of an image in pygame?

故事扮演 提交于 2019-12-23 07:56:39
问题 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 for now. I'm surprised that pygame doesn't have something like this built in! Thanks for your help! import pygame def invertImg(img): """Inverts the colors of a pygame Screen""" img.lock() for x in range(img.get_width()): for y in range(img.get

alternatives or speedups for mpmath matrix inversion

帅比萌擦擦* 提交于 2019-12-22 13:31:39
问题 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 very slow, even using gmpy . Inverting random matrices of size 20, 30, 60 at precision 30 (decimal) takes ~ 0.19, 0.60, and 4.61 seconds whereas the same operations in mathematica take 0.0084, 0.015, and 0.055 seconds. This is using python3 and mpmath

alternatives or speedups for mpmath matrix inversion

末鹿安然 提交于 2019-12-22 13:31:14
问题 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 very slow, even using gmpy . Inverting random matrices of size 20, 30, 60 at precision 30 (decimal) takes ~ 0.19, 0.60, and 4.61 seconds whereas the same operations in mathematica take 0.0084, 0.015, and 0.055 seconds. This is using python3 and mpmath

Flex: Inverting LinearAxis values

China☆狼群 提交于 2019-12-13 03:47:39
问题 I have a line chart that is updated every so and so seconds, similar to the one you see in Windows' Task Manager. The chart goes right-to-left, with the most recent data on the right, and going leftwards. How would I invert the values of the X axis so that the lowest value is on the right and the highest on the left? It's a LinearAxis. I tried making it a CategoryAxis and putting the numbers in manually, but that doesn't work the way it should (the labels are not aligned with the ticks). Or,

Javascript implementation of the inversion-counting with merge-sort algorithm

徘徊边缘 提交于 2019-12-10 23:09:08
问题 i am trying to implement the inversion-counting using merge sort algorithm in javascript. I found description and pseudo-code on this site. My implementation looks like this: var mergeAndCount, sortAndCount; /* the merging routine @param List1 the first list to be merged @param List2 the second list to be merged */ mergeAndCount = function(List1, List2) { var count, outputList; outputList = []; count = 0; while (List1.length > 0 || List2.length > 0) { outputList.push(Math.min(List1[0], List2

TypeError: slice indices must be integers or None or have an __index__ method

泪湿孤枕 提交于 2019-12-10 05:00:59
问题 When running the code in IDLE gives the following error: Traceback (most recent call last): File "C:/Python34/inversion3.py", line 44, in <module> nInversions.inversionMergeSort(m) File "C:/Python34/inversion3.py", line 16, in inversionMergeSort left = m[0:half] TypeError: slice indices must be integers or None or have an __index__ method CODE:- from collections import deque m = [] f = open("IntegerArray.txt") for line in f: m.append(int(line)) class InversionCount: def __init__(self, n):