matching

Postgresql

生来就可爱ヽ(ⅴ<●) 提交于 2019-12-04 14:03:18
There are three separate approaches to pattern matching provided by PostgreSQL : the traditional SQL LIKE operator, the more recent SIMILAR TO operator (added in SQL:1999), and POSIX-style regular expressions. Aside from the basic "does this string match this pattern?" operators, functions are available to extract or replace matching substrings and to split a string at matching locations. Tip: If you have pattern matching needs that go beyond this, consider writing a user-defined function in Perl or Tcl. 9.7.1. LIKE stringLIKEpattern[ ESCAPEescape-character ]stringNOT LIKEpattern[ ESCAPEescape

When to use Rabin-Karp or KMP algorithms?

…衆ロ難τιáo~ 提交于 2019-12-04 08:19:27
问题 I have generated an string using the following alphabet. {A,C,G,T} . And my string contains more than 10000 characters. I'm searching the following patterns in it. ATGGA TGGAC CCGT I have asked to use a string matching algorithm which has O(m+n) running time. m = pattern length n = text length Both KMP and Rabin-Karp algorithms have this running time. What is the most suitable algorithm (between Rabin-Carp and KMP) in this situation? 回答1: When you want to search for multiple patterns,

mysql - Find page of result record in pagination

旧城冷巷雨未停 提交于 2019-12-04 06:02:51
imagine that we use pagination to split and display a mysql result like this, sorted on auto inceremental ID and date: SELECT name FROM members ORDER BY id DESC, date DESC LIMIT $start, $len we display that result and page navigation links below it using php. how we can find that record ID number x is in which page of that result so we set page number to that page and display that page and end-user do not need to click navigation and find it? First get total number of records. select count(*) as total from members; Find the number of the row member 'x' is found in the record list select count(

here i want to compare whether to image match with other or not…how to solve it?

这一生的挚爱 提交于 2019-12-04 05:51:56
问题 here is my code: function check i1=imread('cricketteam.jpg'); [y,x,d]=size(i1); m=imread('musfiq.jpg'); [y1,x1,d]=size(m); x2=1; y2=1; row_match=0; flag_y=0; cx=1; xc=1; xc1=1; counter=0; counter1=0; s_loop=x-x1; k=0; s_loop= s_loop+1; for i=1:y cx=xc; for j=cx:x disp(i) disp(j) counter1=counter1+1; if j==s_loop && row_match==0 break; end f=impixel(m,x2,y2); disp(f) ma=impixel(i1,j,i); disp(ma) d=[155 165 128]; if ma==d k=1; end if isequal(f,ma)==1 disp('Image Matched') if row_match == 0 xc

How does the Hopcroft-Karp algorithm work?

杀马特。学长 韩版系。学妹 提交于 2019-12-04 04:08:59
I am currently working on a project to pictorially explain the Hopcroft-Karp algorithm. I am using the pseudo-code from the Wikipedia article . I have also seen this algorithm implemented on Stack Overflow in Python This would do fantastically if only I didn't have to understand the algorithm completely to use it. My questions are as follows: What is the meaning of the Dist[] array in the pseudo-code, and how is the layering of the graph done in the Breadth-First-Search. I have a grasp on the workings of the DFS. Thanks in advance. The standard BFS creates layers such that nodes in successive

Matching inexact company names in Java

六眼飞鱼酱① 提交于 2019-12-04 03:12:53
I have a database of companies. My application receives data that references a company by name, but the name may not exactly match the value in the database. I need to match the incoming data to the company it refers to. For instance, my database might contain a company with name "A. B. Widgets & Co Ltd." while my incoming data might reference "AB Widgets Limited", "A.B. Widgets and Co", or "A B Widgets". Some words in the company name (A B Widgets) are more important for matching than others (Co, Ltd, Inc, etc). It's important to avoid false matches. The number of companies is small enough

How to save both matching and non-matching from grep

試著忘記壹切 提交于 2019-12-04 01:37:02
问题 I use grep very often and am familiar with it's ability to return matching lines (by default) and non-matching lines (using the -v parameter). However, I want to be able to grep a file once to separate matching and non-matching lines. If this is not possible, please let me know. I realize I could do this easily in perl or awk, but am curious if it is possible with grep. Thanks! 回答1: If it does NOT have to be grep - this is a single pass split based on a pattern -- pattern found > file1

Find minimum vertex Cover for bipartite graph given the maximum matching

筅森魡賤 提交于 2019-12-03 22:11:57
I seem to have found an algorithm but am having trouble understanding it, I was wondering if any of you knew the generic outline of the algorithm. Here is the link to the algorithm I found on page 2 http://www.cse.iitb.ac.in/~sundar/cs435/lecture23.pdf Luixo Algorithm is simple as that: Find unmatched vertex, mark it as not included in minimum vertex cover. Mark all matched neighbours of this vertex as included in minimum vertex cover. Treat all mates of vertexes from previous step as unmatched vertexes and repeat step 1. If recursion ended, repeat from step 1 (that is case of several

OpenCV - RobustMatcher using findHomography

好久不见. 提交于 2019-12-03 21:54:41
I've implement a Robust matcher found on the internet based on differents tests : symmetry test, Ratio Test and RANSAC test. It works well. I used then findHomography in order to have good matches. Here the code : RobustMatcher::RobustMatcher() : ratio(0.65f), refineF(true),confidence(0.99), distance(3.0) { detector = new cv::SurfFeatureDetector(400); //Better than ORB //detector = new cv::SiftFeatureDetector; //Better than ORB //extractor= new cv::OrbDescriptorExtractor(); //extractor= new cv::SiftDescriptorExtractor; extractor= new cv::SurfDescriptorExtractor; // matcher= new cv:

How to count the number of objects detected with Template Matching?

生来就可爱ヽ(ⅴ<●) 提交于 2019-12-03 21:40:43
I was reading the docs about template matching with opencv and python and in the last part about template matching with multiple objects, the code detect the 19 coins on the mario image but, is it possible to count the number of objects detected with some function on python like len() or any opencv method? Here is the code showed on the tutorial: http://docs.opencv.org/3.1.0/d4/dc6/tutorial_py_template_matching.html Template Matching Code: import cv2 import numpy as np from matplotlib import pyplot as plt img_rgb = cv2.imread('mario.png') img_gray = cv2.cvtColor(img_rgb, cv2.COLOR_BGR2GRAY)