intersect

Ray intersection with 3D quads in XNA?

由 会有一股神秘感。 提交于 2020-01-11 09:43:09
问题 So I have successfully made a ray the represents the mouse unprojected into the world, and now I need to check if that ray can intersect with a quad object, here is the code I use to get the ray: public Ray GetMouseRay() { Vector2 mousePosition = new Vector2(cursor.getX(), cursor.getY()); Vector3 nearPoint = new Vector3(mousePosition, 0); Vector3 farPoint = new Vector3(mousePosition, 1); nearPoint = viewport.Unproject(nearPoint, projectionMatrix, viewMatrix, Matrix.Identity); farPoint =

对mysql使用索引的误解 – 小松博客

由 自古美人都是妖i 提交于 2020-01-07 05:39:08
【推荐】2019 Java 开发者跳槽指南.pdf(吐血整理) >>> 之前我一直以为mysql一个查询中只能使用一个索引，网上的资料有这个说的，而且我也以为是这样的，结果今天发现错了 主要是在验证只使用一个索引的时候发现，key中显示了两个索引字段，type中显示index_merge 如图 如果按照之前的理解只使用个索引，那就有问题了，那为什么有人会说只使用一个索引 答案在这里版本问题 MySQL5.0之前，一个表一次只能使用一个索引，无法同时使用多个索引分别进行条件扫描，但是从5.1开始，引入了 index merge 优化技术，对同一个表可以使用多个索引分别进行条件扫描 不能在相信百度里的资料了，查官方文档 官方文档: http://dev.mysql.com/doc/refman/5.7/en/index-merge-optimization.html The Index Merge method is used to retrieve rows with several range scans and to merge their results into one. The merge can produce unions, intersections, or unions-of-intersections of its underlying scans. This

Compare two vectors of numbers based on threshold of tolerance (±) of 0.5

由 浪尽此生 提交于 2020-01-05 04:22:07
问题 I have two vectors g and h . I want to compare the numbers in these two vectors and find out whether there are any common elements between them. But the common elements do not have to be exactly the same and can be within a range of (-0.5, +0.5) . Therefore, g±0.5 is being compared with h±0.5 . g <- c(0.5, 5956.3, 38, 22.666, 590.3, 21.992, 9.3) h <- c(0.7, 99.2, 39, 30, 21.68, 9.4, 22.333, 0.001, 0.000222, 9.999) As an example, in the two vectors above, 0.5 from g and 0.7 from h match

how to convert an sqllite statement from '=' to MATCH instead

由 ≯℡__Kan透↙ 提交于 2019-12-24 15:01:47
问题 I'm trying to create a dbase solution for email threading. When I receive an email.. I want to know if this email belongs to an existing thread. So I match the subject ie subject = 'cool bro' matches 're: cool bro' and i also want to match the sender and receiver pair ie (sender = 'A@gmail.com' and receiver = 'B@gmail.com') OR (sender ='B@gmail.com' and receiver = 'A@gmail.com') for those exact cases.. this query worked fine (see more details here): (SELECT COUNT(search_email.threadID) FROM

Cannot open the connection in raster R

由 你。 提交于 2019-12-24 07:18:18
问题 I used these functions several times, and they were working perfect, nothing wrong with my input data!! m<-raster::intersect(raster,shapefile) or n<-crop(raster, extent(shapefile)) I have to do this operation for a large set of data. Therefore, I tried to increase the speed of R by using multicore . I did use multicore.tabulate.intersect function from here However, nothing works for me. Then, whenever I run intersect or crop function I got this error: m<-raster::intersect(raster,shapefile)

python intersect of dict items

由 こ雲淡風輕ζ 提交于 2019-12-24 02:56:22
问题 ok another python question... I have a dict: aDict[1] = '3,4,5,6,7,8' aDict[5] = '5,6,7,8,9,10,11,12' aDict[n] = '5,6,77,88' n could be any limit but the keys are not in sequence. How do I extract the intersect of the csv'd items? So in this case the answer would be '5,6'. Thanks 回答1: from functools import reduce # if Python 3 reduce(lambda x, y: x.intersection(y), (set(x.split(',')) for x in aDict.values())) 回答2: First of all, you need to convert these to real lists. l1 = '3,4,5,6,7,8'.split

intersect cassandra rows

由 瘦欲@ 提交于 2019-12-24 01:31:51
问题 We have cassandra column family. each row have multiple columns. columns have name, but value is empty. if we have 5-10 row keys, how we can find column names that appear in all of these keys. e.g. row1: php, programming, accounting row2: php, bookkeeping, accounting row3: php, accounting must return: result: php, accounting note we can not easily load whole row into the memory, because it may contain 1M+ columns solution not need to be fast. 回答1: In order to do intersection of several rows,

Opposite of intersect in groovy collections

由 老子叫甜甜 提交于 2019-12-23 06:49:10
问题 what would be the opposite of intersect in groovy collections? 回答1: You probably want to combine both the answers from @Andre and @denis I think what you want is the union and then subtract the intersection from this def a = [1,2,3,4,5] def b = [2,3,4] assert [1,5] == ( a + b ) - a.intersect( b ) The solution given by denis would depend on whether you do def opposite = leftCollection-rightCollection // [1,5] or def opposite = rightCollection-leftCollection // [] which I don't think you wanted

Opposite of intersect in groovy collections

由 一世执手 提交于 2019-12-23 06:49:01
问题 what would be the opposite of intersect in groovy collections? 回答1: You probably want to combine both the answers from @Andre and @denis I think what you want is the union and then subtract the intersection from this def a = [1,2,3,4,5] def b = [2,3,4] assert [1,5] == ( a + b ) - a.intersect( b ) The solution given by denis would depend on whether you do def opposite = leftCollection-rightCollection // [1,5] or def opposite = rightCollection-leftCollection // [] which I don't think you wanted

DELETE WITH INTERSECT

由 て烟熏妆下的殇ゞ 提交于 2019-12-22 05:22:10
问题 I have two tables with the same number of columns with no primary keys (I know, this is not my fault). Now I need to delete all rows from table A that exists in table B (they are equal, each one with 30 columns). The most immediate way I thought is to do a INNER JOIN and solve my problem. But, write conditions for all columns (worrying about NULL ) is not elegant (maybe cause my tables are not elegant either). I want to use INTERSECT . I am not knowing how to do it? This is my first question:
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