L********1
发帖数: 710 | 1 看了几个review，好像polygonal rifling是CZ82的一个亮点，Google了一下，用同样
技术的还有HK，Glock，Kahr，都没有刻意宣传这个polygonal rifling的应用。是不是
CZ82没啥别的好宣传了？ |
|
A****r
发帖数: 2746 | 2 polygonal rifling不是什么新技术，但CZ82的polygonal rifling和其他的比，太光滑
了，于是很多人认为是打得太多膛线都磨没了。CZ这么强调可能是为了防止大家退货吧
。我觉得CZ82的主要优点是左右手均可操作，便宜，以及C&R eligible.他可能是C&R能
搞到的最现代的手枪了吧。 |
|
n*****r
发帖数: 2447 | 3 It is a very stupid question -_____-, but I still want to know how.
I have the DEM file, and now i just need a small piece of it. I have a
polygon(shapefile), which is the boundary of a watershed, and now I want to
cut the DEM file using this polygon. But Arc just does not allow me to do
that. I used the Analysis Tools--Extract--Clip. But I can not input the DEM
file...Why?
I am not a master of GIS, just need to use the DEM file to finish my
hydrologic analysis.....
Thank you.... |
|
a*******8
发帖数: 32 | 4 可考虑对多边形图层作Voronoi Diagram, 所得结果除了Voronoi polygons外，还有一
个distance raster (假设取名为DisRaster). 每个居民地址点在DisRaster上所对应的
像元值就是你要算的最短距离。计算200点只需3-4秒。17，000个polygon也不会花太多
时间。我在ESRI Scripts 看到这个extension, 可以下载试试。有问题欢迎来信交流。
http://arcscripts.esri.com/details.asp?dbid=15481 |
|
n*****r
发帖数: 2447 | 5 polyline shapefile 有7000多个record，用toolbox里面的feature to polygon转成
polygon之后，变成只有4000多record，而且polyline的attribute table里面所有的
field都没有了。怎样才能保有原来polyline的attribute呢？因为INDEX也没有了所有
没办法和原来的table join。
我试过用command，还是没有办法保存原来的attribute啊，这是怎么回事呢？ |
|
b***m
发帖数: 22 | 6 I am working on 2D mesh video object coding(proposed in MPEG-4). The shape of
the object is represented with a binary alpha plane(in or out of the object,
black or white).
And, I am now thinking using a polygon to approximate the shape. Simply, that
means to put some nodes on the boundary of the object, and link the nodes one
by one to form a polygon.
Do you guys have some ideas about how to do this job? And do you know where to
get free share source code for it?
Thanks a lot! |
|
g**********8
发帖数: 273 | 7 请问 Polygon Northwest建造的房子质量怎么样？ |
|
l****j
发帖数: 114 | 8 我刚在北面买下了个他们的新townhouse，房子质量还不知道，还没开始住，但服务是
非常的好。我很怕买房过程中乱七八糟的糟心事，和他们交易的过程中一点不愉快都没
遇到，用的他们自己的贷款公司，整个过程非常轻松愉悦。我从打算买房，一直在家居
版学习，好像像我这样轻松买房的（不是指钱上）很不多。
我觉得Polygon这样大规模买地建townhome,condo的公司，质量肯定不会是最好的，他
们的市场定位摆在那里。如果图省钱省心，房子不是买来住一辈子的，将来经济宽松了
有可能再换的，我还是满推荐的。 |
|
|
d*****e
发帖数: 270 | 10 这是我的代码，但是结果是把pOutFClass所有的pologon都转成GRID了，怎么搞？
我只想要我选择的，在SelectionSet里面polygon。
‘从FeatureClass中得到SelectionSet
Set pSelectionSet = pOutFClass.Select(pSpatialFilter,
esriSelectionTypeHybrid, esriSelectionOptionNormal, pWS)
Dim pFCDescriptor As IFeatureClassDescriptor
Set pFCDescriptor = New FeatureClassDescriptor
pFCDescriptor.CreateFromSelectionSet pSelectionSet, Nothing, "GRIDCODE
"
Dim pFCExtract As IFeatureClass
Set p |
|
k**a
发帖数: 1181 | 11 有若干居民地址，要计算每个地址到最近的某区域（例如水域，森林，农田之类）的边
界的最短距离。我用MapInfo里的distance calculator算，不知道是设得不对还是怎么
样，反正非常慢，一小时算得还不到50%，不到2000个居民地址，和17，000多个
polygon，我想一定是出错了。懂行的同学能不能指点一下这种情况应该怎么计算。
多谢了！ |
|
t********r
发帖数: 4908 | 12 如果不需要特别精确,可以将polygon convert to point (using vertesis)计算每
个点到target的距离,并且取最小值
arctoolbox就有这些工具,不用自己编程 |
|
w*m
发帖数: 1806 | 13 Great. 我当时没有具体的找，希望你这个方法节省很多时间。
我当时的方法是这样的，
Create a buffer zone near river(or other polygons, whatever),then convert it
to raster image(sorry, I'm not sure it is nessary or not, check it by
yourself). Finally, use your point coordination(x,y) to get the value of
that buffer zone. That value is the shortest distance you're looking for.
bufferzone划分的越细，结果越准确。 |
|
p********1
发帖数: 1011 | 14 arcView 9.3版本, create thiessen polygon的步骤是什么？用哪个tool? |
|
p********1
发帖数: 1011 | 15 建thiessen polygon然后regression，是不是就是quadrat analysis的一种方法？
还是quadrat analysis用的根本就是不同方法？
请指教。 |
|
l*******1
发帖数: 113 | 16 for a n-sided polygon, starting from any vertex, whats the expected time
until all the other vertices are visited, if we randomly go to the two
neighboring vertices with equal probability?
thanks |
|
p********1
发帖数: 1011 | 17 研究中遇到的问题，需要在arcGIS中给一个城市建grids，建的方法是以每个交叉路口
为中心、以每个block的中点为边界，建thiessen polygons。
求高手，怎么做？ |
|
B********t
发帖数: 147 | 18 正在学OOD, 大家看看有什么问题：
class Polygon
{
public:
char type;
virtual bool requestResource();
virtual bool acceptRequest(int num);
virtual ~Polygon();
};
class Resource : public Polygon
{
pthread_mutex_t lock;
int numOfResources;
Polygon *neighbour;
public:
Resource();
bool acceptRequest(int num)
{
//lock
//if no resource, unlock, return false
//otherwise, assign, unlock, return true
}
Polygon *nextNeighbour();
};
class Base : publi... 阅读全帖 |
|
l*******1
发帖数: 16217 | 19 说了，中国的PI值在中古时代最准
https://en.wikipedia.org/wiki/Pi
Antiquity
The best known approximations to π dating before the Common Era were
accurate to two decimal places; this was improved upon in Chinese
mathematics in particular by the mid first millennium, to an accuracy of
seven decimal places. After this, no further progress was made until the
late medieval period.
In ancient China, values for π included 3.1547 (around 1 AD), √10 (100 AD,
approximately 3.1623), and
142
/
45
(3rd century, approximatel... 阅读全帖 |
|
d*******o
发帖数: 493 | 20 丫丫付包子最及时了，求长期包养。
library(gridBase)
library(lattice)
panel.piechart <-
function(x, y, labels = as.character(y),
edges = 200, radius = 0.8, clockwise = FALSE,
init.angle = if(clockwise) 90 else 0,
density = NULL, angle = 45,
col = superpose.polygon$col,
border = superpose.polygon$border,
lty = superpose.polygon$lty, ...)
{
stopifnot(require("gridBase"))
superpose.polygon <- trellis.par.get("superpose.polygon"... 阅读全帖 |
|
i****a
发帖数: 36252 | 21 in office so can't listen to the narrative
but if the polygons are small enough, isn't it the same as dot cloud?
and if the polygons are really really small, it effectively becomes a
dot
currently the polygon graphics is limited by the time it takes to model
the objects, and the processing power of the graphic cards, NOT by the
size of the polygons
I don't see how this dot cloud could change that.
Unlim
建模
效果 |
|
z****e
发帖数: 54598 | 22 Mathematics
While he is often regarded as a designer of mechanical devices, Archimedes
also made contributions to the field of mathematics. Plutarch wrote: "He
placed his whole affection and ambition in those purer speculations where
there can be no reference to the vulgar needs of life."[42]
Archimedes used the method of exhaustion to approximate the value of pi.
Archimedes was able to use infinitesimals in a way that is similar to modern
integral calculus. Through proof by contradiction (reduc... 阅读全帖 |
|
l*******G
发帖数: 1191 | 23 Thanks, sounds cool, walk through all edges, any edge that ever bounds two
or more element is an interior edge, then remove that edge. Rest of edges
make up the boundary . Start from any one of the remaining edge and walk
along to original point to find one polygon. Continue if still have edges
not identified. There is a problem if two polygons kiss each other by
sharing a node. The way to walk back to original point is not unique. In
that case, one finds the shared point will be walked... 阅读全帖 |
|
l*******G
发帖数: 1191 | 24 Thanks, sounds cool, walk through all edges, any edge that ever bounds two
or more element is an interior edge, then remove that edge. Rest of edges
make up the boundary . Start from any one of the remaining edge and walk
along to original point to find one polygon. Continue if still have edges
not identified. There is a problem if two polygons kiss each other by
sharing a node. The way to walk back to original point is not unique. In
that case, one finds the shared point will be walked... 阅读全帖 |
|
a*********3
发帖数: 660 | 25 定义 definition变量 variable面积 area直径 diameter半径 radius公式 formula
单价 unit price范围 range/scope/extent集合 set法则 principle本金 principal利
率 interest rate利息 interest单利 simple interest复利 compound interest正数
positive number负数 negative number解析式 analytic expression分类讨论
classified discussion性质 nature （不是很确定）奇函数 odd function偶函数
even function对称 symmetric坐标原点 origin单调性 monotonicity（不是很确定）
任意 random周期性 periodic 有界性 boundedness 数学 mathematics, maths(BrE)
, math(AmE) 公理 axiom 定理 theorem 计算 calculation 运算 operat... 阅读全帖 |
|
t******l
发帖数: 10908 | 26 OK, 我成功的稳定地能做 6 个，但是用了一个更复杂的 cheat。
首先我用前面做 5 个的 cheat，但是连续三次全失败了。于是我默念了三遍 Piaget
的 object-permanence on motion objects 以后，观察了以后发现用一个新的 cheat
。这个 cheat 比较复杂，详细这么说：
首先我不仅仅记住点，而且记住前后两点之间的连线，想象成一个 motion object w/
path hided。成为一个 open-end polygon w/ construction order. (chunking?)
然后我就在新点出来的时候，不短 rolling refresh 那个 open-end polygon w/
construction order.
在最后一个点出来以后，我最后一遍 forward refresh 那个 “open-end polygon w/
construction order”（如果不确信的话，refresh 两遍好了）。然后 reverse click
on the vertexes。（之前我漏了这先 forwa... 阅读全帖 |
|
n********a
发帖数: 68 | 27 Check constraint can only be enforced on a table.
And you can define constraints on the leaf-level scalar attributes of a column
object.
However, in your case, Polygons.Lines is a table collection of objects.
I don't think you declare a simple check constraint.
Use trigger to iterate each member of Polygons.Lines and check for error
conditions
create or replace trigger trig_polygons
after insert or update on Polygons
for each row
begin
for i in 1..:new.Lines.count loop
if :new.Lines(i).SP. |
|
H*M
发帖数: 1268 | 28 You are given a convex polygon and an additional point. You know the x and y
co-ordinates of all vertices of the polygon and the point. Find if the poin
t is one of the vertices of the polygon in O(log N) time.
lgn?? |
|
s*******1
发帖数: 146 | 29 First, you should have a US map (Polygon shapefile),
then, import your point data into ArcGIS, create a point shapefile,
then, clip the point shapefile by the US polygon shapefile,
you get a a clipped US polygon shapefile.In this map, the points in US have
been merged into the US map. Go to the dbf file associated with the clipped
file, you get the points in the US. You can import data into Excel or SAS
to do future analysis. |
|
s*******1
发帖数: 146 | 30 First, you should have a US map (Polygon shapefile),
then, import your point data into ArcGIS, create a point shapefile,
then, clip the point shapefile by the US polygon shapefile,
you get a a clipped US polygon shapefile.In this map, the points in US have
been merged into the US map. Go to the dbf file associated with the clipped
file, you get the points in the US. You can import data into Excel or SAS
to do future analysis. |
|
D**u
发帖数: 204 | 31 This method essentially generates a solution from an odd-numbered polygon,
rather than from an even-numbered polygon. Following this line, we can
generate a closed curve from any convex odd-numbered polygon A_1, A_2, ..., A_
(2n+1).
The idea is: centered at point A_k with radius x_k we draw a curve which has
the two end points on the line A_kA_(k+n) and A_kA_(k+n+1); then with radius y
_k we draw another curve which has two end points on the opposite
direction of A_kA_(k+n) and A_kA_(k+n+1).
To |
|
D**u
发帖数: 204 | 32 【 以下文字转载自 Quant 讨论区 】
发信人: DuGu (火工头陀), 信区: Quant
标 题: 来一道题(由 BT question 而想)
发信站: BBS 未名空间站 (Sat Mar 6 14:46:26 2010, 美东)
On a 2-dim plane, F is a (real number valued) function on each polygon area
P. We also know that if P is the union of 2 disjoint polygon areas P1 and P2
, then
F(P) = F(P1) + F(P2).
Question: if for every rectangle D (no need to be parallel to x-y axis) we
have F(D) = 0, does that imply that F(P) = 0 for every polygon area P? |
|
D**u
发帖数: 204 | 33 On a 2-dim plane, F is a (real number valued) function on each polygon region
P. We also know that if P is the union of 2 disjoint polygon regions P1 and P2
, then
F(P) = F(P1) + F(P2).
Question: if for every rectangle D (no need to be parallel to x-y axis) we
have F(D) = 0, does that imply that F(P) = 0 for every polygon region P? |
|
c****s
发帖数: 5892 | 34 转眼来加己十年多了，一路走来，有失望，有彷徨，但经过自己的努力奋斗，更多的 是收获。在这里，我把移民十年的大事记录下来，与新老移民朋友们共亨。
2000年，六月登陆温哥华，只带了一万一千加币过来，一边试着找专业工作，一边在工厂 打工。两个月后买了自己的第一辆二手车-Toyota Cressida
2001年，当时经济非常低迷，眼看找专业工作无望，便跑去BCIT读当时很热的专业--会计，先part time，九月份转full time，刚开学就赶上911，因课程太累，一个半月后quit掉。当年11月份，进入建筑行业，在一个很小的建筑装修公司做helper
2002年，5月份跳槽到另一家装修公司，凭借英语好的优势很快做了forman，并亲子动手学习与flooring有关的安装技术
2003年，2月份成立自己的Contracting公司，当时建筑业刚刚开始发热，凭 Vancouver Sun 报纸广告拿到我自己公司成立后的 第一个subcontract，位于Vancouver downtown西端38层高的hirise-Classico。
当年7月头脑发热，把旧车换成全新的Honda CRV... 阅读全帖 |
|
发帖数: 1 | 35 The distance to a point is a convex function.
Sum of convex functions is a convex function.
Within the confine of a convex polygon,
the max of a convex function lies on a vertex.
On vertex A of polygon ABCD, the sum of distances is
S=AB+DA+AC.
AC
S<(AB+BC+CD+DA) + (AB+DA-BC-CD)/2 |
|
d**e
发帖数: 6098 | 36 ☆─────────────────────────────────────☆
travelodge (travelodge) 于 (Fri Aug 31 00:46:34 2012, 美东) 提到:
总觉得山寨淘宝的research scientist很鸡肋， 工资跟sde一样，但基本不
发paper,
这样怎么来评定该不该升级。 不发paper又不经常写code那就等于没法跳槽，万一被裁
员别家的research scientist还是看paper的吧。
至于山寨百度的SDE(T4), 又担心他们家高手如云， 很难升级， 会不会做万年sde(最多
升到5）
钱上其实账目上差不多， 扣掉免税州的低房价， 不过淘宝少了很多福利
对于fresh phd来说
RSII: 125k + 40k sign-on /2 + 55k RSU / 4 = 158.75K
SDE 127k + 15% bonus + 160 RSU/4 = 170K
有没有过来人给点建议。。。。
面经，记不清了
山寨淘宝/京东
onsite有个job talk,
然后有五六轮聊天面试吧，题目... 阅读全帖 |
|
c*******2
发帖数: 60 | 37 随机选个方向过这点做射线，计算射线于polygon的多少条边相交，奇数在里面偶数在
外面。注意不能是polygon的顶点，否则另选射线，因为随机性，过顶点的概率几乎是0 |
|
W*********y
发帖数: 481 | 38 平面上一个polygon，用point的数组表示，顺序链接而成。
一条平面线段，用两个point表示。
求这条线段包含在polygon interior内部的所有segment部分。 注意可能有多段
segment的情况。
看下图的例子，输入线段为A B 坐标，应该返回 [[C,D], [E,F]] 的坐标
http://tinyurl.com/lbcmxrp |
|
a*****g
发帖数: 19398 | 39 Fla. school incorporates song and dance into math, reading
http://www.news-journalonline.com/article/20140410/NEWS/1404199
概要翻译：
美国佛罗里达一所小学的五年级学生通过歌曲和舞蹈学数学概念。
这个项目是从前的一位老师开发的，
里面包括诸如“八边形或者其他多边形里面有多少个边”之类的问题。
Students at an elementary school in Florida are using song and dance to
remember key math and reading concepts. Students use the program --
developed by a former teacher -- to learn concepts, including how many sides
are in an octagon and other polygons. "It's a great way for the children to... 阅读全帖 |
|
a*****g
发帖数: 19398 | 40 Fla. school incorporates song and dance into math, reading
http://www.news-journalonline.com/article/20140410/NEWS/1404199
概要翻译：
美国佛罗里达一所小学的五年级学生通过歌曲和舞蹈学数学概念。
这个项目是从前的一位老师开发的，
里面包括诸如“八边形或者其他多边形里面有多少个边”之类的问题。
Students at an elementary school in Florida are using song and dance to
remember key math and reading concepts. Students use the program --
developed by a former teacher -- to learn concepts, including how many sides
are in an octagon and other polygons. "It's a great way for the children to... 阅读全帖 |
|
t******l
发帖数: 10908 | 41 我刚才联想到 F-117 vs F-22 / B-2 的壳子，突然领悟到 “球用数学” 虽然
不算 “石器时代数学”，但基本是 “肉算时代数学”。
我觉得首先是分析一下 “球用数学” vs “实用数学” 的最大差别是在啥地方。
我觉得 “球用数学” 本质是追求复杂问题也能把解写成 closed form。写不出
closed form 就霸王硬上弓，上各种奇奇怪怪的符号，装鼻也要装出个 closed
form。
而 “实用数学” 只研究简单基本问题写成 closed form（图灵机也费电不是，
也得考虑低碳环保，而且慢到花儿也谢了这也不成）。对于复杂实际问题，
“实用数学” 更热衷于利用 mathematical structure 横切竖砍、庖丁解牛，
把问题降解成简单基本的问题。而这过程就不再热衷于 closed form，只要
能图灵电算就足够了。
这个最最生动的例子，就是 F-117 vs F-22 / B-2 的壳子：
“球用数学” 的 closed form，撑死也只能算 F-117 这种古代 polygon 壳子
的飞机。
而计算 F-22 / B-2 的壳子，再咋地也... 阅读全帖 |
|
t******l
发帖数: 10908 | 42 但这可能有引发了另一个怀疑。具体这么说：
The shape of open-end polygon 就是一个 spatial encoding of temporal info (
phonological order of the vertex)。所以有争议的说，这个有可能是用 visual-
spatial sketchpad 的 shape memory，通过 encoding temporal info，至少是
partially
assist phonological order。
而这个容易被主观 suppress，是因为这个 polygon encoding 更 complex，not that
easy to learn。
所以，上面的 digital span，也很难知道到底是 implicitly articulate loop 呢？
还是大脑自我训练出了更新版的 encoding temporal，可以利用 visual-spatial
sketchpad 来 assist articulate loop，或者干脆是两者兼而有之。
D
100%
I
relen... 阅读全帖 |
|
a***a
发帖数: 8941 | 43 HKs have polygonal rifling
both my P30 and P7 have polygonal rifling |
|
l******n
发帖数: 11737 | 44 EA首席營運官Peter Moore接受polygon訪問時被問有說EA 對主機廠商施加強壓要他們
實行DRM, 限二手時
Peter Moore強烈地否認有關指控
Moore: "這絕對不是事實. 身為EA首席營運官的我可告訴你, EA沒有對主機廠商施加強
壓去操控2手販賣. 我一向是2手遊戲的擁護者. 我喜歡這生態系統. 我喜歡它讓價錢在
過去8年維持合理水平的事實. 我喜歡某人買了實體遊戲後可看到其中有資產價值的事
實. 這亦讓 GameStop 保持活躍, 而他們是我們重要的推行營銷伙伴"
"我參與了所有和主機廠商間的對話, EA從沒要求廠商必須為主機設立機制, 讓我們能
控制, 甚至禁止 (2手的販賣). 這(指控)絕對不是事實"
http://www.polygon.com/2013/6/11 ... -drm-and-used-games |
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l***8
发帖数: 2233 | 45 此前，官方宣布《P.T.》下架PSN后，有网友发现该游戏仍旧可以通过下载获取，
只要玩家将其放入过PS4“内容库（PS4 Library）”，但是今日Polygon网站的编辑
Russ Frushtick和多名网友证实，《P.T.》目前已完全无法下载，这意味着新寂静岭《
P.T.》彻底跟我们说再见了。看来如果你还想要玩到这款游戏的话，只能通过eBay高价
（1000欧元约合人民币7000元）购买装有“P.T.”的PS4了。
凭借着带有特色的诡异剧情和恐怖设定，新寂静岭《P.T.》从诞生之初便吸引了很多玩
家的关注，然而可惜的是，小岛和Konami的决裂直接导致了《P.T.》的流产。尽管网友
自发的在网上发起了“挽救《新寂静岭》”的请愿活动，并吸引了将近10万人参与，但
此举看似并没有打动Konami的铁石心肠。今日，Polygon网站的编辑Russ Frushtick在
twitter上表示《P.T.》目前已无法下载，随后许多网友同样证实了这一点。
★ 发自iPhone App: ChineseWeb 8.2.2 |
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r******y
发帖数: 3838 | 46 http://www.macrumors.com/2011/01/14/ios-4-3-beta-hints-at-openc
devices/
When it comes to the graphics performance on Apple's iOS devices, the
company has been sticking with the
powerful POWERVR SGX535 GPU from Imagination Technologies for quite some
time, introducing it on the
iPhone 3GS and carrying it through into the company's own A4 system-on-chip
designs for the brains of the
iPad and iPhone 4. But hints included in the new iOS 4.3 beta seeded to
developers earlier this week indicate
that ... 阅读全帖 |
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r******y
发帖数: 3838 | 47 【 以下文字转载自 Apple 讨论区 】
发信人: rhapsody ( input type=\"button\" value=), 信区: Apple
标 题: iOS 4.3 Beta Hints at OpenCL-Capable SGX543 GPU in Future Devices
发信站: BBS 未名空间站 (Tue Mar 8 19:46:52 2011, 美东)
http://www.macrumors.com/2011/01/14/ios-4-3-beta-hints-at-openc
devices/
When it comes to the graphics performance on Apple's iOS devices, the
company has been sticking with the
powerful POWERVR SGX535 GPU from Imagination Technologies for quite some
time, introducing it on the
iPhone 3GS and carrying ... 阅读全帖 |
|
f***e
发帖数: 17 | 48 现在我有type point and type line, table polygons(多边形)如下：
create or replace type Point as object(
X float,
Y float
);
/
create or replace type Line as object(
SP point, -- start point
EP point -- end point
);
/
create or replace type LineTableType as
table of Line;
/
create table Polygons(
PID integer,
Lines LineTableType
)
nested table Lines store as LinesTable;
ÏÖÔÚ因为所有µÄµã¶¼&
Ocirc;ÚµÚ1象限£ |
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j******o
发帖数: 82 | 49 It depends. the performance of filling a polygon is better than that of
Java2D with a line stroke > 1. If it's just a horizontal or vertical line
you can use the polygon approach with simple math, although it is not
hard for a line with any slope either.
g.drawPolygon() will respect the antialiasing hint. |
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