m******t
发帖数: 273 | 1 【 以下文字转载自 Quant 讨论区 】
发信人: myregmit (myregmit), 信区: Quant
标 题: how to do data fitting to find distribution
发信站: BBS 未名空间站 (Sat Mar 15 11:02:05 2014, 美东)
Hi,
I need to do data fitting to find the distribution of a given data.
I need to find the pdf funtion of the distribution.
I can use data fitting functions in matlab and python.
It looks like a truncated gamma.
But, how to find the paramters of the distribution ?
What if the data cannot fit the truncated gamma well ?
The QQ-plot (qunatile-qua... 阅读全帖 |
|
m******t
发帖数: 273 | 2 Hi,
I need to do data fitting to find the distribution of a given data.
I need to find the pdf funtion of the distribution.
I can use data fitting functions in matlab and python.
It looks like a truncated gamma.
But, how to find the paramters of the distribution ?
What if the data cannot fit the truncated gamma well ?
The QQ-plot (qunatile-quantile) show that it is not a good fit for truncated
gamma.
How to find the distribution parameters such as alpha (shape), beta (scale)
for the truncated g... 阅读全帖 |
|
a********e
发帖数: 78 | 3 谢谢解释，我可不可以这样理解：
按照这样的程序，
simulate x from N(mu,sigma^2)
let A=x if x in [a,b]
then A follows truncated N(mu,sigma^2) in [a,b]
假设x 得到3000个点，truncate后得到2800个点， 对这2800个点用histogram 求出PDF
，但这个PDF 是truncated normal distribution的pdf。 我要基于这个truncated PDF
去估计A。 |
|
m******t
发帖数: 273 | 4 【 以下文字转载自 Quant 讨论区 】
发信人: myregmit (myregmit), 信区: Quant
标 题: how to do data fitting to find distribution
发信站: BBS 未名空间站 (Sat Mar 15 11:02:05 2014, 美东)
Hi,
I need to do data fitting to find the distribution of a given data.
I need to find the pdf funtion of the distribution.
I can use data fitting functions in matlab and python.
It looks like a truncated gamma.
But, how to find the paramters of the distribution ?
What if the data cannot fit the truncated gamma well ?
The QQ-plot (qunatile-qua... 阅读全帖 |
|
N*****7
发帖数: 1899 | 5 If A is 4.02 and B is 3.25,
不需要"bring 4.02 to 4.0 and 3.25 to 3.5".
Truncation 是指 差0.48以上（不是0.50）， rating implied game difference
〉=12 时， 用0.48代替rating 差
4.02 vs 3.25， 差 0.77， bring the difference to 0.48 when
computing adjustment. (pls refer to #105）
如果比赛成绩 6：1， 6：0， 局差（DG） 11， 局差折合分（DGS） 0.44
0.44 - 0.48 = -0.04， 除二 Adj = -0.02.
代入原始算法 A 4.00， B 3.27； 这和不用truncation 的原始算法结果差很大。
kennyD 再除二： Adj = -0.01; A 4.01， B 3.26；
blacklodoss 再除三 （类似ACC的三次平均）： 四舍五入后 A 4.01， B 3.26；
如果比赛成绩 6：3， 6：3， 局差（DG） ... 阅读全帖 |
|
l******g
发帖数: 1623 | 6 谢谢你的回复.
4度下过夜就truncated的蛋白是从CHO细胞里面表达出来的,分泌到细胞外面,纯化后大
部分是truncated,小部分是intact的. 放过夜intact的就没有了. 这个cell line如果
培养超过3天,基本上培养基里面intact的就非常少了(我估计是因为pH下降, 酶活性提
高的缘故). 后来才用E.coli来表达,形成包含体还是比较稳定的,只有作western才能看
到truncated. 在高pH下复性, 拿到的都是intact的.
如果合成一段多肽包含cleavage site, 和我的蛋白混一起,如果多肽能被降解,是不是
说明有其他protease存在? 我在药厂, 本来是要把这蛋白作个therapeutical 药物的,
现在希望不大, 上头不太可能同意花时间作结晶什么的. |
|
l**********1
发帖数: 5204 | 7 De rien.
plus this one:
Shioda N et al. (2012)
Expression of a Truncated Form of the Endoplasmic Reticulum Chaperone
Protein, σ1 Receptor, Promotes Mitochondrial Energy Depletion and Apoptosis
JBC 287: 23318-31.
Abstract
The σ1 receptor (σ(1)R) regulates endoplasmic reticulum (ER)/mitochondrial
interorganellar Ca(2+) mobilization through the inositol 1,4,5-
trisphosphate receptor (IP(3)R). Here, we observed that expression of a
novel splice variant of σ(1)R, termed short form σ(1)R (σ(1)SR), has... 阅读全帖 |
|
e****s
发帖数: 1125 | 8 Your title is really confusing.
This could be very challenging. Because the truncated forms, especially
those with similar size to the full-length, behave very similar to full-
length protein. If most of your truncated is smaller than half of the full-
length, then it is doable. Gel filtration may helps to remove those big
truncated ones. You can also try those traditional columns, such as ion-
exchanged or hydrophobic columns.
Amacon's concentrator was not designed to do this.
I will suggest to... 阅读全帖 |
|
l***i
发帖数: 36 | 9 We already know there is a protein A have full length and truncated two
isoforms. The full length isoform shares the same sequence as truncated one.
How could I generate antibody that can only recognize truncated isoform in
flow or immune fluorecent staining. Thanks. |
|
f********8
发帖数: 5601 | 10 The difference is actually Censoring versus Truncation. Censoring means
corner solutions, the corresponding latent varialbes are negative.
Truncation simply means missing data, no observations are available, so
people put 0 when they collect data. Tobit is suitable for censoring, not
truncation. |
|
m******t
发帖数: 273 | 11 Yes, I have only mean and std. dev.
I only need to find shape, scale. If we can also find location, it will be
better.
I have a group of data mean and std. dev. It means that each data point in
the given set is a mean and std. dev., which are calculated from a truncated
gamma distribution.
Each point may have a different truncated gamma distribution, which has the
same truncated values.
They may have some relationship between any two data point (mean, std.dev.),
but, we do not know.
So, it makes... 阅读全帖 |
|
m******t
发帖数: 273 | 12 Thanks for all your help.
I have tried Moment Method, but the QQ-plot result is very bad.
How to know that truncated gamma pdf is the form of ?
g(x;shape,scale)/[G(b;shape,scale)-G(a;shape,scale)] on [a,b].
Are there some papers about that ?
'mean of log(data)' is unknown. We only know mean of data.
From, http://en.wikipedia.org/wiki/Gamma_distribution
If ln(x_i) is known, I can get estimated shape parameter. But, it is unknown
.
Any help would be appreciated.
First let's start with origin... 阅读全帖 |
|
p********1
发帖数: 2785 | 13 这是Amazon上Lin的评论。存在这里做个纪念：
As a Chinese, I lived through that period of time in China. I have similar
family and educational background as hers and suffered during Culture
Revolution as a child. I think her experiences in China mostly, if not all,
are fabricated, imagined, overly exaggerated or deliberately miss leading.
If one just read the media reports about her book, he/she may think that
media might just pick the sensational parts of the book and exaggerated a
little bit to help her to sell ... 阅读全帖 |
|
Z**********g
发帖数: 14173 | 14 【 以下文字转载自 Joke 讨论区 】
发信人: xiaxianyue (下弦月), 信区: Joke
标 题: 本钱老来点评基因编辑人类实验
发信站: BBS 未名空间站 (Fri Nov 30 14:48:36 2018, 美东)
刚花了半小时码了个长文，丢了，生无可恋……先占个坑。
你们，包括什么杀生丸都没说到重点。
先说一下贺的逻辑吧。多方证据显示携带CCR5delta32突变的人具有抗艾滋能力。而最
近大热的CRISPR/Cas9 genome editing技术使科学家现在有了“相对”定向修改DNA序
列的能力。所以利用CRISPR制造含有CCR5突变的人，会使该人获得抗hiv的能力。
这个逻辑门外汉看着会觉得相当很合理。很多在生物学界分一杯羹的物理/工程学家也
确实是按这个逻辑搞钱搞文章。可惜，贺还有贺的老板都缺乏真正的生物学背景。他们
和生物学家合作的时候没问题，但当他们自己开始搞生物，就会搞出大篓子。如果他们
在小鼠或者猴子里做这个实验，也就发一个二三流paper。但是他们野心太大，居然先
斩后奏做了人体实验。
接下来分几个点讲这个实验为什么破绽百出狗屁不通。
首... 阅读全帖 |
|
z*******4
发帖数: 285 | 15 算了，你脑子大概也被活摘过
懒得跟你解释，贴个清单吧：
累计研究数量 注册号 注册日期 研究者单位 研究者单位（英文） 注
册题目 注册题目（英文) 预计纳入参试者日期
1 ChiCTR2000029308 1/23/2020 武汉市金银潭医院（武汉市传染病医院）
Wuhan Jinyintan Hospital (Wuhan Infectious Diseases Hospital) 一项评价
洛匹那韦/利托那韦和干扰素-α2b联合治疗武汉新型冠状病毒肺炎(COVID-19)住院患者
的疗效和安全性随机、开放、空白对照的研究 A randomized, open-label, blank-
controlled trial for the efficacy and safety of lopinavir-ritonavir and
interferon-alpha 2b in hospitalization patients with novel coronavirus
pneumonia (COVID-1... 阅读全帖 |
|
t**********w
发帖数: 478 | 16 Then use the probability density function to calculate the conditional mean
and variance, provided you know where it is truncated at.
You should be able to obtain the truncated point through plotting, right? |
|
m******t
发帖数: 273 | 17 We know the truncated point.
But, how to use the probability density function to calculate the
conditional mean and std. dev. ?
We do not know the pdf of truncated gamma distribution.
Any help would be apprecitaed.
Thanks !
mean |
|
l*l
发帖数: 2043 | 18 多谢！
在我的邮箱里已经打开看过的邮件也能be retrieved？
还有办法把这个邮件恢复吗？
现在我能search到这个邮件，把光标移到这个邮件那一行上，pop up一个小窗显示这个邮
件的第一句话，但click这个邮件的话，就显示一个空白页。
而且，同一个标题的邮件被truncated，今天早上看这个truncated 里面还显示有26个
邮件，但现在只显示13个了，有什么办法能恢复过来吗？
一直以为打开看过的邮件，只要自己不删除，就会一直存在邮箱里，看来不是这样啊 |
|
i*u
发帖数: 299 | 19 这叫作truncation, which is a failure wave 5 that was not able to reach above
wave 3. "a truncation often occurs following a particularly strong third
wave"只怪我之前没认真看书。
详细请看一楼补充 |
|
a****t
发帖数: 7049 | 20 这段是文章里的关键
“In contrast, AlphaGo’s use of value functions is based on truncated Monte
-Carlo search algorithms
8, 9, which terminate rollouts before the end of the game and use a value
function in place
of the terminal reward. AlphaGo’s position evaluation mixes full rollouts
with truncated rollouts,
resembling in some respects the well-known temporal-difference learning
algorithm TD(). AlphaGo
also differs from prior work by using slower but more powerful
representations of the
policy and value... 阅读全帖 |
|
d*****n
发帖数: 908 | 21 HANDGUN AMMUNITION:
SELF DEFENSE
Ammunition manufactured in the United States is among the finest in the
world. For intended defensive uses, the gun owner will not go wrong in
selecting ammunition produced by the most widely recognized manufacturers.
These include CCI/Speer, Cor-Bon, Federal, Remington, and Winchester.
Allow no margin for error in protecting one's life. Avoid potentially
unreliable ammunition that is hand loaded, re-loaded, or of dubious quality
foreign manufacture when ch... 阅读全帖 |
|
N*****7
发帖数: 1899 | 22 开始积分差 0.98， implies 24.5 局分差
如果用truncate to 12 局 算0.48 分。 实际局差10局 （12-2）。
Adjustment = 0.48 - 0.04*10 = 0.08 / 2 = 0.04
blacklodoss > 4.23 - 0.04 = 4.19
TAMUGcy > 3.25 + 0.04 = 3.29
比较合理。
如果Adjustment 再除二， Adjustment = 0.08 / 2 / 2 = 0.02
blacklodoss > 4.23 - 0.04 = 4.21
TAMUGcy > 3.25 + 0.04 = 3.29
也合理。
（blacklodoss TAMUGcy） =〉 （3.94 3.54) 不合理 ：）
我做truncation的原因是如果 （6：0， 6：0） 双方比分不变， 那（6:1, 6:1) 应
改变 两局的比分 （0.08） 的一部分， 如0.04/0.02， 而不是 0.29.
not |
|
b*********s
发帖数: 6757 | 23 关于dynamic rating 算法，我们就用(前rating x 2 + 新rating)/3 的算法吧，
example below. 如果rating >=0.5， 就采用NJ08807的truncated 算法
A (4.25) vs B(4.13)
A wins 4-6, 7-5, 1-0(3)
A rating = (4.25x2+4.21)/3 = 4.24
B rating = (4.13x2+4.17)/3 = 4.14
I'm not 100% sure how the truncate works though. Can you explain again? I
assume if 4.02 vs 3.25, the way to calculate will bring 4.02 to 4.0 and 3.25
to 3.5, what then? |
|
d**********o
发帖数: 1321 | 24 我与Emacs的不解情缘（9）
差不多去年暑假后回学期也学会了自己写macro，贴个前段时间做题时写过的写lc的模
板吧：M-x lc ENT ：
(fset 'lc
[?# ?i ?n ?c ?l ?u ?d ?e ? ?< ?i ?o ?s ?t ?r ?e ?a ?m ?> return ?# ?i ?n
?c ?l ?u ?d ?e ? ?< ?v ?e ?c ?t ?o ?r ?> return ?# ?i ?n ?c ?l ?u ?d ?e ?
?< ?a ?l ?g ?o ?r ?i ?t ?h ?m ?> return ?# ?i ?n ?c ?l ?u ?d ?e ? ?< ?c ?s
?t ?r ?i ?n ?g ?> return ?# ?i ?n ?c ?l ?u ?d ?e ? ?< ?c ?m ?a ?t ?h ?>
return ?# ?i ?n ?c ?l ?u ?d ?e ? ?< ?s ?t ?a ?c ?k ?> return ?# ?i ?n ?c ?l
?u ?d ?e ? ?< ?q ?u ?e ?u ?e ?> retur... 阅读全帖 |
|
d**********o
发帖数: 1321 | 25 我与Emacs的不解情缘（9）
差不多去年暑假后回学期也学会了自己写macro，贴个前段时间做题时写过的写lc的模
板吧：M-x lc ENT ：
(fset 'lc
[?# ?i ?n ?c ?l ?u ?d ?e ? ?< ?i ?o ?s ?t ?r ?e ?a ?m ?> return ?# ?i ?n
?c ?l ?u ?d ?e ? ?< ?v ?e ?c ?t ?o ?r ?> return ?# ?i ?n ?c ?l ?u ?d ?e ?
?< ?a ?l ?g ?o ?r ?i ?t ?h ?m ?> return ?# ?i ?n ?c ?l ?u ?d ?e ? ?< ?c ?s
?t ?r ?i ?n ?g ?> return ?# ?i ?n ?c ?l ?u ?d ?e ? ?< ?c ?m ?a ?t ?h ?>
return ?# ?i ?n ?c ?l ?u ?d ?e ? ?< ?s ?t ?a ?c ?k ?> return ?# ?i ?n ?c ?l
?u ?d ?e ? ?< ?q ?u ?e ?u ?e ?> retur... 阅读全帖 |
|
r*t
发帖数: 34 | 26 An urgent problem, thanks a lot if anybody can help!!!
I have several parallel processes like this:
my_program parameter1 &
my_program parameter2 &
...
my_program parametern &
In most of time, it runs as expected, but sometime it do give me an error li
ke this:
"Truncating table TABLE_A, ORA-00054: resource busy and acquire with NOWAIT
specified"
I am very positive that I have already removed all the truncation codes from
my program, but I still have this kind of error. Could anybody give me a h |
|
s**********o
发帖数: 14359 | 27 靠，还dynamic sql statement，骇客的最爱啊，TRUNCATE TRUNCATE，DELETE DELETE
，DROP DROP你的TABLE就都没啦。 |
|
m********d
发帖数: 82 | 28 新客户的数据需要import到sql server 2000 database.其中一个column是notes field
,很长。在import过程中被告知text data being truncated。
请问如何才能不被truncate?谢谢。 |
|
|
r********r
发帖数: 208 | 30 在下面的程序中，对short类型s,无符号右移并赋值（见最后引用，这个操作中间经历
int, right shift, truncation 3个过程）。难道结果不应该还是short类型吗？可是
结果-1是int,32位.没想明白，很不爽。谁能解惑，指点迷津？
//: operators/URShift.java
// Test of unsigned right shift.
//import static net.mindview.util.Print.*;
public class URShift {
public static void main(String[] args) {
short s = -1;
System.out.println(Integer.toBinaryString(s));
System.out.println(Integer.toBinaryString(s>>>10) + ": s>>>10");
s >>>= 10;
System.out.println(Integer.toBinaryString(s... 阅读全帖 |
|
p****u
发帖数: 2422 | 31 from Advanced Bash-Scripting Guide:
http://www.tldp.org/LDP/abs/html/io-redirection.html
Chapter 20. I/O Redirection
Table of Contents
20.1. Using exec
20.2. Redirecting Code Blocks
20.3. Applications
There are always three default files [1] open, stdin (the keyboard), stdout
(the screen), and stderr (error messages output to the screen). These, and a
ny other open files, can be redirected. Redirection simply means capturing o
utput from a file, command, program, script, or even code block withi... 阅读全帖 |
|
K****a
发帖数: 161 | 32 我在目的基因CDS 3'端加了一个Flag-tag，然后转化Arabidopsis野生型，用的是35S
promoter。转化植株的第一代RNA水平高的株系挑选出来传代，第二代出现表型分离，
而且符合3：1的比率。用Northern检测第二代植株的RNA水平，发现出现特殊表型的植
株中RNA水平很高，但是用western检测不到蛋白表达。所以我设计了三段探针，分别用
目的基因CDS的前，中，后三部分，Northern结果发现前段和中段探针能检测到高表达
，但是最后一段却没有信号。
现在我想的是高表达的RNA不是全长，所以用Anti-Flag抗体检测不到蛋白表达。但是我
不知道为什么会出现这种情况。构建的用的是CDS，不含任何intron，按理说不会出现
alternative splicing。我现在想的是在5'端再加上一个HA-tag，转化得到过表达植株
，看看会不会出现相同表型，如果有的话，RNA是不是truncated，如果是的话，用Anti
-HA抗体检测看看有没有truncated protein存在。
遇到过这种现象的同学能不能指导一下，我想破脑袋也没想通。多谢！ |
|
d******u
发帖数: 178 | 33 即使只是truncate部分exon，KO一般会导致mRNA表达不稳定，如果有truncated
protein表达的话，KO是不成功的。
上面情况最可能的解释是：那个probe also detects other Bcl6 family members。查
一查那个probe的序列，然后看看Bcl6 family的同源性。 |
|
s******y
发帖数: 28562 | 34 你们以前做的实验，如果是用片段作的话，和用全长蛋白做起来
结果是有可能有差别的，
可能性之一就是你们那个全长蛋白需要激活变构后才能暴露出那个结合的肽段来和底物
结合。要证实这个的话，可以做几段truncation, 看看是否有truncate 能够
和你们的底物结合。
另外一个可怕的可能性，就是你们用肽段做出来的是不符合生理环境下的伪结果。 |
|
l******g
发帖数: 1623 | 35 怎么样证明一个protein可以self cleavage, 而不是其他的protease协助。这蛋白在体
内也是会cleaved，没人得到过full length的，文献上说是其他protease切的。我做的
recombinant, 无论真核还是大肠杆菌表达出来的，都不稳定，纯化出来的都是full
length 和 truncated 在一起。4度放放，过夜都会变成truncated. 我怀疑这蛋白自己
切了自己，不知道怎么证明。 |
|
s******y
发帖数: 28562 | 36 提纯不需要太长时间，应该没有问题，他也说了，提出来的是一个全长和
truncate 的 mixture ，放过夜之后才会变成truncate.
所以说明在一开始至少有一定比例是全长的，肯定是可以提出来的。 |
|
l**********1
发帖数: 5204 | 37 LZ为了过份表达 选的promoter inserted xxxxx bases upstream of the Start codon may affect the Kozak
sequence or rbs.
then a nonsense mutation is a mutation that causes a premature stop,
resulting in a truncated or nonfunctional protein
NB: if it is my misunderstood please let me know it.
回复]
>发信人: vonda (Vonda), 信区: Biology
标 题: Re: 用qPCR检测mRNA，高1000倍，却看不到蛋白
发信站: BBS 未名空间站 (Tue Jan 31 19:01:56 2012, 美东)
天……我overexpress的是一个extensively studied的蛋白。。。没有文献报导过它不
稳定。那是阅读框错了？但是overexpress后，细胞的一些signaling pathway... 阅读全帖 |
|
l*********1
发帖数: 351 | 38 比方说这个膜蛋白有truncated version (就是胞外区结构),该truncated version存在
于胞内，并有独立的功能。不知道这样解释是不是更加明确点? |
|
l***i
发帖数: 36 | 39 truncated 蛋白和全长蛋白序列一样，过柱子不就全部吸附了，特异识别truncated的
怎么会flow through？ |
|
q**i
发帖数: 174 | 40
maybe I'm naive, but once you exercize the option, some branches of the
tree will be truncated. the reason you can get a beautiful solution
on european options is the symmetrics of the tree. I don't know, and
I doubt if that beauty can be preserved if the tree is truncated.
maybe I should dig out my copy of Hull's book (which I remember
as most dealing with continuous time).
I still think the difficulty is mutual excusivity of cash flow
from the bond and exercising of the option. this problem i |
|
J**Y
发帖数: 34 | 41 My experience is that the values of latent variable from truncated normal
are easily to explode. You may want to add some truncations into your code.
Additionally, since you normalize the 1st diagnol element of covariance matrix
as 1, you can not still assume this matrix is wishart distributed. You can
check a recent paper (2000) in J. of Econometrics to see how to estimate
this kind of identified MNP model by Bayesian.
An easy way is to work on unidentified model, in which you specify priors
on |
|
e********I
发帖数: 693 | 42 ☆─────────────────────────────────────☆
dixit (dixit) 于 (Tue Feb 26 01:10:06 2008) 提到:
报告一：
题目：Estimation of the Truncated Density Function at Its Unknown Truncation
Point with Application to Estimation of the Entry Cost in First-Price
Auctions
报告人：Pai (Steven) XU (University of British Columbia)
时间：2月19日周二2:00-3:30pm
地点：光华楼201室
报告二：
题目：Information, Advertising, and Consumer Choice in an Experience Good
Market: an Application to the Ready-to-Eat Cereal Market
报告人：Yan CHEN (University of Mar |
|
a*********n
发帖数: 1331 | 43 第一次用heckman two step to correct selection bias. 我用的stata12。可是总是
出错 。帮我看看哪里不对？
error message "Dependent variable never censored because of selection: model
would simplify to OLS regression"
我的情况是有一半的cases missing dependent variable information(outcome),所以
是truncated的情况。 这种情况那个dependent variable应该怎么code？ 我的是0＝no
,1=yes, 9=truncated missing outcome。 这样code对吗？ 要不要把9这个category直
接改成
。（missing）？
另外我的程序如下，到底哪里错了？
heckman outcome iv1 iv2 iv3, select(var1 var2 var3) twostep |
|
a*********3
发帖数: 660 | 44 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 |
|
|
f***a
发帖数: 329 | 46 simulate x from N(mu,sigma^2)
let A=x if x in [a,b]
then A follows truncated N(mu,sigma^2) in [a,b]
但是你对A做inference的时候就不能用N(mu,sigma^2)的pdf了，要用truncated normal
distribution的pdf
了。 |
|
t*****s
发帖数: 49 | 47 路过的牛人请分析一下。我下周考base。多谢先。
Q30 我的疑问---关于auto conversion of character-to-numeric variable:
当character variable和一个numeric value比较时，auto conversion will happen,
为什么这里不行？
when a character variable compared to a numeric value, the character
variable will be auto-converted to numberic variable --- from SAS base Prep
Guide P402
以下程序我在sas上试过了，的确是d，但不明白为什么这里不自动转换。
Q30.The descriptor and data portions of the Work.Salaries data set are shown
below.
Variable Type Len Posname Char 8 0
salary status ... 阅读全帖 |
|
f*****k
发帖数: 110 | 48 为嘛只得到空白而不是想要的结果呢？如何合理粗暴？
data trial ;
length x y $6;
input x ;
y=cats(x, '000000');
datalines;
345
4567
777777
23567
;
run;
WARNING: In a call to the CATS function, the buffer allocated
for the result was not long enough to contain the
concatenation of all the arguments. The correct result
would contain 11 characters, but the actual result may
either be truncated to 6 character(s) or be completely
blank, depending on the calling environment. The
... 阅读全帖 |
|
g*******i
发帖数: 258 | 49 are you saying probit with Bayesian estimation proposed by Chib?
The biggest problem with probit is it needs to deal with truncated normal,
which bothers researchers for decades. Even now truncated normal takes lots
of time. In real applications, people rarely use probit, even though it is
free from the independence of irrelevant alternatives restriction. Most
people, including some well developed business packages, use logistic and
ignore this IIA assumption in trade of efficiency.
convenient |
|
D*********Y
发帖数: 3382 | 50 这个要讨论一下。TOBIT是不是用在truncated 和censored data？如果数据本身不是
censored或者truncated，用tobit好像也不对。
比如LZ这个如果数据都在，而且不是censored，就是全部observable，就是0-4，就像
ownership 只能是0-100%一样。
这该用什么呢？
PS，我的毕业论文里面有这种情况，用tobit，结果committee不高兴。suggest OLS，
但是也不对。suggest ordered logit，（把数据分成一段段，create discrete value
--但是我觉得这样也不是censor了一些信息吗？我觉得也不对）。其实呢，不管哪种办
法，结果都差不多。
要么就OLS， above 4就当4，below 0就当0，可行吗？ |
|
