f****n
发帖数: 208 | 1 Based on my experience, these are the popular ones:
1) Final, finally and finanize key words understanding
2) Synchronized keyword and wait, notify (notifyAll) situation.
3) Serialization understanding, Static varible serialization?
4) Method overiding and overloading and shadowing
5) Java 5 features, Autoboxing, Generics...
6) Exception handling, Excepetion classes structure, checked and non checked
exception, throwable and error class
7) Collections, Differenece between arraylist, vector and l |
|
f****n
发帖数: 208 | 2 Based on my experience, these are the popular ones:
1) Final, finally and finanize key words understanding
2) Synchronized keyword and wait, notify (notifyAll) situation.
3) Serialization understanding, Static varible serialization?
4) Method overiding and overloading and shadowing
5) Java 5 features, Autoboxing, Generics...
6) Exception handling, Excepetion classes structure, checked and non checked
exception, throwable and error class
7) Collections, Differenece between arraylist, vector and l |
|
f****n
发帖数: 208 | 3 Based on my experience, these are the popular ones:
1) Final, finally and finanize key words understanding
2) Synchronized keyword and wait, notify (notifyAll) situation.
3) Serialization understanding, Static varible serialization?
4) Method overiding and overloading and shadowing
5) Java 5 features, Autoboxing, Generics...
6) Exception handling, Excepetion classes structure, checked and non checked
exception, throwable and error class
7) Collections, Differenece between arraylist, vector and l |
|
s******e
发帖数: 493 | 4 Oh man. I am just wasting my time...
PLEASE read my post CAREFULLY. Did I ever say that inner class has to keep a
local reference to the enclosing class variables? Here is what I said:
let me give you a better example to help you understand
public class A
{
private int i;
Class B
{
public int getI()
{
return i;
}
}
}
in this case, since once compiled, class A and B will be independent (not
mean that they are not coupled) classes, if we allow B to access A's private
var... 阅读全帖 |
|
x**m
发帖数: 941 | 5 最直接可以用case。
要fancy的话，我试了试varible substitution, 不过好像都不work。需要高人指点。
#!/bin/bash
VAR1=11
VAR2=22
VAR3=33
var=$1
v=VAR$var
echo ${$v}
echo ${VAR$var}
echo ${VAR{var}}
echo ${VAR{`echo $var`}} |
|
f********a
发帖数: 1109 | 6 匈牙利命名法? 骆驼包装？
还是自己有更好的方法？
我一般有几点：
member function用 m_
static varible用 s_
函数名手字母大写
还有什么补充？ |
|
c********x
发帖数: 84 | 7 When the OS loads a program into memory, it maintains a table of variables
you would use, the your program exits, the OS recycles the
table of variables, but the OS can't tell which varible is a pointer to free
the memory on heap. |
|
h**o
发帖数: 347 | 8 but you cant use a pointer to a member function.
static member function does not necessarily mean there must be static
varibles. it really depends.
you shouldnt write the code like this anyway. that may creat a loop of
function calls |
|
b***y
发帖数: 2799 | 9 ☆─────────────────────────────────────☆
catbert (mimi) 于 (Tue Sep 27 16:15:22 2005) 提到:
Does it make sense to always use namespace, instead of the conventional way of
declaring varibles? Thanks.
☆─────────────────────────────────────☆
tuling (耕耘) 于 (Wed Sep 28 02:54:25 2005) 提到:
use anonymous name space would work in many cases.
of
以下是附件内容: |
|
e********r
发帖数: 2352 | 10 (1)server side 的string type内存是怎么分配的：
在.x文件里定义了:
typedef string nametype<100>;
struct candidate
{
nametype name;
int number;
}
在server文件里定义一个array:
candidate array[10];
arry[0].name 怎么好像和array.name[1] 共用内存，改了一个另一也会变, 请问哪位
老大可以指教一下.
(2)还是上面这个struct，可以从client side 传一个candidate type varible 到
server, 但是从server 传一个candidate到client就会crush, 这两个问题是不是都是
因为server side内存分配的问题. |
|
w**n
发帖数: 88 | 11 Probably that is the case: Gnu complier does not come with solaris, the
lib location is totaly decided by the admin who installed it.by default,
it should be in /usr/local/lib.
So, find out the file, add the cresponding path to your LD_LIBRARY_PATH
varible. |
|
j*****o
发帖数: 320 | 12 Control Panel -> System -> Advanced -> Environment Varibles |
|
h*******o
发帖数: 4884 | 13 另外， 在补充一点，我个人的理解是p value就算=1也不能说两组完全一样
比如做bioequivalence study时，要求是90% CI在reference list drug的 80% -125%
之间，如果是上面的例子， 估计也会fail equivalence study。
更简单的说法是equivalence study，要设置equivalence margin，如果你的CI 在
margin 里面才能叫做equivalence，你的例子的第二组varibility很大，STDEV很大的
话，有可能导致CI过equivalence margin,当然这只是目测，具体是不是还是要算出来
才知道。 |
|
a*******o
发帖数: 280 | 14 You argued a lot on individual variability. I assume this varibility
explains why you feel so passion about Stern PT, while many other people (
seems to be a quite notable number) felt that Stern ripped them off.
a
most
- |
|
a***u
发帖数: 72 | 15 gcc -g foo.c
gdb a.out
in gdb
run
to set break points,
l (to list)
break
run (or c to continue, s to step, n to next, ...)
print a (to print the varible a). |
|
w*********r
发帖数: 488 | 16 you can transform the variable x to its associated probaliliy given that you
know this varible has what kind of distribution. for example:
phi(x)=z, z belongs to [0,1], the unbounded integral is transformed into the
bounded integral ,but you also need to changed the pdf , new pdf is equal to
the "old" pdf times the Jacobian of the transformation. |
|
p***c
发帖数: 2403 | 17 只有一个r.v.，收敛个屁啊
如果是一列
1. for all K>0, \lim_n P(X_n<-K)=1
2. P({w|\lim_n X_n(w)=-\infty})=1 |
|
|
n***a
发帖数: 1373 | 19 could be.
There could be a small varibility, like a week earlier or later. |
|
k***g
发帖数: 7244 | 20 呵呵，那就不知道了，我见过的ordinal的dependent varible一般都是按照“strongly
agree, agree, netural, disagree, strongly disagree"这样排列的。。。你做的那个
东东以前遇到的时候，用的都是multinomial probit， 譬如以前做过一个关于alliance
type的回归分析，DV是 defence pact, netraulity or nongaggression pact和entente
，不知道能不能和你那个构成类比。。。呵呵，没有做过以人为对象的回归分析，都是以
国家或是economy，polity为对象。。。
按
Logit
都
，
里
了
do
and
protest
意
游 |
|
b***k
发帖数: 2673 | 21 我可以做出这个题，答案是t^3/6
但过程非常繁琐，一步一步推导，
要两次分部积分，ito isometry，fubini theorem等
想问一下有没有更加简单直观的方法直接给出答案的？
其实这个题很有意思，这里X和Y都具有如下性质：
E(X)=E(Y)=0
D(X)=D(Y)=t^3/3
且都是normal distribution random varible，对不对？
Old.版内查。 |
|
x******a
发帖数: 6336 | 22 如果知道D(X)和D(Y),可以考虑
X+Y=tB_t,
t^3=E((X+Y)^2)=2E(XY)+2t^3/3,
E(XY)=t^3/6.
不过D(X)怎么才能更简单直观?
我可以做出这个题，答案是t^3/6
但过程非常繁琐，一步一步推导，
要两次分部积分，ito isometry，fubini theorem等
想问一下有没有更加简单直观的方法直接给出答案的？
其实这个题很有意思，这里X和Y都具有如下性质：
E(X)=E(Y)=0
D(X)=D(Y)=t^3/3
且都是normal distribution random varible，对不对？
Old.版内查。 |
|
D**u
发帖数: 204 | 23 Randomly (also uniformly) choose 3 points A,B,C on a 2-dimensional sphere.
Let x be the spherical area of the spherical triangle ABC;
and y be the volume of the (Euclidean) 四面体 formed by A,B,C and O
(the center of the sphere).
If we treat x and y as 2 random varibles,
then what is the correlation between x and y? |
|
p********a
发帖数: 5352 | 24 ☆─────────────────────────────────────☆
joypp (猪头) 于 (Thu Feb 15 16:08:18 2007) 提到:
I have a problem with data manipulation, it might be easy for you.
The database contains hundreds of varible, I want to recode the data
according to the same rule; 0=1 1; 1= 1 2; 2= 2 2;also delete all the Id
with missing data.
the old database lokks like,
ID ns-rs1102 ws-ns11232 ns6433 ns2209 ns6473
1 0 1 2 1 2
2 1 |
|
r****n
发帖数: 144 | 25 可是我不知道我的第一个variable在data中是第几位
我的data有几百个variable，要的是其中几十个variable
这些varible的名字特点是这样
97_1 ......到97_12
98_1.......到98_12
.
.
.
.
07_1.......到07_12
我用最原始也是最冗长的方法可以读，但是总觉得有其他更有效的方法 |
|
o****o
发帖数: 8077 | 26 for empirical testing
you can try CMH under 3-way contingency table. But need to combine all the
conditional varible subset Z's and generate a single categorical variable
containing all levels of combinations |
|
x*******u
发帖数: 500 | 27 两组数据, 一个sample size 20左右, 一个900左右. 想比较这两组数据的几个var
iable的mean或者median, 请问该用什么方法. 谢谢
这几个varible在小的那组数据里
有的left skew, 有的right skew, 都不normal. |
|
j*****e
发帖数: 182 | 28 Repeatly measure a subject 10 times decreases measurement error. Varibility
from subject to subject determines if you are going to see significance, or
not. Basically, your outcome is the average of the 10 measurements from each
subject. You are comparing the mean of two samples, each with size two.
Nonparametric test will not save you. It will give you a p-value that is
larger than 2-sample t-test.
There is no majic in statistics. You have to collect information from more
subjects. |
|
h******e
发帖数: 1791 | 29 是分组的问题，检查你的by statement后的variables是不是对应多个var statement
后varible的值。或者事实let option 在transpose statement 里。 |
|
d******1
发帖数: 92 | 30 two sample permutation t-test: in the data we have two group( T and C), so
the varible "group" is equal to either T or C, and the response variable is
continuous which is "total score", dataset name is "q2"
Use Monte carlo method to perform one side permutation t-test, to test two
group mean difference. (significant level 0.025)
how to write code, please help, hw will due soon, so worry, if you need data
, i can send |
|
h******e
发帖数: 1791 | 31 比如总数多少，character多少，numeric多少，存到macro varible里。 |
|
s********9
发帖数: 74 | 32 I tried to convert variables from Character values to numeric values in SAS
by use x=x+0, while this method worked for some variables, but failed for
some variables.
My data is originally from Access, I convert them into xls file and imported
into SAS. |
|
s**********e
发帖数: 63 | 33 Use "Input" statement:
For example:
input("varname", length);
run; |
|
h******e
发帖数: 1791 | 34 用这种方式sas log不会“干净”的，应该用input function。
SAS
imported |
|
a***r
发帖数: 420 | 35 这个问题以及很多跟factor相关的问题，都真的搞得我很痛苦。。。
我以为我明白factor，numeric，character的区别，在字面上是很容易理解（？），可
是一自己写code，就会被无数莫名的问题折磨，（尤其跟factor有关的。。。）然后跑
去找教程，看了教程以上循环重复。。。
比如，我读入了一个variable用tab隔开，但是varible中间有空格的datafile，于是用
的：
data <-read.table("data.txt",sep="\t",strip.white=TRUE)
数据第一行如下：
V1 V2 V3 V4 V5 V6 V7 V8 V9 V10 V11 V12 V13 V14
1 139930032001 139930032001 0 0 2 2 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2
从第七列开始，都是1 1；2 2；这样的格式，中间有一个空格
然后R认为他是factor
于是我写
data[,(6+1):(6+n)] <-as.character(data[ |
|
l***y
发帖数: 207 | 36 我在整理数据的时候碰到一个问题，想了很多办法都没有弄出来，请问各位谁能给我点
建议，非常感谢。
我的原始数据是这个样子的
name good P1 P2 P3 P4 P5 P6 P7 P8 P9 P10
good P1 P2 P3 P4 P5 P6 P7 P8 P9 P10 这个11个全部都是binary variables，如果满
足就是1，不满足就是0。我最后想把数据整理成下面的样子：
Good P Yes Count
Good还是一样，是binary variable
P代表是P1 P2 P3 P4 P5 P6 P7 P8 P9 P10 中的一个
Yes也是binary varible,他对应着前面的P。比如说一个产品，是好产品Good=1,然后看
这个产品是否满足P1到P10,如果满足相对应的P，那么Yes就是1，否则就是0。
Count就是数有多少个这样的observation。最后数据大概应该是
Good P Yes Count
1 P1 1 200
1 P1 0 600
0 P1 1 200
0 P1 0 100 |
|
s*******e
发帖数: 1385 | 37 没有太看懂你的race=B是什么意思，是说race这个varible有四个level吗？ |
|
n******0
发帖数: 298 | 38 The outcome is Cancer vs. Normal
The explanatory varibles are four protomics peaks
The following is the results:
Analysis of Maximum Likelihood Estimates
Standard Wald
Parameter DF Estimate Error Chi-Square Pr >ChiSq
Intercept 1 -1.7465 1.4500 1.4509 0.2284
c14 1 -2.4761 0.8573 8.3430 0.0039
c25 1 7.7777 2.4119 10.3987 0.0013
c46 |
|
w****e
发帖数: 1013 | 39 我需要分析一堆数据，但是之前只上过简单的统计课，基础比较差，现在搞不定了，上
这里来请教一下各位专业人士。谢过了先！
这堆数据包括一个response variable，24个dependent variables，其中20个是
continuous的，另外4个是categorical的。一共400个samples。最终目的就是想看看哪
些dependent variable对于response varible的影响比较大，包括interaction effect
。我的问题是：
（1）是用anova还是用regression analysis比较合适？
（2）我目前正在研究用anova怎么弄。根据网上看的资料我的理解是因为这个既有
continuous variable，又有categorical variable,所以需要用ancova (analysis of
covariance。不知这个理解正确不正确。
（3）看了matlab里面做ancova的function，感觉找不着边。同时在matlab里面anovan
可以做Nway的anova分析，而且可以标明哪些变量是conti |
|
s***r
发帖数: 1121 | 40 Varible
1234
123
567890
....
I want to remove the last digit; that is, 1234 -> 123; 123-> 12; 567890->
56789.
Anyone can help me? Thanks a lot.
One baozi will be given for your kind help. |
|
p******r
发帖数: 1279 | 41 做regression的时候，如果indep var里面有categorical类型的var，比如
salary=experience+edu+error 里edu是categorical变量，值为1 2 3 ，1代表高中
，2代表大学，3代表graduate school。
那我把它当成数字1 2 3然后直接做regression，得出一个beta值
和我把它变成几个dummy var来做one way anova得出几个fix effect的coefficient
这两种做法，在本质上有啥区别呢？ 感觉除了手法上有区别，其他比如predict或者衡
量edu对salary的effect来看，没啥大区别啊？
还有在SAS里coding的话，如果edu的变量类型一开始就定义为categorical的话，那用
proc glm是不是就不需要事先create dummy varible？
请赐教！！ |
|
p******r
发帖数: 1279 | 42 no, I mean when you try to run zero-inflated negative binomial model, the
SAS coding is like:
proc countreg data = depression method = qn;
model depscore = x1 x2 x3 / dist= zinegbin;
zeromodel depscore ~ x?;
run;
In addition to specify the "model", you have to specify the "zeromodel" as
well.
But which indep varible shall I shoose to put into "x?" ?
Shall I just try x1, x2 or x3 arbitragely one by one to see which one has
good fit?
the |
|
p****8
发帖数: 50 | 43 答案是A，为什么其他答案不对啊？我人认为因该选D。后面有我设计的test code。给
出相同结果。
Item 52 of 63 Mark item for review
To create a dataset with unique values of
a given varible using a data step and the
FIRST. and LAST. varaibales, it is assumed
that the input dataset is:
A.
sorted on that variable.
B.
indexed by that variable.
C.
naturally in order.
D.
any of the above A, B, or C
============================================
*natually in order;
data a0;
input x y z;
da... 阅读全帖 |
|
h**********6
发帖数: 66 | 44 假设A，B follow一个函数关系，对于每一个固定的B（已知），有5个A值与之对应，这
5个A假设follow normal distribution，然后我要通过A的varibility去估计C的var，C
和A follow以下关系： C=∑A*B。要用bootstrap估计C的confidence interval。
谢谢~~ |
|
s******o
发帖数: 283 | 45 Item 52
To create a dataset with unique values of a given varible using a data
step
and the FIRST. and LAST. varaibales, it is
assumed that the input dataset is:
A. sorted on that variable.
B. indexed by that variable.
C. naturally in order.
D. any of the above A, B, or C
答案为何不是D？因为这里只是要求unique value，所以在同一个组里的任意一个值都可以，所以在
这里对顺序并没有要求，所以并不要求sort or index or any order？？？？ |
|
y********0
发帖数: 638 | 46 都是关于index的..发现自己只要是关于index的题,都是全军覆没.
1 To create a dataset with unique values of
a given varible using a data step and the
FIRST. and LAST. varaibales, it is assumed
that the input dataset is:
A.
sorted on that variable.
B.
indexed by that variable.
C.
naturally in order.
D.
any of the above A, B, or C
这个答案是A,我咋觉得AB都行啊.谁知道能给解释一下吗.
2. The SAS data set WORK.TEST has an index
on the variable Id and the following SAS
program is submitted.
data ... 阅读全帖 |
|
t*****8
发帖数: 157 | 47 今天我的同事说logistic regression中的ROC curve可以用来比较变量。比如说，
dependent variable 是y, independent variable x1 ，ROC curve是0.8；dependent
variable 还是y, independent variable 换成 x2, ROC curve是0.6. 所以x1比x2是
更strong的predictor。我印象， ROC curve只能用来看model是不是fit well， 如果
比较varible， 应该用p value. 我对还是我同事对？ |
|
c**********2
发帖数: 62 | 48 SAS ADV 63题网上的答案有很多版本，貌似都有一些错误。下面是我仍然拿不准的一些
题目。欢迎讨论，指正。等考完若有时间再把整理的63题答案发出来积点人品。
Item 1 of 63 Mark item for review
When attempting to minimize memory usage, the most efficient way to do group
processing whenusing the MEANS procedure is to use:
A. the BY statement.
B. GROUPBY with the NOTSORTED specification.
C.the CLASS statement.
D.multiple WHERE statements.
答案选C，个人也认为C是对的。网上有人提到过用Sort再means,这样A更快。但是题目
问的是memeory，不是时间，所以觉得还是应该选C。
Item 11 of 63 Mark item for review
The following SAS code is subm... 阅读全帖 |
|
n******u
发帖数: 79 | 49 我有一个dataset里面有一些varibles含有missing value
我想用SAS 的proc MI 去impuate missing data。
我打算 用 statement “nimpute=5”来产生５ 个 imputed datasets。
可是之后怎么将这5 个 imputed datsets combine 成一个 最终的 dataset 呢？
是要算平均值吗？
没有用过proc MI ， 请大牛赐教。 |
|
