l*******y
发帖数: 490 | 1 Read any text book for MD.
Like "Computer simulation of liquids".
I guess you're talking about how to fit a potential.
If you know the physical meaning, use some analytical
potential for fitting. For example LJ potential.
If you have no idear about the analytical form, you
can try Sum(An/r^n) if the potential has the boundary
condition U->Inf as r->0 and U->0 as r->Inf.
If neither of above method is good, just use the
tabulated potential as it is. In this case maybe you
need to do interpolation |
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w****g
发帖数: 44 | 2 Thanks. In my case it would be a tabulated potential as it is.Do you know
any free code can do such work ? I remember somebody claimed that this will
be faster than the normal function calls. Please let me know if you know
somebody did such work and have such programs
thanks |
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l*******y
发帖数: 490 | 3 You can use GSL, to fit your data in a cubic spline form. The algorithm
is also in the book "the numerical recipes". I think many MD code support
tabulated potentials, like DL_POLY, GROMACS etc.
will |
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c****e
发帖数: 252 | 4 I need some sort of literature where the Kuhn segment length (or,
alternatively, the persistence length) is tabulated for polymers,
especially for polycarbonate, polyetherimide and PBT.
Thanks, |
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i***0
发帖数: 8469 | 5 Hello,
My name is Shalley and I'm a recruiter at Artech.
Artech has an urgent contract for one of our direct clients:
Job Title: Statistical Programmer - SAS
Location: Bridgewater, NJ
Duration: 3+ Months
Job Description:
Duties:
Provide statistical programming expertise (preferably in SAS) in the
production of analyses, tabulations, graphics, and listings from clinical
trial data. Key responsibilities and skills include, but are not limited to,
the following: Contribute to the preparation of |
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f*******d
发帖数: 339 | 6 I need to calculate at points r1, r2, ... r_max the function f(r)
given
by
f(r)= \int_0^\infty g(k) sinc(kr) dk, where sinc(x)=sin(x)/x, g(k)
is a tabulated function. Now I can certainly do the integral one by
one, but hoping to use FFT to improve efficience, I observed that this
can be rewritten as
f(r)=1/r \int_0^\infty g(k)/k dk, which is just the sine
transformation.
So, I used the program sinft given in numerical recipes to
do the calculation. However, it seems that the result is very
bad a |
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S***y
发帖数: 186 | 7 SUBROUTINE SB(LMAX,Z,JL)
INTEGER::LMAX
COMPLEX::JL(0:LMAX),Z
INTEGER::L
COMPLEX(KIND=8)::DJL(0:LMAX),NORM
DJL(LMAX)=(0.0D0,0.0D0)
DJL(LMAX-1)=(1.0D0,0.0D0)
DO L=LMAX-2,0,-1
DJL(L)=(L+L+3)*DJL(L+1)/Z-DJL(L+2)
END DO
NORM=DJL(0)
DJL(0)=SIN(Z)/Z
NORM=DJL(0)/NORM
DO L=1,LMAX
DJL(L)=DJL(L)*NORM
END DO
JL=DJL
END SUBROUTINE SB
This subroutine tabulates Spherical Bessel Function in JL(0 |
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h*******e
发帖数: 68 | 8 ☆─────────────────────────────────────☆
barry (大狗) 于 (Wed May 23 16:20:13 2007) 提到:
我以前没搞过SAS，最近刚接触。
想做一个通用程序，按着用户的要求生成descriptive表格。
给一个大的DATASET，用户指定表格的表头是什么，表行是什么，
基本上表头表行都分几级，信息基本上是mean, SD, p value
问题就是要自动生成EXCEL表格。
用SAS做好累啊，因为要自动填表，肯定要很细地操作DATASET
里的数值，SAS又没这功能，只能全转到MACRO变量了，用宏来处理，
还考虑用PROC SQL，太不顺手了。
大家有什么建议吗？
☆─────────────────────────────────────☆
espace (爱因斯坦) 于 (Wed May 23 16:53:31 2007) 提到:
这就具体问题具体分析了。
看你的情况，大致应该是先用
proc means
output out=......
然后用proc tabulate
☆───────── |
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h******n
发帖数: 232 | 9 如何能将一个dataset打成如下表格：
dataset：
grp year loss interest
EXA 2004 123 12
MGR 2005 234 13
MGT 2006 345 23
EXA 2004 456 23
MGR 2005 457 45
MGT 2006 478 15
... .... ... ..
想要得到的表格如下： |
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c*******7
发帖数: 2506 | 10 proc report works too.
proc reports data=have nowd;
column year grp,(loss interest);
define year/group;
define grp/cross;
define loss/analysis sum;
define interest/analysis sum;
run; |
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l****e
发帖数: 15 | 11 "year all" instead of "year=''" |
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x***n
发帖数: 103 | 12 另外这个好像proc freq 没问题，proc tabulate就有问题了 |
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q**j
发帖数: 10612 | 13 这个pivot table真的是 MS 给不懂编程的利器。如果数据不多，真的顶上了SAS的proc
means, proc summary, proc report and proc tabulate. 挺牛的。 |
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q**j
发帖数: 10612 | 14 你没有把问题说明白。真的没办法帮你。
最好文之前把问题简化一下。问题有个重点。
proc freq有时候不好用。复杂问题推荐proc report or proc tabulate. i would pre
fer proc report.
新手求助~~超级感谢!
要求每一个subset接受某treatment的expected数量.
For Standard Population, I got the form by proc freq. There are about 1000
categories.
____________ ________________
Categories Treatment Rate
____________ ________________
1 R1
. .
. .
i Ri |
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c*****m
发帖数: 4817 | 15 table, or ctab in catspec |
|
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l*****k
发帖数: 587 | 17 土死了， 呵呵
table(data[,1], data[,2])
多谢 |
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o****o
发帖数: 8077 | 18 哥们儿，发点包子鼓励一下嘛，我上班回帖也不容易的 |
|
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y****1
发帖数: 400 | 21 Can you be more specific?
If some statistics are zero they should be displayed zero~
Did you mean missing values? |
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y****1
发帖数: 400 | 22 人数的话统计量就是N喽？
我都是修改missing value的输出格式了，不然你把程序贴上来看看？ |
|
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d*****6
发帖数: 100 | 24 下周有个1小时的电话面试，求建议如何准备？这机会对我很重要，请各位给些建议！
！多谢了！！
还有 什么叫ETL processes？？
职位：clinical SAS programmer
单位：Heath care system
面试人： biastatistician
我教育背景：MS in biostatistics
job description: must have strong SAS programming skills with respect to
ETL processes (data step, PROC SQL), report writing (SAS/GRAPH,PROC
REPORT, PROC TABULATE, ODS).Familiarity with basic statistical procedures
is required. |
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S******y
发帖数: 1123 | 25 I am comparing kknn and logistic regression for binary outcome prediction -
For kknn, I can do -
kknn_<-kknn(out_come ~ age + gender , learn_, valid_)
fit<-fitted(kknn_)
table(valid_$out_come, fit)
to get validation results in cross-tabulation. |
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q****k
发帖数: 1023 | 26 Proc Report is said to be much useful than Proc Tabulate in pharm.
time
I |
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n******e
发帖数: 476 | 27 恩，我在工作里从来都没用过 proc tabulate |
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p********a
发帖数: 5352 | 28 问问SAS，MACRO/SQL/data step merge/join/first.var/retain/rotate/import
统计的基本不问，画图的基本不问,report/tabulate不问
再问问你知不知道claims structure,ICD9/CPT/revenue codes等知识
俺很久以前替公司招人出了个SAS TEST和CLAIMS KNOWLEDGE TEST, 不过现在找不到了
。对新人来说，确实是行为问题问得多些，但SAS还是一定要问的。 |
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l***a
发帖数: 12410 | 29 proc tabulate data=one missing out=one_xy;
class x y;
table 'x', x*(n pctn);
table 'y', y*(n pctn);
run;
work out x and y separately and union one_x and one_y
one |
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P*******0
发帖数: 226 | 30 一个local biotech,之前在系里贴summer intern 广告，就投了
刚才忽然打电话过来，吓了我一跳，
问我做过什么，为什么对他们感兴趣，
SAS procedure用得最多是什么，
有没用过proc sql, tabulate,
有没有在Unix system 用过SAS,(我都照实说没有)
然后让我明天过去公司面试。
大家给点建议吧，>_<
这么短时间能看什么呀。 |
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p*****0
发帖数: 3104 | 31 NOTE: The SAS System stopped processing this step because of errors.
NOTE: PROCEDURE TABULATE used (Total process time):
real time 0.07 seconds
cpu time 0.01 seconds
289 ODS RTF close;
ERROR: Errors printed on page 11.
有一个文件出现了这样的错误，不知道从哪里找问题。
请指教。多谢。 |
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s******y
发帖数: 352 | 32 Code works only on SAS9.2.
data class;
set sashelp.class;
array temp $10. name sex cheight cweight cage;
cheight=cats(height);
cweight=cats(height);
cage=cats(age);
do over temp;
if ranuni(123456)<0.3 then call missing(temp);
end;
keep name sex c:;
run;
proc print;
run;
proc format;
value $miss " "="missing"
other="nomissing";
run;
proc tabulate data=class missing out=out;
class _character_;
table _all_,N;
format _character_ $miss.;
run;
data want(keep=var N rename=(N=miss));
set out;
array all |
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s********8
发帖数: 45 | 33 大家好，知道这里都是学统计的，我这个夏天刚选修 一门统计课。 有个课题不会作，
我把问题 copy 到这里。希望大家帮帮我。先谢了。
Use the data set supplied (hypertension, diabetes, cholesterol in subjects,
including medication, weight, age, etc) in docsharing and using Excel,
provide the following for Frequency the variable(s) of your choice:
1 distribution of a variable and bar graph of the same variable
2 Descriptives of a continuous variable: mean, median, mode, skewness,
kurtosis, standard deviation
3 Cross tabulation of two variables
4 Comp |
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g**r
发帖数: 425 | 34 酷！
稍微改进了一下，最后用的这个：
t(apply(a,1,function(t)tabulate(t,ncol(b)) |
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a*****3
发帖数: 601 | 35 i'd use proc freq or Tabulate, hahaha. I know i'm lazy a.
btw 等我弄完手里的活 晚上来写code 拜托大家不要和我抢包子啊。
bow// |
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j******n
发帖数: 2206 | 39 大家说说这两个各自的优缺点，以及你们觉得哪个更方便？ |
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c*******7
发帖数: 2506 | 40 用report比较多，觉得比较符合自己的思维方式。。。。 |
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o****o
发帖数: 8077 | 41 ZT from :
http://www.globalstatements.com/sas/jobs/technicalinterview.htm
*****************************************
SAS Technical Interview Questions
You can go into a SAS interview with more confidence if you know that you
are prepared to respond to the kind of technical questions that an
interviewer might ask you. I do not provide the specific answers here, both
because these questions can be asked in a variety of ways and because it is
not my objective to help those who have little actual int... 阅读全帖 |
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b*****o
发帖数: 817 | 42 一般来说，分类female or male,they are mutually exclusive,
但是其中有一个不是怎么办？比如并发症，有的人可以同时有好几个并发症。
这样的话，table怎么做呢？
这个table 具体来说是这个样子的
2000 2001 2002
black white black white black white
Gender
male
female
Comorbidities
diabete
asthma
obesity
具体来说应该怎么做比较好呢？用proc tabulate还是proc report好做？ |
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p***r
发帖数: 920 | 43 I was just wondering how, the two data are of two different sizes. |
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p***r
发帖数: 920 | 44 only want to output the first 10 levels with highest frequency. Can I sort
the class variable according to value/result of another variable ? |
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R*********i
发帖数: 7643 | 45 Not sure if I understand your question - proc report? |
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b*********l
发帖数: 466 | 46 Just want to produce a tabular table.
If use proc report. is there any options to add the tabular format? |
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x*****r
发帖数: 2404 | 47 直接export成excel行吗？
我其实没太听懂。 |
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x*****r
发帖数: 2404 | 48 直接export成excel行吗？
我其实没太听懂。 |
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l***a
发帖数: 12410 | 49 sas目前threads enabled procedure有
Base SAS engine indexing
Base SAS procedures: SORT, SUMMARY, MEANS, REPORT, TABULATE, and SQL
SAS/STAT procedures: GLM, LOESS, REG, ROBUSTREG.
我不确定它们是不是trivial的。。。我是现在的疑问是，按照前面那个paper的方法试
验，不管是不是threads enabled的proc在运行效率上都没有提高，那这些paper讲解的
什么 rsubmit/endrsubmit 有什么用
功能 |
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D******n
发帖数: 2836 | 50 pivot table 就是cross table +filtering
相當於SAS裏面的proc tabulate |
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