y*****w
发帖数: 1350 | 1 (1) This is a "crossover ANOVA" which involves the feature of paired t-test.
It is exactly in the process of estimating "standard deviation of
differences" which involves the STDDEV of difference in AB, the STDDEV of
difference in BA, and the between-subject correlation between AB and BA.
(2) On the other hand, when directly applying paired t-test, we would need
to input the STDDEV of A, the STDDEV of B, and the correlation of within-
subject pair of measurements. See the link at
http://support.... 阅读全帖 |
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q**t
发帖数: 36 | 2 Hi All,
I am using lme in R to estimate standard error the random effect.
The output of the StdDev of lme is the SE of the random effects?
lme(y~1, random = ~1| s/p/k )
Random effects:
Formula: ~1 | s
(Intercept)
StdDev: 0.02100801
Formula: ~1 | p %in% s
(Intercept)
StdDev: 0.001980935
Formula: ~1 | k %in% p %in% s
(Intercept) Residual
StdDev: 0.01581869 0.006076241
Number of Observations: 240
Number of Groups:
s
5
p %in% s
... 阅读全帖 |
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t*****z
发帖数: 1598 | 3 请问大家：我现在不得不需要手工处理qPCR数据。已知实验组（1）的Ct与Stddev，和
内对照（0）的Ct与Stddev，计算实验组的相对数量，用公式exp(-Ct1)/exp(-Ct0)（不
知道对不对？），可是这个算出来的值，它的标准差又怎么计算呢？多谢多谢！大家周
末愉快！ |
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I***a
发帖数: 704 | 4 我在最坏的那个coner下做monte carlo analysis， 变化选的是mismatch,
10，000点出来的测量结果里有 max, min， average, 还有stddev.
请问pass是指average > threshold, 还是min > threshold， 还是 average-3*stddev
> threshold?
谢谢。 |
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S*******e
发帖数: 525 | 5 我们有一个问题是探测无线通讯中的‘Sleepy Site'. 其定义类似于一个site在一段
时间内不能接通信号（按次数算）。可很多时候，根本没有信号（通讯）需要一些
sites来处理。 从数据上看，通讯次数都是0. 譬如今天有一个时段我们发现某个site
有零
次信号，我们要根据过去十周同样时间的数据来断它是真的没有‘任务’，还是它‘睡
觉了’。
因为数据是离散的（次数），这显然是普耳松分布， 实际数据按照不同的时间，不同
的地点，从0 到几个次数， 甚至到2，3百次。 我们的主任提出的算法是 -- 按正太分
布算，如果0在mean-3×sigma之外，就算睡觉了。 Confidence 用 P=100%- NORMDIST(
0,mean,stddev,lowtail)算。 可这究竟是什么东西，我觉得太不好解释了。 首先，
不管这个P是什么，如果过去十周的数据每周次数都很少，像 7，8 个，我们就不能用
正太分布算。 实际上，0次数的概率是不是就是e^(-mean)（因为这是普耳松分布）？
其次，虽然当次数都是很多的话，可按正太分布算， 但NORMDIST(0,mean,stdde... 阅读全帖 |
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x******a
发帖数: 6336 | 6 怎么算中等偏上？
中等是什么定义的，中值还是均值？
偏上“一点”是多少，几个stddev？ |
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s********n
发帖数: 1962 | 7 ☆─────────────────────────────────────☆
scarface (人生犹如一场电影) 于 (Sat Apr 19 15:42:21 2008) 提到:
发信人: scarface (人生犹如一场电影), 信区: Stock
标 题: Value stock that's cheap now
发信站: BBS 未名空间站 (Sat Apr 19 15:30:00 2008), 转信
I found the following stocks that meet the following conditions:
1. Very stable earnings (defined by low stdDev)
2. Most recent quarter earning do not have large negative surprise
3. current P/E was recently (9 month) trading 30% lower than 7-year average
of
the stock, and is currentl |
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s******e
发帖数: 696 | 8 I found the following stocks that meet the following conditions:
1. Very stable earnings (defined by low stdDev)
2. Most recent quarter earning do not have large negative surprise
3. current P/E was recently (9 month) trading 30% lower than 7-year average
of
the stock, and is currently trading at least 15% lower than 7-year average.
(I use my own calculated P/E which is adjusted by Dividend factor).
4. no large insider selling recently
5. Stock historicaly was not trading at high P/E ratio (not |
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d**u
发帖数: 1065 | 9 可能tsc有更多被遗忘的case吧。看来还得统计个stddev才靠谱。 |
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a*****o
发帖数: 209 | 10 Income is most likely a power law distribution. Avg and stddev are very
biased in such case. That's why you only see medians being reported in most
income related stats. |
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t*****g
发帖数: 1275 | 11 这样的话，可以试试groupby A，然后把能算的aggregation result都算一算，比如
count，avg，max，min，stddev之类的，也算是pseduo hash了八。倒是要自己review
最后结果的。 |
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z*****n
发帖数: 7639 | 12 【 以下文字转载自 Software 讨论区 】
发信人: zhaoyun (好德如好色), 信区: Software
标 题: 问个画图的问题
发信站: BBS 未名空间站 (Mon Aug 15 11:42:56 2005), 站内
发信人: zhaoyun (好德如好色), 信区: EE
标 题: 问个画图的问题
发信站: BBS 未名空间站 (Mon Aug 15 10:55:19 2005), 转信
用什么软件可以画那种带stddev垂线的图？
excel好像不行。 |
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B*****n
发帖数: 498 | 13 My focus is to compare two sample means.
Here is how I use PROC POWER
proc power;
twosamplemeans
meandiff = .
sides = 1
npergroup = 7 14 21
stddev = .1
power = .8
alpha = .1;
run;
The result is:
The POWER Procedure
Two-sample t Test for Mean Difference
Fixed Scenario Elements
Distribution Normal
Method Exact
Number of Sides 1
Alpha 0.1
Standard Deviation |
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w********u
发帖数: 328 | 14 I want to calculate the POWER.
SAS code:
proc power;
onesamplemeans
mean = 8
ntotal = 150
stddev = 40
power = .;
run;
This method makes sense when it follows normal dist., but my case is that
the sample size is extremely small but the population is very large, i can't
say that it follows normal dist., i assume it doesn't follow any particular
dist. but i haven't got the data yet, i wonder which method could be used
in this case and what's the sample size needed to conduct any analysis. for
examp |
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s******s
发帖数: 145 | 15 有两组数，两个mean,只知道下面四个值
N1=1000, mean1=12
N2=1010, mean2=10.5
用哪个test可以来看看mean1和mean2是不是significant different? 还是说条件不足
， 需要知道StdDev什么的。
晕了
第一个给出正确意见的发5个包子 |
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i****e
发帖数: 151 | 16 一个TIME SERIES,要画各个TIME POINT的MEAN和STD DEV，CONNECT ALL MEANS.
有两个CATEGORIES,，所以两条线
我知道可以用MEANPLOT的PACKAGE，但是两个CATEGORIES 在每个时间点都是重合的，所
以看不清楚STDDEV。我想让两个错开一点。不知道怎么最简便？最好有MACRO。
感谢！ |
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