A brief numerical description of a set of data.

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19 views

How to find extreme values in a dataset in R? [on hold]

I have a dataset containing cities and their corresponding CO2 emissions. I want to find which cities have emissions too high or too low according to mean. Which functions in R can I use to find these ...
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3answers
58 views

Cohens d effect sizes

I'm using Cohens d effect sizes as a means of providing a magnitude based inference in a study I'm conducting. I just wanted to clarify if I'm correct here: Anything between .0 and .2 is small. ...
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0answers
11 views

Recover true statistics for a union of subsamples - only data available are summary statistics for each subsample

Let $a_1$, $a_2$, ...,$a_m$ be the samples of data, and let us further assume the only information we have about each sample is their count/no. of samples, mean, standard deviation and median. The ...
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0answers
19 views

Portmanteau test vs Breusch Godfrey test

I recently fit a VAR model to two time series and I was trying to check for serial correlation in my model. My main question is, when i use a function called serial.test in the R package, there are ...
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0answers
13 views

Summarizing output of moving correlation

I have 2 yearly time series (of 55 observations each) and I have calculated moving correlations between them (using windows of length 5 years). My aim is to summarize all the correlations I got into ...
2
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4answers
169 views

How to detect abnormality in an otherwise very systematic and regular time-series data for temperature measurement?

I have time-series data, let's say a pandas series, with time (sampling frequency is hourly) as its index and temperature measurement across that time. I want some statistical/time-series principle ...
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0answers
9 views

Calculate basic statistics for stream of binary data [closed]

I was reading this thread and started to think if there are any statistical tool to analyze binary data. I am mostly interested in the R project since it has good data-analysis tools for decimals ...
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0answers
9 views

Taming large datasets. How to keep historical data with aggregation techniques?

I will be collecting huge amounts of computer performance data and the datasets will get large very quickly. This necessitates reducing the size of the data by compressing the historical data using ...
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0answers
9 views

Statistic to summarise multiple timeseries observation with missing data

I have a data frame containing timeseries data on 200 patients ...
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2answers
67 views

How measuring the proportion of object in several classes?

I have 4 classes and I want to classify objects in each class. I have an arbitrary number of objects indexed from $1$ to $n$. My problem is, when $n$ varies, the proportion can change a lot. For ...
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0answers
10 views

How to find if any treatment is statistically better or worse in gene data given one standard method and 3 variations

Sorry I am a biologist and it appears am not quite confident enough for statistical analysis. I have datasets that represent different treatments on a biological system. It records how many genes have ...
2
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0answers
21 views

How do I calculate a t-score from a p-value (gain scores and N also available)

I have this problem that only the gain scores with the p-value of a t-test are given in a scientific article. The authors neglected to report the t-test statistic and I'm stuck on figuring out how to ...
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1answer
27 views

Scientific P Value with adjusted R Square [duplicate]

I am running Spearman correlation between 2 variables weight and freight both being numeric. The output I have received from correlation is P value - 0.00E+000 and Rank R Squared is 0.61 and which ...
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0answers
41 views

How to combine time series measured in multiple experiments?

I have recorded neural activity over time in mice while they perform a task. There are several mice, each ran different numbers of sessions, and repeated the task different numbers of times each ...
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0answers
23 views

Regression Analysis and Conditional Expectation

I have to calculate a Expectation of some expression conditioned on something. I know alpha, Beta1 and Beta2 in the below expression. Income and Family_Size are 2 Uniform Random Variables between 0 ...
2
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1answer
68 views

Is it possible to compute a correlation between two variables from just means, standard deviations and sample sizes?

Is it possible to compute the correlation between two variables with just the mean, standard deviation, and sample size? If so, how would I go about it?
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37 views

Market Basket Analysis

I am learning "Market Basket Analysis" and I need a clarification about Advantages and Disadvantages or Pro's and Con's of the "Market Basket Analysis". And some cases where actually this "Market ...
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0answers
22 views

Measure for comparing serial measurements of multiple variables in treatment vs control group?

Can anyone suggest whether I am going about the statistics in an appropriate way? I have two groups of populations which have similar characteristics. In each member of both groups, serial ...
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0answers
19 views

minimum sample size to estimate chi square population mean

Let's say I have a chi square population, I required to evaluate the minimum sample size to estimate the mean with confidence level 1-alpha, I remember that Confidence level calculation based on ...
0
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0answers
38 views

Combining multiple metrics to provide comparisons/ranking of k objects [Question and Reference Request]

Collecting $n$ metrics about $k$ objects Suppose I collect $n$ metrics about $k$ objects. I am looking into valid ways to compare the $k$ objects so they can be "ranked". I think this may be ...
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1answer
11 views

Allocating consumption to products

Following scenario: Data from 12 truck companies is available. For each company the absolute value of diesel consumption is available. Each truck company can ship Product A, Product B and Product C – ...
2
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1answer
20 views

How to display potential outage when usage fluctuates greatly among customers?

I work for a Health Information Exchange. We have numerous "participants". Some send hundreds of messages a day, some might go a day or two without sending any messages. I'm creating a daily report ...
4
votes
1answer
92 views

Log Transformation

I am planning to run a 2x2x3 repeated measures ANOVA on reaction time data pre and post treatment. However, my data is skewed and I wanted to do a log transformation but have few questions. Can I ...
0
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1answer
25 views

Meaning of a higher out-of-sample $R^2$ but also a higher MSPE

I am comparing several forecasting methods using the out-of-sample $R^2$ and MSPE. Now I have encountered situations in which the $R^2$ of a certain method is higher than that of the other, but the ...
3
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1answer
91 views

What's the meaning of dimensionality and what is it for this data?

I'm doing my assignment for my "Modeling and Optimization" course, and now I have doubts on the first question: What is the dimensionality of the data? What are the min, median, max, mean, ...
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0answers
10 views

quantiles over moving window

A subrutine of a computer library calculates the quantiles over fixed spaces for all of my dataset : eg it calculates: ...
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1answer
38 views

Analysing data from summary table on R (interactions)

If I want to test whether data[,1]:setB is equal to 0 or not, do I just use the given t value and p value or do I need to add it with the data[,1] values? looking at the p value of data[,1]:setB, I ...
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1answer
34 views

Rewriting RegressionSS

I am having troubles in deriving the RHS of this formula: $$RSS= \hat{\beta}^{T}Z^{T}y-n\bar{y}^{2}$$ where $Z$ is the design matrix I am given ${y}^{T}y$ (what exactly does ${y}^{T}y$ stand for and ...
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1answer
51 views

How to rank monthly data, using both trends and averages

I have a very large data set containing the daily searches for some Wikipedia entries. I am using the number of searches as proxy of popularity and want to rank the entries. Lets say I have entities ...
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0answers
38 views

Quantifying how uniformly spread out points are?

I'm looking for a way to quantify how "clumped" vs homogeneously/uniformly distributed points are in a graph. Each collection has 100 points as (x,y) pairs. I've attached two graphs as an example. ...
0
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1answer
100 views

De-normalizing Google Trends data?

Does anybody have suggestions on how to de-normalize Google Trends data? The site says that their trends are made with the following metric: The numbers on the graph reflect how many searches ...
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0answers
12 views

Statistical Comparison of two different waves

I have two waves data for a couple of cities and I need a comparison W I W II City A 10,000 10,100 City B 200 202 City C 1500 1515 There is a 10% increase of ...
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0answers
40 views

Averaging standard deviations of unequal weight?

I'm sorry if the title is unclear, but I'm not sure of the appropriate way to phrase this question. I'm in med school (and sadly not as versed in statistics as I ought to be), and I am trying to use ...
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32 views

Descriptive and Inferential Statistics

I am doing a time series analysis (stock market returns) and I am currently looking at the summary stats. I know the definitions of the individual stats but the one I am stuck on is the relationship ...
3
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1answer
291 views

Using a rolling window in time series regression

I am learning about regression. I have done some cross sectional regressions which are fine. I recently did a simple time series regression. So I have a y & x vectors each containing 1000 ...
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0answers
60 views

Is there a name for this sort of plot? Is there any reason not to use it?

Suppose we have some time series data, with multiple samples per time unit. For example: ...
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1answer
103 views

How to compute the pdf analytically for the sum of generalized gamma

Question: problem statement $$z^d = \sum_i x_i^d $$ pdf of $X = \frac{d(\lambda x^d)^n}{x \Gamma(n)} \exp(-\lambda x^d)$ which is a generalized Gamma distribution and they represent euclidean ...
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3answers
67 views

interpret scatter plot if there is anything to interpret from it

I have an x variable and a y variables. I have done a simple scatter plot. I however don't really know how to interpret (if there is anything to interpret) the plot. I can't find any other similar ...
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0answers
60 views

MECE statistics

Consider a sample of a real quantity $X$. Say that we divide this sample into two mutually exclusive and collectively exhaustive (MECE) groups. Say we know the mean and median of these two groups, ...
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1answer
63 views

A Simple Regression Model for Our Experiment? [closed]

We know, In statistics, simple linear regression is the least squares estimator of a linear regression model with a single explanatory variable. In other words, simple linear regression fits a ...
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0answers
21 views

How to show ancillary statisitc of normal random sample?

Let $X_i \sim N(\mu,\sigma^2)$ and $X_i$ are independent. Then how to show that: $$ T = \left(\frac{X_1-\bar{X}}{S},\frac{X_2-\bar{X}}{S},\ldots,\frac{X_n-\bar{X}}{S}\right) $$ $T$ is an ancillary ...
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1answer
29 views

Suggestion on algorithm to visualize the safeness of an area [closed]

I am actually developing an app that notify users about "Safety Index" of the surrounding in a range of 1 Kilometer radius. I have did some research on how to calculating crime index which uses the ...
5
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0answers
155 views

A tricky question about correlation [duplicate]

$X$, $Y$ and $Z$ are three random variables where their pairwise correlations are the same, i.e., $corr(X,Y)=corr(Y,Z)=corr(X,Z)=\rho$ what are the possible values of $\rho$? I was asked this in an ...
0
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2answers
31 views

Would this situation be a ratio of 1/5 or 1/10?

Hypothetical situation that I'm trying to use for understanding some criminal statistics. Let's say there is a city with 10 banks. One criminal robs two banks before being arrested and placed in ...
1
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1answer
103 views

assumptions made for a normal distribution- a interview question

I was asked in my interview: What assumptions can you make? Why and when? (i.e When is it safe to assume "normal"). Can some one answer this .
9
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1answer
162 views

When would we use tantiles and the medial, rather than quantiles and the median?

I can't find definitions for either tantile or medial on Wikipedia or Wolfram Mathworld, but the following explanation is given in Bílková, D. and Mala, I. (2012), "Application of the L-moment method ...
2
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1answer
41 views

Is this a valid use of “positive predictive value”?

So here's your typical table for evaluating the performance of a diagnostic test: Gold standard result ...
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0answers
28 views

What effect do outliers have on standard deviation and the IQR?

I understand that they will both sorta increase, but if i remove them how will the bulk of my data change? for example in a boxplot/ histogram
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0answers
22 views

How to find the probalities of a,b,c (mutually exclusive events) when i turn the problem into three binary classification problems?

I am using scikits linear logisitc regression to classify three events a,b and c. it works better (score) when i convert them into a binary classification model. such as: 1. M1 classifies a or b 2. ...
4
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0answers
133 views

Caclulating standard errors for generalized least squares without raw data (just sample means and covariance)

I have a question very similar to the question asked here: is it possible to calculate standard errors (specifically, the standard error of the intercept) for generalized least squares regression ...