Questions tagged [aggregation]
Refers to "lumping together" potentially inhomogeneous groups of data.
0
votes
0answers
20 views
Machine-learning using an aggregation function
I am looking for a machine-learning algorithm (ANN, random forest,...) that is able to account for an aggregation function during the learning step.
I want to estimate variable Y from variables X1,X2,...
0
votes
1answer
18 views
Multiple data points per subject? Aggregation to mean with or without considering subjects
I am currently arguing with someone on how to correctly treat data with multiple observations per subject. More specifically data was gathered from 100 participants 8 times per day for 5 days (...
0
votes
0answers
33 views
Is it valid to get the average of the corresponding elements of two time series?
Say I have two time series that have the same length within the same time period. I need to replace the two time series with a single time series that explains the variations in both. So what I ...
0
votes
0answers
26 views
True Mean of an Observation
I have a list of aggregated data with 100 data points. The information I have is the mean and the number of observations used to calculate the mean. Moreover I have the raw data from which the ...
0
votes
0answers
22 views
Recommended model to analyze relationship with aggregate rate
In order to analyze the relationship between some independent variables and a binary dependent variable, it is standard to use logistic regression, which allows us to model the probability of the ...
0
votes
0answers
39 views
What is the effect of different goalposts values on MinMax normalization of composite indicators?
I want to compute a synthetic index based on several indicators for one country on a time period.
The indicators have different ranges and units. I want to normalize them using a MinMax ...
0
votes
1answer
41 views
Aggregation of “tree results” in random forest regression
I would like to know how the results of different decision trees are aggregated (average) in random forest regression.
If I have a numeric target variable and 10 predictors, each decision tree is ...
2
votes
0answers
39 views
How to aggregate histograms for density estimation
Within a very large sensor network, each node does take measurements derived from a fixed number of samples taken at a high frequency from an instrument. The number of measurements send to an ...
0
votes
1answer
48 views
Machine Learning model with aggregated data as training
I would like to predict a LABEL: A,B or C using a classification machine learning model.
My data to train the model is like:
...
0
votes
0answers
28 views
Are estim. coef. and R-sqrd expected to change at different levels of aggregation (hierarchical data)?
I am working with hierarchical data and I want to estimate the same model (y=a+xb) at different levels of aggregation. For example, the first model (m1) uses individual data, the second model (m2) ...
-2
votes
1answer
38 views
Aggregating Cluster Analysis Results [closed]
I want to write something about cluster analysis. I have started to read something about it and I faced with a concept which is called ''Aggregating''. What does it mean for cluster analysis? Do I ...
2
votes
1answer
29 views
Aggregation of overlapping intervals
Hello anyone and everyone,
I have a data set of traffic flow data, particularly intensity data. I have the traffic counts per minute as the base data and then I am aggregating them into 3 and 5 ...
0
votes
0answers
20 views
Combining distributions
I have a ruler and a set of poles $S$. My ruler is not perfect, so a length measurement of one pole yields in fact a sample of a probability distribution (e.g. natural scientists usually find normal ...
0
votes
0answers
22 views
Is there a theoretical justification for the idea that aggregating time series data leads to better forecasts?
In retail demand forecasting, we often resort to aggregating data across product or location hierarchies to obtain more accurate forecasts.
I understand the concept intuitively: You have a better ...
0
votes
0answers
17 views
Difference-in-Differences: y variable as quantity at monthly level
I want to estimate a difference-in differences equation with the following "background story": I have a data set of apartment listings for the months of November 2014-November 2017. Some of the ...
0
votes
0answers
21 views
Aggregate Data from Unequal Sample Size
I need to aggregate land price data from several station areas for a later regression analysis. However, each station area has different sample size and total area.
...
0
votes
1answer
209 views
How do I aggregate percentiles from previously aggregated percentiles?
I have previously aggregated data for every 5 minutes with a count of sensors at that location and 5% percentiles of a value of interest: 5th, 10th, ..., 90th, 95th. A sensor can have multiple ...
0
votes
0answers
30 views
Linear Regression: Different levels of aggregation for different variables
I have the dataset with different levels of aggregation for different independent variables. E.g.:
Var.1, Var.2 measured per SKU
Var.3 measured per Brand (couple of SKUs)
Let's say I want to predict ...
0
votes
0answers
25 views
Time Series Data: Unequal Sample sizes
I have a dataset which consists of daily observations over a 3 month period for different variables. The data are aggregated so I do not have access to user level data.
The problem is that the ...
3
votes
2answers
77 views
Aggregate repeated measures data or model it?
The structure of my data is causing me some trouble because I'd prefer to aggregate it but I'm not sure of the implications.
It's from an experiment comparing dwell time. The subjects were randomly ...
2
votes
1answer
55 views
Forecasting proportions of aggregations vs direct forecasting
Assume one has to predict the sales of a shop on a daily basis. The sales per day $S(t)$ clearly follow a strong weekly pattern, but also a yearly pattern, a general trend and of course some noise are ...
1
vote
1answer
25 views
How to summarize items and still calculate percentiles?
My company wants to track request latencies for the project I'm working on.
Specifically, the report I'm building should have the 95th and 99th percentile values of the latencies over all events.
...
3
votes
2answers
37 views
Many samples of the same identity for machine learning
This seems to be a simple question, yet I couldn't find a clear answer on the net.
I'm using machine learning to classify ill/healthy patients based on their medical record (probably using a Random ...
0
votes
1answer
25 views
Feature selection: Should we keep all metrics (like mean. median,..) of a distribution or they make redundant features?
There are many cases in which I don't know which metric I should use to calculate the value of a feature when the value has a distribution for each data point instead of an absolute number. for ...
0
votes
0answers
21 views
Calculate a Margin of Error for a Re-calculated Median from aggregated ACS data
I am trying to create a function in R to calculate the 90% MOE for a re-calculated median from aggregated ACS data. The steps to do this are described here and I was able to find a custom function ...
1
vote
0answers
25 views
OLS difference between individual level and aggregate level estimates
I am new here, so please accept my apologies if this does not belong here.
My question essentially concerns what appears to me a special case of the ecological fallacy. Consider a simple model that ...
0
votes
0answers
13 views
Chi-Squared test (for proportions) with data aggregated across time — dealing with possible correlation
I have a question regarding how best to use the $\chi^2$ test with aggregate data.
To give you an idea of what I'm dealing with, here is a concise list of facts that I think you will need:
Suppose ...
2
votes
0answers
17 views
Fuzzy Aggregation
Each observation in the data consists of a binary outcome variable $Y$, a set of labelled measurements $(M_1,L_1), (M_2,L_2)...$ (the set size can vary between observations) where each label is one of ...
0
votes
0answers
3 views
Is it possible to update an aggregated dataset by changing the reference group by which an indicator is mesaured?
I have a publicly available dataset that I am using for a project. The data is aggregated on the neighborhood level and the data is originally from the US Census.
The data I have from this dataset ...
0
votes
0answers
9 views
How to compute the aggregate response in a panel
I have a panel where I can measure the causal effect of changes in $x_{it}$ on outcomes $y_{it}$. If $i$ indexes sub-national units, like states or provinces, then can I then use the local estimates ...
0
votes
0answers
18 views
How many quantiles to use when estimating the parameters of a distribution from a large sample
I wish to estimate the parameters of a member of a specified distributional family with CDF F(x) by using the quantiles of a large (tens of thousands) sample drawn from that distribution and a GMM-...
0
votes
0answers
12 views
Need advice aggregating data for computing correlations between variables given by dataset
I am trying to find correlation between Opioid Severity and Employment Statistics. I don't have access to my professor right now.
So I have 2 datasets. 1 dataset measures Opioid concentration (...
1
vote
0answers
54 views
Calculating/Averaging/Aggregating Effect Size Across Multiple Measurements
What is the standard practice for calculating a total effect size (using Cohen's d) across multiple measurements in one study? Do you calculate the effect size for each measurement and then take the ...
1
vote
0answers
276 views
R mlogit and McFadden R^2 (strange?) value
I was a little bit surprised by the high value of the McFadden R^2 given by the "mlogit" R package for this simple model:
f = mFormula(mode ~ log(cost) | 1 | 1)
...
0
votes
0answers
13 views
What can I put instead of missing value in variable that represents maximum of lab tests
I have a data set which includes a lot of variables that are basically an aggregated function over the years of the study. Each row represents a patient, each column a measure. The study period is 4 ...
0
votes
1answer
29 views
Summarise data with R - other than n counts [closed]
I've got donor segments
Donors aged 34 and younger, vs. donors aged 35 and older
Donors with a high frequency of donations vs. donors with a low frequency of donations
Every row in my data frame ...
0
votes
0answers
24 views
How can I understand influence of individual observations on an aggregated total?
**Background: ** I'm trying to understand what is driving an increase or decrease in the total insurance claims spend for a given month compared to last month. I can look at some specific measures ...
0
votes
0answers
33 views
What test to use for aggregate and cumulative data?
I am exploring the role of social media on voting/voter registration for millennials (18-36) and those 37-65.
I have us census bureau data that provides cumulative data by age on voting numbers and ...
3
votes
0answers
48 views
Is it dangerous to take the mean of ratio measurements?
I'm going through a Computer Architecture course and in one of the lectures they mention that when measuring the difference in runtime performance between two systems, using for example multiple ...
0
votes
0answers
34 views
Sum of correlated time series
I have some time series, for which I have point and density forecasts - i.e. I have confidence intervals. I'd like to sum those. Summing the point forecasts is trivial, but I'm not sure how to sum the ...
4
votes
1answer
564 views
Regularized GLM with aggregated data
I am fitting a poisson GLM to model claim rates. Since I have 1.5m+ records, I have aggregated my data (to improve efficiency). My understanding is that using aggregated data with a poisson GLM will ...
1
vote
0answers
157 views
Aggregating normalised data
I want to aggregate Google Trends data relating to separate queries that share a thematic category - e.g. "beer" and "wine". I don't care about the relative popularity of the terms - it is more ...
0
votes
1answer
42 views
Averaging bang for the buck
I'm building a table/graph to compare multiple video cards according to a given benchmark.
The benchmark consists of multiple measurements using games. For each benchmark measurement, I build a ...
1
vote
0answers
62 views
When is it appropriate to pool trials within subjects for statistical comparisons?
Usually I have small number of subjects (e.g., 4-6 rodents) and I record electrophysiological activity during presentation of a stimulus or performance of a task. A general question that arises when ...
0
votes
0answers
29 views
Aggregated Means Differ in Regression
I try to run a difference-in-difference model based on single observations which I have to aggregate in order to generate an outcome variable "w.mortf" = mortality.
My original data set provides a ...
3
votes
1answer
50 views
Privacy through moving averages?
I am considering the following hypothetical situation: I have a time series of data. In general, 'the public' should have access to features of this data. However, making the time series available ...
0
votes
0answers
33 views
Can i treat Asselin 2002 linear categorical composite indicator of multiple correspondence analysis as a geometrical function as in OECD 2008?
in Asselin (2002) http://www.ipc-undp.org/conference/md-poverty/papers/Louis-Marie_.pdf , the expression of the categorical composite indicator of multiple correspondence analysis (qualitative ...
2
votes
1answer
91 views
Linear regression on aggregate and missing data
I have data from a survey with $m$ quantitative questions (rating 0 to 100). There was $n$ participants. I want to apply linear regression to predict $X_m$ based on $X_1,\dots,X_{m-1}$.
There are, ...
-1
votes
1answer
26 views
How to represent multiple data by single value
I have three inputs x1,x2,x3 and to each single input there are three outputs y1, y2, y3.
(1) x1 --y1, y2, y3
(2) x2 --y1, y2, y3
(3) x3 --y1, y2, y3
The Whole whole set has to be represented by ...
0
votes
1answer
70 views
Is it good statistical practice to include an “aggregated” categorical variable in LM?
I am dealing with a large data set (~100000 observations, roughly 13 variables). Most variables are of categorical nature and are stable across different observations concerning the same individual/...
