# All Questions

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### CNN and kernel sizes: is upsampling useful?

I am playing with Deep Recurrent Q-Network in Reinforcement learning. The architecture I am currently using is similar to the one presented in "Human-level control through deep reinforcement learning"...
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### Need help in understand the histograms?

Below graphs are birthrate, deathrate, population and population_growth of all the countries in the world. I don't know how to clearly understand these plots. I don't know what are xaxis and y axis ...
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### How can use UDF function in outside of function

I have created UDF Function in R and I want to apply that function in Outside the function, please help me is it possible to do it ?. please explain me to give some example. Thanks Dev
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### Faster RCNN - Pyramid of Filters vs Pyramid of Anchors (Reference Boxes)

I'm reading faster RCNN paper now and trying to understand what is the difference between Pyramid of Filters and Pyramid of Anchors methods from the scale point of view. I mean if I use only one ...
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When we set a batch-size, after each sample of batch passed we take the gradient but wait until last sample of batch to passed and then propagate the sum of gradient of them through the network? Am I ...
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### reporting beta coefficient for chunk tests in logistic regression

I have used lrm in the RMS package to construct a logistic regression model with several interaction terms for a recent paper. As part of my strategy, I decided to use Wald Chi-squares on factors ...
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### How to forecast a time series in R with ts()

For June 2009 - June 2018, I have prices for product to be delivered that month if bought on the date on the left most column. This below is an excerpt to show the format. The 1-5 and so on r between ...
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### Using probit regression coefficients to derive probabilities?

I'm reading a paper here that uses a Probit Regression. I'm not entirely familiar with how this works. But, I'm wondering if there's a way to use the coefficients from Table 3 to derive the ...
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### What is the difference between Silhouette Index vs Dunn Index vs Davies-Bouldin Index

I would like to know whether there is any condition that using one cluster evaluation methods (Dunn, Silhouette, Davies-Bouldin) is better than others. I didn't find anything online or inside books, ...
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### Calculating the 1 Sample Kolmogorov Smirnov Test Statistic for Normality

Can anyone give me some insight into where this calculation for the KS test statistic is going wrong (see figure 1)? I ran the test in SPSS and SAS as a check. I have used the same process for other ...
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### How to create a binary threshold from Cosine distance between 1-D arrays?

I have a graph of the Cosine distance between the question and the sentence most similar to it when there is an answer and when there is none. I want to establish a threshold on the abscissa axis ...
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### covariance of longitudinal measures under random intercept/slope model

I am considering a model where I have repeated/longitudinal measures over a number of timepoints from baseline (probably evenly spaced - perhaps with 2 groups) and I assume a random intercepts and ...
6 views

### Running analyses with uneven group sizes

I was trying to run a study with 100 people per condition for 4 conditions. When I looked at the results, the group sizes were skewed - some had 80, some had 120. If I'm planning on running a series ...
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### Merge two datasets with different units of measurement

I have two physiological data sets coming from two different populations entering the same experiment which includes two IV; Drug vs Placebo (2 level; between-subj) Stimulus type (3 levels; within ...
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### Intuitive explanation of the Wald Chi-Squared Test

I am having trouble understanding what the Wald Chi Squared test is used for intuitively. SPSS uses the Wald Test (type III) in the "Tests of Model Effects" box when I run my GEE models, but I don't ...
19 views

### Random Forests and Information gain

Suppose you are building random forest model, which split a node on the attribute, that has highest information gain. In the below image, select the attribute which has the highest information gain? ...
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### How to weight features when doing text mining?

I have a case where I'm doing text mining over a list of product titles. In particular I want to run a clustering algorithm. But I also have some information about those products that I think can add ...
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### Wind (speed) - a non-iid random variable?

Over a time period of 1 year, half hourly wind speed data is collected. Is it false to state that the collected data is not-iid? I know that wind is seen as a non-stationary process, but does it also ...
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### In multivariable quantile regression, how can we determine which observation corresponds with a particular quantile?

I'm trying to use quantile regression to solve an areal interpolation problem as described in this paper: https://www.tandfonline.com/doi/abs/10.1080/00045608.2011.627054 Basically I have a set of ...
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### Classification accuracy on multi classes

My target has 5 classes. My testing dataset has an accuracy of about 34%. Can I assume this is a reasonable model purely based on classification accuracy, since random guessing is 20%.
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### Improving spam classification with tensorflow logistic regression

I would like to classify a mail (spam = 1/ham = 0), using logistic regression. My implementation is similar to this implementation and using tensorflow. A mail is represented as a bag-of-words ...
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### From OLS to semi-parametric GAM: parametric vs no-parametric

I am quite new to this kind of topic, but for my master thesis i built an multiple linear regression with OLS. Now I want to control for non-linear relationships using a semi-parametric GAM. My ...
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### How to use the T-test for the performance of survival time prediction?

I used 2 methods to predict the Survival time of patients. I used the Concordance index (C-index) to evaluate the performance of prediction. I wanted to test if the prediction performance for the ...
91 views

### Can PMF have value greater than 1?

Can a Probability Mass Function can have value greater than 1 like we have in Continuous functions(pdf) and why? Please give 1 example if the answer is yes. And If the answer is no then why PDF can ...
6 views

### Analyzing behavioral change: Comparing 2 measured weight curves to a model curve

I'm currently in the process of analyzing experimental data and would like to hear your opinion on the method I would like to use to test my hypothesis. I had an experimental setup where I recorded ...
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### Similarity between Train and Test data sets

I have multiclass classification dataset and I am using Deep nets for the classification task. To explain the problem, let's assume that I have 5 classes to classify. No matter what I try, be it ...
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### Dependent variables with values on a (likert-type) scale

we'd like to conduct a study about the perceived valuation between two persons (let's say A and B that have different characteristics). Therefore, for our dependent variable, we'd like to ask ...
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### Cox model with a predictor variable within only one stratum

I'm investigating survival in a cancer patients cohort. The Cox model I'm using is stratified by stage and adjusted for several variables. I would like to add one variable RT (Radiotherapy) which is ...
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### How to uniquely identify each Employee in an Organisation with a hash value between 0 and 511 [on hold]

let I be a set of random input values, with I = N . Then h meets this quality criterion if (∀1 ≤ i ≤ n)(|h(I) ∩ Pi| ≈ N/n ) if N >> n. Suppose you want to use Employee numbers to calculate a hash, ...
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### Algorithms for everyone [on hold]

Something I've allways wanted to see is a concise run-through of different machine learning algorithms, all on one page: With their pros and cons, what situations they work in best and when they don'...