# Questions tagged [data-analysis]

Questions on the use of mathematical techniques to extract properties from given data. Consider if your question might be more suited for Cross Validated (stats.SE) instead.

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### Time series analysis on ACF and PACF plots

So I have a non stationary time series that is hourly, daily and monthly recorded for a year and I have the ACF and PACF plots for the serie. ACF and PACF I applied the the Ljung-Box test and for ...
1 vote
12 views

### Graphical model - log transformed covariance matrix

It is known that the non-zero entries of the inverse covariance matrix constitute an estimate on the edges in a graphical model. I wonder if there is an analog or similar result for the log-...
40 views

### OEIS Previous version [closed]

I am interested in downloading the OEIS of some previous versions. In order to do some data analysis and compare it with today's OEIS. Does anybody know how to download or create a subset of the ...
21 views

### Calculate the expectation and variance for normal distribution [closed]

I am solving a question which is about distribution but it is confusing as I am new in the course of applied data analysis. how we calculate the expectation and variance when we have this given ...
11 views

### Mini batches and loss in recurrent neural networks (RNNs)

Suppose that we have a sequence $\left\{x^{(k)}\right\}_{k = 1}^{N}$ and that we wish to use a RNN to predict the next element of the sequence given the previous elements of the sequence (e.g., a ...
22 views

### Statistics confidence interval when I know the data is always positive [closed]

I have a data set where most of the data is close to zero, but there are some considerable outliers. The data is all ratios of positive numbers, so I know none of them will be negative values, but ...
27 views

### How can I express a lower order partial differential equation (with regards to the variable I want to focus on) as a higher order order PDE?

I'm currently researching a data driven algorithm and I want to express the PDE results in a different manner. This is the kind of form I would like to get, mostly I want to express the t partial ...
84 views

20 views

### Best way to standardize data set that have a variety of ranges that update over time

So I have a fairly unique scenario, the following is currently the format of the data and how it works: Each column of data can contain a variety of ranges, i.e. one columns may contain values from -....
48 views

### How to evaluate the difference/distance between 2 values positive and negative on a scale

Problem 1 : The input is 2 values, that can be in a scale between [-3.89, 10.66] And i need to compare the difference between an oldValue (A) and a newValue (B). So i want to create a variable that ...
54 views

### Creating a probability density function for a particular dataset [closed]

I want to create a probability density function for a particular dataset. First of all, I calculate the mean and the variance of my dataset. So, I use the mean and the variance to create a probability ...
18 views

### Calculating stock returns?

I am currently working on a project to analyze the stock data and predicting future stock prices and if possible building strategies to trade in the future. I just want to know the difference between ...
6 views

### Posteriori of latent factor model

I'm reading this article https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3419391/. I want to compute the posterior distribution of the factor latent model. The generic form of a latent factor model is  ...
19 views

### Weighted averages for microdata merging

I'm working with microdata files and would like to hear if any one may have a suggestion when merging the data. I'm concerned with making inferences on wages given specific character traits. I think I ...
65 views

### What is a dimension of a convex hull?

Let $S$ be a set of data points in $E^d$, a real Euclidean space of dimension $d$. What would be the dimension of the convex hull of that data? In general, what is the definition of the dimension of ...
13 views

1 vote
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### "F1 score better" equivalent to "accuracy better"? Or not?

I have been asked to proof: Suppose we have two models, $M1$ and $M2$, that solve the same binary classification problem for which we compute the $F_1$ values and accuracies. I have been asked to ...
21 views

### Internal covariance matrix of linear fit

In a physics course, I learned about the covariance matrix. It is defined as follows: Consider a dataset $\{\{x_1,y_1,\sigma_1\},\dots,\{x_n,y_n,\sigma_n\}\}$. Here the $x_i$ have negligible ...
1 vote
93 views

### Histogram and Normal distribution

I was studying histograms and normal distribution. As far as I know, they are two different tools used for calculating probability and statistics. More specifically they help to visualize and it is an ...
1 vote
I have a question regarding the the term in the acceptance ratio of the Metropolis-Hastings algorithm (Refer to the link to a screenshot). Is the $\mid$ in $g(x_t \mid X^*)$ supposed to mean it's a ...