# Questions tagged [computational-statistics]

Refers to the interface of statistics and computing; the use of algorithms and software for statistical purposes.

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### Adding very small probabilities - How to compute?

In some problems, probabilities are so small that they are best represented in computational facilities as log-probabilities. Computational problems can arise when you try to add these small ...
1answer
99 views

### Pearson correlation in data set with “jump”

I'm trying to calculate the correlation between the condition number of a finite elements matrix and the coarseness of the mesh that it represents. However, when trying to calculate the Pearson ...
0answers
166 views

### How do I measure information loss when converting categorical data to numerical?

Assume that a dataset has a mix of categorical and numerical attributes. The dataset has to undergo numeric processing which necessitates the conversion of the categorical attributes to numeric/...
0answers
21 views

### Suitable multiple testing procedure for three very correlated phenotypes

I have ran an analysis using polygenic risk scores including genetic variants at different p-value thresholds and have the following outcomes: IQ ages 8 and 9, strengths and difficulties questionnaire ...
2answers
97 views

### SPSS Statistics

The variance measures how far each number in the set is from the mean I have 151190 records of a table. and i have to analyze the data on SPSS. after the analysis i have some results. Mean=74617.92 ...
1answer
77 views

### Rules based Model (Function) - Derive Probability & Ensembling

Basically, let's assume I have a simple rules-based function/model (if weight >= 150) -> return true. Simple binary answer (true or false) from a single feature input. If I have a range of samples/...
2answers
418 views

### Evaluating the hazard function when the CDF is close to 1?

I need to evaluate a hazard function $h(t;\theta) = \dfrac{f(t;\theta)}{1-F(t;\theta)}$, where $f$ and $F$ are a pdf and a cdf, respectively, at many values of $t$ (and for several values of the ...
1answer
234 views

0answers
19 views

### Data Correlation for computing software metrics

I have the below sets of data per application, you can call them as software metrics. These metrics vary depending on the size of an application. ...
1answer
91 views

### interpretation of this interaction

I am looking for help with the interpretation of a complicated interaction term. I am using a fixed effects model. The interaction term is: Code: ...
1answer
82 views

### Computing new variable of nominal and scale z scores variables

I'm analyzing a set of data where participants' reaction time and number of errors made during the task were measured. As there were two trials (where same data was measured) I was thinking I could ...
1answer
1k views

### Functional Principal Component Analysis (FPCA): Mean Function

How does one calculate a mean function in Functional Principal Component Analysis (FPCA) given a data set with an unknown distribution? (A theoretical approach if possible) I am wanting to implement ...
2answers
873 views

### Extracting power of a power law from data

My question is more about the methodology. Assuming in some experiment we have measured quantity $y$ per each unit of time $x.$ So $y$ and $x$ form our data set here. Moreover, we know that they are ...
1answer
791 views

### Why is L-BFGS optimization faster when binary features have been standardized?

I have a question related to standardization of binary features within a regularized logistic regression. Suppose that you have a model where all the features are binary (the result of applying the ...
1answer
416 views

### sampling from an unnormalised distribution

If one has to sample (with replacement) from a population $(x_1,x_2,\ldots)$ with weights $(\omega_1,\omega_2,\ldots)$, possibly infinite (although this is asking too much without further details), a ...
2answers
1k views

### What are some important uses of random number generation in computational statistics?

How and why are random number generators (RNGs) important in computational statistics? I understand that randomness is important when choosing samples for many statistical tests to avoid bias towards ...
0answers
64 views

### Why matrix inverse is not numerical stable?

I was told by many people, many times, Never explicitly compute matrix inverse, because it is not numerical stable. Instead, use LU, QR, SVD decomposition to solve the linear system. But why? Is ...
4answers
1k views

### What kinds of statistical problems are likely to benefit from quantum computing?

We are at the advent of quantum computing, with quantum languages anticipating hardware quantum computers now available at high and low levels for simulated quantum computers. Quantum computing brings ...
0answers
92 views

### Project Euler Problem 213 (continued…) [duplicate]

This question is a continuation of How should one approch Project Euler problem 213 ("Flea Circus")? I followed the approach of Glen_b outlined in his answer in the page referenced above. I ...
0answers
418 views

### Importance sampling: what is this bias?

I am experiencing what seems to be a bias in importance sampling, which, given that it's an unbiased procedure, should not be there. Consider linear regression $$y = X\beta+\epsilon$$ where there ...
2answers
7k views

### Gradient descent explodes if learning rate is too large

I've implemented my own gradient descent algorithm for an OLS, code below. It work's, however, when the learning rate is too large (i.e. learn_rate >= .3), my approach is unstable. The coefficient's ...