Questions tagged [data-analysis]
Data Analysis is the process of evaluating data using analytical and logical reasoning to examine each component of the data provided.
15
questions with no upvoted or accepted answers
3
votes
1answer
181 views
similarity/distance measurement between two ranked sequence
Is there an efficient way to measure similarity/distance between two sequences of ranked numbers/letters. The two sequences are of different length, and only have some elements in common?
For example,...
3
votes
0answers
117 views
Spatio-temopral wavelet analysis
Am quite new to wavelet analysis and would like some help. I am performing a spatio-temporal analysis of monthly gridded rainfall data. With PCA, I can reduce the dimension of the rainfall data into a ...
2
votes
1answer
123 views
How to extract connected components from persistence diagram?
From the given point cloud (Fig. 1), I use Scipy-TDA to extract persistence diagram (Fig. 2). What I'm interested in is to extract 3 circles. For example, I'd like to know 3 center points and labels ...
2
votes
0answers
31 views
Identifying the time window at which a meteorological factor influences tree growth the most
This is a problem I am encountering in a research project. I have thought of a naive approach to solve it which relies on many assumptions, is not guaranteed to work, and would be tedious and ...
2
votes
0answers
58 views
Error in treating non-uniformly spaced data as uniform
In discussing smoothing filters,
Numerical Recipes p. 772 says
... irregularly sampled data, where the values $f_i$ are not uniformly spaced ...
one can simply pretend that the data points are ...
2
votes
0answers
1k views
Can post-processing use topoSet and createPatch without screwing up the results?
I would like to use patchAverage to obtain the average pressure on an object that consists of multiple patches (due to different boundary conditions), however ...
1
vote
0answers
85 views
Eigenfaces Algorithm
This might be a silly quesntion but recently I've been trying to program the eigenface algorithm using PCA, so I arranged the face vectors vertically in a matrix X such as: X = [x1,x2,x3,...,xn];
In ...
1
vote
0answers
25 views
Validating a Markov chain and Bagging to find overall model
let´s say I estimated a Markov chain by splitting my data into traning and test data, and estimating the transition matrix for the traning data yields
$$ P=
\begin{bmatrix}
p11 & p12 &...
1
vote
0answers
31 views
Use custom defined metric(not matrix) in Javaplex
I'm about to get started trying to use Javaplex for the first time for some application in topological data analysis (TDA) and I want to use a custom defined metric. From looking over the documents, I ...
1
vote
0answers
42 views
Spectra of the energy flux VS transfer spectra?
In direct numerical simulation of turbulence what is the advantage to look at the spectra of the energy flux rather than the transfer spectra?
The transfer spectra corresponds to the triple-velocity ...
0
votes
0answers
21 views
I need help developing a process to map many individual records (from a database) into larger groups
There are many rows of data in a database table, each of which contains many columns.
ID (numeric - 12345, 12378, etc)
Name 1 - AAA,BBB,CCC
Name 2 - dd, ee, ff
Name 3 - Ggg, Hhh, Iii
The objective ...
0
votes
0answers
46 views
Triplet optimization algorithm producing weird results?
I wrote an algorithm for data analysis using the CERN ROOT framework. It takes in three files of sorted UNIX timestamps from a single year and pairs them up in the closest triplets, where each file ...
0
votes
1answer
74 views
How to improve the efficiency of periodicity detection for long time based lined and gapped datasets
Our data set has $10^4$ data points, but has a long baseline and many gaps. As the histogram shows, the horizontal-axis is time and most of the time, there are no data. The vertical-axis is data ...
-1
votes
1answer
27 views
Parameter explained by many distributions
If we had, for example, labeled data, where for each entry (label) we have several data distributions associated to it, how can I get something meaningful from them?
Is this a solvable problem? Is ...
-1
votes
1answer
38 views
Trouble Estimating Motor Parameters with Least Squares in MATLAB
Basically, I'm trying to use Least-Squares to estimate the parameters of a DC motor.
My system can be modeled by the following matrix equation:
$$\begin{bmatrix}V_{input}(t)\\0\end{bmatrix}=\begin{...
