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4
votes
1answer
49 views

How do I detect the “corner” in a set of data as it arrives?

Apologies from the start if my terminology is inaccurate, but what I have is a series of measurements that are made over a short time period from a hardware device to which I have just supplied a ...
0
votes
1answer
25 views

Comparison method for curves using percentiles

I have a question regarding the use of quantiles for determining the enveloppe of a curve. This is what I am doing: I have a continuous variable ("var") that I turned discrete using cut ("var_cut"), ...
0
votes
0answers
45 views

Statistical comparison between two curves

I have two time course experiments of the same study, and I want to determine if the time course curve is statistically significant or not. Let's say I treated a group of people with drug A, measure ...
1
vote
1answer
127 views

Curvilinear relationship with moderator

I am trying to moderate a curve and determine which equation I should follow. A simple curvilinear relationship has the following equation: (1) $Y = b_0 + b_1X + b_2X^2$ (i.e. a linear term and a ...
0
votes
1answer
156 views

How to determine signficant difference between 2 curves?

I have data on age, gender and weights of children. For example: ...
0
votes
0answers
25 views

Comparing Learning Rates using Unit Curve in R

I have data for an experiment where 2 groups (Role) were tested over 3 consecutive trials for a task and time to complete task was recorded in sec. I wanted to compare the learning curves of the two ...
1
vote
0answers
28 views

Comparing two curves with peaks

I have a question about analysis method and I would be very grateful for the help! So, I have two groups: Active and Placebo, each group is measured for 20 different concentrations (from 1 to 20) 6 ...
0
votes
1answer
54 views

Average multiple precision recall curves

I have a binary classifier that I evaluate using cross validation. The classifier gives me a score for each observation and for each of the test sets I use a varying threshold to compute precision and ...
1
vote
0answers
34 views

Types of growth curves that can be compared using statmod compareGrowthCurves

I'm using the function compareGrowthCurves in the R package statmod, but I can't seem to find an explanation of what types of curve this is valid for. Does anyone ...
1
vote
0answers
165 views

Integrate first derivation - area under curve of first derivation

I want to calculate the area under the first derivate. Can I do that with splinefun()? ...
2
votes
1answer
37 views

Gaussian Process for Closed Curves

A Gaussian process gives a probability distribution over functions that pass through the data points. Is there a way to parameterize the Gaussian process to give a probability distribution over closed ...
4
votes
1answer
981 views

How to form a Precision-Recall curve when I only have one value for P-R?

I have a data mining assignment where I make a content-based image retrieval system. I have 20 images of 5 animals. So in total 100 images. My system returns the 10 most relevant images to an input ...
2
votes
0answers
1k views

Test for statistical difference between two curves on same plot?

I've got data plotted for A/Ci curves (plant physiology, A=photosynthesis rate, Ci=internal CO2 concentration--essentially it's a dose-response relationship). Generally, when this type of data is ...
1
vote
0answers
33 views

Line smoothness/waviness

I am working on a project which requires me to watch video of athletes and measure the straightness/smoothness/waviness, whatever term is acceptable, of their spine. Dividing the spine into segments ...
2
votes
0answers
191 views

Comparing facial curvature of two human faces

I need help determining if what I'm doing is sufficient. I have extracted the "curvature" from two human faces (essentially the curve that goes from one ear, down the face to the chin, and back up to ...
2
votes
2answers
84 views

Estimation and comparison of flowering curves

I am a research scholar and monitoring phenological events of timber line at Himalayan region from past 4 years. During data analysis I found a research paper Estimation and comparison of flowering ...
0
votes
0answers
66 views

Frechet Mean of Multiple Curves

I'm working on determining the Frechet mean of several curves. I am using this equation: $$ \sum_{n=1} (P_a - P_b)^2 $$ but I'm not entirely sure how I would do this across multiple curves. Also, ...
-2
votes
1answer
127 views

Unsupervised classification of curves (in R)

I'd like to know if there is a method (in R) to classify curves based mainly on their appearance ie one cluster will represent a specific form of curves. Thanks
1
vote
0answers
39 views

Hilbert curves: bounds / probabilities of preserving neighbors

Hilbert Curves (Wikipedia) are space-filling curves said to "fairly well preserve locality". Do you know any theoretical results here, such as bounds that neighbors within a radius of $\varepsilon$ ...
0
votes
0answers
43 views

Matching curves

I've a large number of curves over a finite interval. Given a new curve C, I want to find a set of curves in the database s.t the area between a matched curve and C is less than a certain threshold. ...
14
votes
2answers
644 views

Checking for a statistically significant peak

I have a set of data, $y$ and $x$. I would like to test the following hypothesis: There is a peak in $y$; that is as $x$ increases, $y$ first increases and then decreases. My first idea was fitting ...
2
votes
3answers
155 views

Are there methods for automatically detecting features of a curve?

I have a raw discrete data(curves). I need to find methods for detecting features of each curve. Some example features: 1) Stable growing 2) Fast growing 3) Stable falling 4) Fast falling 5) And so ...
9
votes
5answers
7k views

Similarity measures between curves?

I would like to compute the measure of similarity between two ordered sets of points---the ones under User compared with the ones under Teacher: The points are curves in 3D space, but I was ...
5
votes
1answer
467 views

Shape detection for time series data

I have a large collection of time series - measurements taken every 15 minutes (96 measurements in a day) over the span of 1 year at various different locations. I've broken up each time series into ...
2
votes
2answers
309 views

Convex vs. concave curve - measurement or index

I am interested in a measurement or index that will tell me if a curve is more convex or concave versus a straight line. This curve is sampled in n points and I know the x and y coordinates of these ...
0
votes
1answer
1k views

Tutorials for drawing an ROC curve

Are there tutorials you recommend that teach how to draw an ROC curve? Thanks.
5
votes
2answers
2k views

Fit between two curves

I am trying to determine the fit between two curves (example shown below). Both curves are plotted here as a bunch of XY data points (not functions). The curves represent the trajectories of two ...