# Tagged Questions

The tag has no usage guidance.

19 views

### How to measure if data conforms to logarithmic curve

I am collecting data that should closely resembles a logarithmic curve. I have many datasets. How can I measure how closely each dataset resembles a logarithmic curve and call out any outlying ...
19 views

### Extracting values from a sigmoidal dose curve

I need to extract the real lethal doses from a sigmoidal dose curve from a probit model. The doses (mg) are the X-Axis and were log transformed. Model parameters were not reported, only that the true ...
14 views

### How to model/predict discrete curve locations from numerical and categorical independent variables

I want to find the principal "parameters" driving the relative location of a set of $K$ discrete curves (observables, dependent variables). The data shape is as follows: ...
120 views

### Average curve from set of curves

I have done some initial analyses on some patient datasets regarding neuro-degenerative diseases. A method I've used is DFA (Detrended Fluctuation Analysis) in MATLAB, which produced a family of ...
80 views

### Why is the “training score” I get from the learning curve of Multinomial Naive Bayes so different from the training score of the Bernoulli version?

I'm comparing the learning curves of Bernoulli and Multinomial Naive Bayes using the 20_newsgroups dataset from scikit-learn for text-classification. I considered both the "training score" and the "...
123 views

### What is a grade-tonnage curve?

What is a grade-tonnage curve ? I cannot find any good online resource, neither wiki, neither any forum... Thanks, PS: sorry if it should be on another website
54 views

### Describe a curve by other than formula, fitting or interpolation

I have a curve defined by a set of $(x,y)$ given points. After ploting these points I get : My aim is to study the sensitivity of the operation that results these points. In order to do that, the ...
30 views

### Name of type of curve that uses x value as a divisor for y

What is (or is there) a name of a curve that is on X and Y axis, where the Y value is divided by X? For example, Y at X being 1 = 100, Y at 2 = 100/2 Y at 3 = 100/3. The type of curve I am thinking ...
2k views

### In statistical terminology, what is the opposite of “peak”?

When we see a curve (or a normal distribution), we describe the highest value as "peak". Let's imagine we have a curve with only a minimum value (like an inverted hat), what do we call that minimum ...
198 views

### Fitting the differences between two curves [closed]

The problem I'm trying to solve is to algorithmically figure out whether two curves converge or diverge in a graph (visually the problem is almost trivial). For examples: The left one is ...
197 views

### find a general formula between two parameters using curve-fit

I am trying to study the relationship between two parameters say A and B for an image. For a single scene S1, I take 20 images ...
50 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 ...
47 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"), ...
213 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 ...
400 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 ...
262 views

### How to determine signficant difference between 2 curves?

I have data on age, gender and weights of children. For example: ...
100 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 ...
71 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 ...
175 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 ...
75 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 ...
298 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()? ...
44 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 ...
3k 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 ...
4k 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 ...
39 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 ...
285 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 ...
95 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 ...
74 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, ...
211 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
51 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 $\varepsilon$ ...
53 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. ...
850 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 \$...
179 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 ...
13k 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 ...
814 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 ...
545 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 ...