Questions tagged [curves]

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calculation of cox-adjusted survival curves

In order to leverage a cox model for calculating adjusted survival curve - one must estimate the baseline hazard function. To my understanding this has to be estimated (non parametrically) for ...
Biased estimator's user avatar
1 vote
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21 views

How to start GNN optimization to get higher precision?

I'm developing a GNN for missing links prediction following this blog post for PyG library. I'm using almost the same GNN with a different dataset. Altough my dataset is similar to the MovieLens ...
James's user avatar
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Can comparison between curves be achieved statistically to group into similar and different sets?

I have a set of aggregate grade data and want to know if it is possible to determine if there are groups of samples of similar grade fraction using R studio. Some of the data: Column A contains ...
Liz L's user avatar
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How best to statistically compare radial intensity curves?

I've the following data. https://drive.google.com/file/d/1_a-mi_Pesx73AnvbKVNr4SzhuujKq9Za/view?usp=sharing These .csvs contain logged radial intensity curves to a distance of 2.2 cm of different ...
Cameron William Michael Murphy's user avatar
1 vote
0 answers
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Phonological errors in children

I have a data (ge3_ratio) with 86 observations measuring the ratio of phonological errors produced by children. The data was collected from spontaneous speech transcripts from 3 children aged 21 to 65 ...
kbg's user avatar
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3 votes
1 answer
645 views

cmprsk cumulative incidence - comparing between two curve with different outomes

I have a question regarding the extracting p-values from the cumulative incidence curves that considered competing risks. I used cmprsk packages and ...
jjjj's user avatar
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1 answer
1k views

Log-rank test for comparing three survival curves?

I have a plot of three survival curves that are stratified by a categorical variable (a=1,2,or 3). The log-rank test can be used to test the global null hypothesis that all these curves are the same, ...
GrantlyBell's user avatar
2 votes
2 answers
63 views

Curve quantification

I have some longitudinal measurement data of 15,000. I smoothed that data with B-spline smoothing and got the following curve. I then want to quantify this curve and extract features for clustering ...
NakataKoo's user avatar
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27 views

Power demand Curves

Which is the correct way to compute the elasticity in this log log regression? Context: When having an log log regresion: log(Y) = log(B0) + B1 log(X), being Y= Demand and X Price, B0 intercept and B1 ...
PeCa's user avatar
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2 answers
706 views

Statistical difference between curves

I have 12 curves (three replicates for each treatment), see attached picture. X=days; Y=percentage. The experiment has 2 variables: A: 4 cases; B: 3 cases. I would like to know, if there is a method ...
dandelion's user avatar
1 vote
1 answer
214 views

Best Loss Function for Shape Resemblance in Time Series

Basically, predicting future values step by step using past values and some covariates as a feature, using some LSTM, Conv layers from tensorflow. I started by using mean absolute percentage error as ...
Della's user avatar
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why does log scale does not start at 0

I need help in understanding the curve shown in the image. As you can see in the image that I-V curves in (a) is for linear scale and it shows 0 Amps at 0 Volts. But for logarithm scale I-V curves in (...
dnalectronics's user avatar
1 vote
2 answers
199 views

Representation of population data mean/median (similar to BMI/age curve)

I want to represent my data (n=150 samples with a curve of value over time, similar to BMI representations in figure). Possibilities are either mean/std and median/percentiles. The question are: Can ...
Jimolrame's user avatar
1 vote
1 answer
2k views

How to fit the flipped exponential-function in Excel? [closed]

I would like to know whether it is possible to fit the second graph below in Excel with an exponential fit? Unfortunately the "Exponential fit"-button is greyed out and I can't choose this ...
NirvanicUniverse's user avatar
2 votes
0 answers
185 views

Intuition behind Cumulative Accuracy Profile(CAP)

I am really having trouble understanding the intuition behind Cumulative Accuracy Profile(CAP) Curve. I mean where exactly does the CAP curve is used and how do you read the CAP curve? Parts of the ...
Thalassophile's user avatar
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modeling a electrical pulse which is technically time dependent

I have an electrical pulse that I need to fit a curve to a certain area of but not the entire thing. The whole pulse looks like this However the only part that I need to model is this My boss ...
alittleloopy's user avatar
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913 views

Adjusted Kaplan Meier in STATA : stcurve or sts graph adjustfor

I've been asked by a reviewer to plot an adjusted Kaplan Meier graph. I understood that with sts graph and adjustfor, the adjustment was to zero values of all the variables. So I tried to use stcurve,...
Javier Rodriguez's user avatar
1 vote
0 answers
582 views

KS-style test between curves in general

The setup of my problem is that I have some response variable, $Y$, and a predictor, $X$. I have measurements on both variables from two groups. In each group, there is one $Y$ per $X$. I want to ...
Dave's user avatar
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3 votes
1 answer
181 views

Standardize by min, max, and arbitrary chosen middle to range from -1 through 0 in the middle to +1 in max

How to standardize data by the following example: ...
Przemyslaw Remin's user avatar
1 vote
0 answers
70 views

Difference/comparison of two different sized sets of data

I have the data of two different devices (a and b) measuring the same outcome along the time. These results are approximate but have different values. I would like to assess the variation/agreement ...
Mafalda Couto's user avatar
-1 votes
2 answers
556 views

In elbow curve how to find the point from where the curve starts to rise? [closed]

I am computing a distance on my data. The result is then being sorted in ascending order. The samples having distance more than a specific threshold are to be marked as outliers and will be discarded. ...
Faiz Kidwai's user avatar
1 vote
1 answer
304 views

Should Learning Curves be Plotted only on Train or the Entire Dataset?

In order to compare a few models to start my ML project, first I split the dataset into train and test, and then performed nested CV on the training set only and got my fair estimate of true risk on ...
Odisseo's user avatar
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0 answers
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What defines a plateau in a saturation curve?

I am working on a dynamic visual. To be more specific, it is a saturation curve (also known as accumulative/cumulative curve that reaches to a maximum of 100%. I am trying to define a variable that ...
Learner123's user avatar
1 vote
1 answer
95 views

What method can I use to produce a single curve from a number of curves?

I am looking for a good method to combine a set of curves into a single curve. Those curves have been produced by performing a measurement/testing n-number of times under similar conditions. What I ...
Midas's user avatar
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2 votes
0 answers
241 views

how to calculate curvature of multivariate function?

EDIT1: tried to clarify the question Context In the context of an MCMC investigation of non-linear interaction effects in dichotomous models, I am creating data generating processes based on the ...
Elad663's user avatar
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How to represent local significant differences between curves

I want to compare some curves to a 'normality corridor', and I would like to show in what regions (x values) the difference is significant.Take the example below, where I want to compare the dashed ...
Zep's user avatar
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-1 votes
1 answer
133 views

How to compare curves behavior?

I want to know how I can compare the "behavior of curves" and see what curves behave more similar. In the link below, in the 1st graph we have 4 curves through out time. http://www.sooty.ca/sooty/BDI....
Sebastián Viniczay's user avatar
0 votes
1 answer
2k views

ROC curve:difference between FPR x TPR and false positives x true positives

Background I'm trying to understand ROC curves, however I sometimes read that you can simply go one up for a True positive (TP) and one to the right for a False positive (FP), as mentioned here: ...
KingBoomie's user avatar
4 votes
1 answer
1k views

ROC curve: small focused sample vs large sample

Background I'm currently reading the book Data ming: practical machine learning tools and techniques and came across the following ROC curve: The text corresponding to this figure: Method A ...
KingBoomie's user avatar
2 votes
1 answer
628 views

Choosing estimator based on Precision-Recall Curve

I hope you will help with this one. Below you see my Precision-Recall curves after performing 10-fold Stratified Cross Validation on my dataset. Note that my dataset is imbalanced that's why I'm ...
christinabo's user avatar
1 vote
1 answer
1k views

"Changing" standard deviation?

I will admit to being just a hair about a novice when it comes to stats, but I feel like I have a decent working knowledge of things such as normal distribution, linear curves, standard deviations, ...
The Average Joe's user avatar
4 votes
1 answer
1k views

How can Precision-Recall (PR) curves be used to judge overall classifier performance when Precision and Recall are class based metrics?

How can Precision-Recall (PR) curves be used to judge overall classifier performance when Precision and Recall are class based metrics? Since in a binary classifier, there are two classes, often ...
Aalawlx's user avatar
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0 votes
1 answer
269 views

Logistic-regression probability score used for reordering rows for plotting ROC curve: is it the actual, positive, or negative class probability?

I want to draw my own ROC curve, such as explained in the accepted answer to this question: Understanding ROC curve However, it isn't clearly explained what the 'score' used represents. It is used ...
Aalawlx's user avatar
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1 vote
1 answer
2k views

ROC AUC and PR AUC: Are the AUC values different for each class?

When dealing with a binary classification problem, where the decision function threshold is being varied from 0 to 1 at step 0.1: When calculating the Area Under the Curve (AUC) for a ROC Curve plot (...
Aalawlx's user avatar
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0 votes
1 answer
128 views

Normal distribution curve percentages

Lets assume I’m grading following a normal distribution but instead of having a standard grading scale from A to F I have a grading scale from A to J with no plus or minus. Whats the percentage for ...
Nasser's user avatar
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1 vote
1 answer
211 views

Vertically translated depreciation curve: Update the exponential regression coefficient

I have an exponential regression equation that I use to predict the condition of roads. The equation can be found on page 53 of the original master's thesis: Development of a Flexible Framework for ...
User1974's user avatar
1 vote
1 answer
2k views

How to extend the dynamic time warping to 3D Cartesian space

I already searched the topics here but couldn't figure out clearly what to do so I'm asking here. I have thousands of fiber tracts (the outputs of a tractography algorithm on brain diffusion MRI) that ...
TDK's user avatar
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0 votes
2 answers
3k views

Exponential regression trendline does not match data

I'm attempting to generate an exponential regression equation using Excel 2010. I plan to use the equation to predict the future condition of roads. I've mocked up a simple chart in Excel using the ...
User1974's user avatar
3 votes
1 answer
403 views

Clustering curves [closed]

I am trying to cluster gas wells based on their production behavior based on Gas/Water ratio vs cumulative water produced plots. Would appreciate suggestions to solve this problem.
Anoop Kumar Mangaraj's user avatar
1 vote
1 answer
135 views

Road condition: Project future condition by appending part of a deterioration curve?

I inspect a road network's condition every three years: ...
User1974's user avatar
1 vote
0 answers
31 views

Constant Curve for Cumulative Binomial

I am simulating traffic flow and have come across a rather interesting statistics problem that I'm having trouble wrapping my head around. I am modeling a stretch of road comprised of 2 lanes. Lets ...
Acumen Simulator's user avatar
1 vote
1 answer
224 views

Curve disaggregation with neural network

I have to extract a specific curve from an aggregate curve. An example is illustrated in the picture below, the blue curve is the aggregate curve, and I want to extract the red curve from the latter. ...
Nicola's user avatar
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1 vote
0 answers
192 views

Statistical test to use to compare EMG waveforms with only the mean and sd?

I have to compare processed EMG waveforms (smooth curves) that I recorded from 7 different leg muscles of 4 different subjects to reference EMG data (Winter book). The problem is that for the ...
Menor's user avatar
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3 votes
0 answers
264 views

Comparing two (or more) curves

I'm rather new to R and statistics. I'm analyzing intonation curves (time, fundamental frequency), and I'm interested in comparing pitch curves of different speakers. I am particularly interested in ...
LeonardoC's user avatar
5 votes
1 answer
732 views

Getting ROC curve from markov chain in r

I've been working on some attribution modeling in R, following the markov chain-based methodology described here. In order to compare the sensitivity and specificity trade-offs of using models of ...
babyseal's user avatar
8 votes
2 answers
4k views

The issue of quantile curves crossing each other

While trying to perform some quantile regressions on some data I have encountered a classic problem: the 0.25,0.50, 0.75, 0.95 quantile curves are crossing each other (I am dealing with linear curves)....
Statlearner's user avatar
1 vote
0 answers
132 views

Measuring magnitude of variation between 2 one-phase association exponential curves

I am currently testing the independence of two unpaired conditions A and B; with each condition representing a set of 12 values (aka bins) that compose a one-phase association exponential curve. Each ...
user3242289's user avatar
7 votes
1 answer
142 views

Does it take progressively fewer EXTRA correct answers to move up a grading curve in standardised exams?

A previous year's grading curve for an exam I will be sitting is : Assuming the exam has 100 (or any number of) questions each equally weighted, will it take fewer extra correct answers to move up ...
K-Feldspar's user avatar
0 votes
1 answer
2k 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 ...
kinger9120's user avatar
0 votes
1 answer
40 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 ...
user1211346's user avatar