The calibration tag has no wiki summary.
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36 views
How can I combine absolute and relative uncertainty components in an uncertainty budget?
I use Excel worksheets to calculate calibration uncertainty budgets as per our implementation of the ISO GUM. Our basic combined standard uncertainty $u_c$ is taken as the RSS of the terms ...
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0answers
39 views
Calibrating speed [closed]
I would like a correct official terminology for calibrating speed.
I work in calibration and we when calibrating our SIS instruments have to calibrate with two measuring sources, i.e.:- for ...
2
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2answers
67 views
Validate a medical test
I've never done something like this before, thus I do not even know where to start with calculating whatever I need.
Following scenario:
We measure a medical value (Glucose) with our device, and ...
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0answers
57 views
Which measure could tell me about what is the best predictor in survival analysis?
I have data of cancer survival, like that:
> my.data
survival stage my_class
27 3 2
221 2 1
43 3 3
...
The survival is the time ...
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0answers
75 views
Multilevel calibration curve in jags
The problem
I am trying to fit a calibration curve from known x and y with jags. I would then like to predict new xes, based on the measurement of new ys. For this, I am following Hamada et al. ...
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130 views
Calibration for random forests
I want to evaluate the calibration of the random forest using val.prob (rms package, R). I have no problems using it and getting an output, but I feel the results may not be accurate because I don't ...
3
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1answer
242 views
How to determine calibration accuracy/uncertainty of a linear regression?
To determine organic carbon concentrations in a water solution from UV spectroscopy I made a calibration curve with known carbon concentrations and measured the UV absorbance. I used R for the data ...
3
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5answers
276 views
Conversion between units of measurement
I have two different measuring instruments, A and B, both measure the same physical quantity but with different unit of measures: $u_A$ and $u_B$.
A is a reference instrument.
I measured a reference ...
3
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1answer
54 views
Confidence interval of multi-step calibration
I need to perform a two-step calibration and I need you to tell me if I am doing that correctly. First I want to calibrate a force sensor with masses. I measure several weights and perform a linear ...
2
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1answer
97 views
Predictive Probabilities
Other than a calibration plot, is there a way to decide how good one models' predictive probabilities as compared to another model.
I'm not interested in error rates as I find them ineffective for ...
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0answers
55 views
Choose among poststratification/calibration weights
I have data from a survey, stratified by country with a roughly equal number of participants in each country. Also, I have calibration totals, three dimensions (say, age, sex and work status) plus the ...
0
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1answer
94 views
Calibrate against multi-dimensional population totals using the survey package?
Is there a way to calibrate against multidimensional control totals using the survey package? I have been able to estimate poststratification weights, but now I'm ...
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0answers
91 views
Curing noncoverage with hot-deck imputation?
Is it advisable to use hot-deck imputation to allow for poststratification in the presence of empty post-strata?
In a survey reweighting exercise, I have population totals for a complete ...
0
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1answer
136 views
Effects of ignoring the sampling strategy
Does the use of calibration/post-stratification imply that the sampling strategy/stratification/individual selection probabilities can be ignored altogether?
In a survey reweighting exercise, I have ...
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0answers
49 views
Choice of calibration totals
If I have fully cross-classified population totals on several attributes, how do I choose which interactions to skip when defining the calibration totals?
In a survey reweighting exercise, I have ...
2
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1answer
89 views
Does good calibration surpass roughly met assumptions and mediocre discrimination?
My question arises from my current task to develop a clinical prediction model using ordinal logistic regression (with rms), but applies to any kind of regression analysis.
The proportional odds ...
5
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2answers
200 views
Visualizing the calibration of predicted probability of a model
Suppose I have a predictive model that produces, for each instance, a probability for each class. Now I recognize that there are many ways to evaluate such a model if I want to use those ...
3
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0answers
46 views
Analyzing categorical data where the last category is unbounded
This is a bit of a long-winded data vis question.
We're gathering data from a water quality test measuring fecal contamination. The test measures fluorescence in 11 discrete chambers. The water is ...
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3answers
173 views
Calibrating a household survey to household-level and person-level control totals
Imagine a (reasonably large) household survey where all persons in every household have been questioned. For the purpose of microsimulation, this survey needs to be expanded to a full population. In a ...
5
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1answer
169 views
Correct way to calibrate means
I'm working on benchmarking the speed of various JavaScript methods.
Part of the benchmark process requires repeating a test for a minimum time (to reduce the percentage uncertainty to at or less than ...
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2answers
2k views
Why use Platt's scaling?
In order to calibrate a confidence level to a probability in supervised learning (say to map the confidence from an SVM or a decision tree using oversampled data) one method is to use Platt's Scaling ...
