# Questions tagged [error]

The error of an estimate or prediction is its deviation from the true value, which may be unobservable (e.g., regression parameters), or observable (e.g., future realizations). Use the [error-message] tag to ask about software errors.

816 questions
Filter by
Sorted by
Tagged with
8 views

### Systematic Error Propagation with a Linear Fit

I am doing a Physics experiment in Atomic Spectroscopy. I am trying to find the wavelengths of certain spectral lines. The wavelength readout on our monochromator is not correct, so we must calibrate ...
53 views

### Assumption that $E(u) = 0$

I have been thinking about this question for a while: We assume that $E[u_i] = 0$. What are the implications for the OLS estimator if this assumption is not valid? Explain why this may or not be the ...
37 views

### How to interpret expectation of one specific observation of $u_i$, eg. $E[u_1|X]$?

I'm a bit hung up on how to interpret the expectation of a single observation of the error term... especially in the context of the zero-conditional mean assumption. If the true population model is ...
21 views

27 views

### How to fix 'Error() model is singular' when running a mixed ANOVA in R

This is my data set I am trying to run a mixed ANOVA on in R. Subject Substrate Biomass Pb ...
36 views

### MAPE and SMAPE shift invariance (bias)

MAPE (Mean Absolute Percentage Error) and SMAPE (Symmetric Mean Absolute Percentage Error) both are sensitive when the TRUE ...
23 views

### Bounded loss function whose minimizer is the mean

Let $$y = \operatorname*{argmin}_\hat{x} \operatorname*{E}_x L(|\hat{x} - x|)$$ where $L$ is a loss function. As noted here, if $f(s) = s^p$ then $p \rightarrow 0$ implies $y \rightarrow$ the ...
12 views

### Mean Percentage Error on k-fold CV vs. Training Set

I'm performing a regression using a Gradient Boosting Machine. When comparing the cross-validation predictions with the true values, the Mean Percentage Error is around -6%. However, using the model ...
30 views

### Weighting the data for a fit

I have 5 data points with errors associated to them $y_i\pm dy_i$ and the corresponding $x_i$ values (which don't have uncertainties associated to them). I need to calculate the difference between the ...
4 views

### How to extract systematic errors from data

I am a bit confused about estimating the systematic error (I think it is systematic) from an experiment. Here is a (simplified) description of it. Assume that 2 groups measure the length of a cube ...
43 views

### Different reconstruction errors using different PCA algorithms

In Matlab, I perform PCA on a centered and scaled (std-scaled) data set X_cs in four ways: builtin pca using the builtin ...
111 views

### What is the relationship between estimation error, approximation error, bias, variance in machine learning?

I'm a beginner in machine learning. I was reading http://ciml.info/ 5.9 Bias/Variance Trade-off According to this book: The trade-off between estimation error and approximation error is often called ...
65 views

### AutoEncoder Reconstruction error for Anomaly Detection

I'm building a convolutional autoencoder as a means of Anomaly Detection for semiconductor machine sensor data - so every wafer processed is treated like an image (rows are time series values, columns ...
29 views

### Bayes classifier and unavoidable error

Consider the following two-class classi cation problem, where $Y = 0 \text{ or } 1$. Suppose $Y$ is a random variable satisfying$P(Y = 0) = \frac{1}{3}$ and $P(Y = 1) = \frac{2}{3}$: Moreover, we ...
30 views

### Specification on power spectral density for population data

What is the best way to put a specification on the single-side auto-power spectral density (PSD)? We have a product for which we have a time signal. For this signal we calculate the PSD (or ...
20 views

### How is the total error equation derived?

In this video Ng said that there is a Bayes optimal error(also called irreducible error), and in this article I learned that the total error is equal to the squared bias plus the variance plus the ...
3 views

### Error Analysis For Denoising?

I have a collection of noisy audio files and their corresponding "clean" versions. I used some statistical methods like low-pass and high-pass filtering to try and remove the noise in these noisy ...
71 views

### WMAPE / WAPE for the evaluation of time series with positive and negative values

I have a time series y that has both positive and negative that I want to predict. For the prediction I normalize the values to a range between 0 and 1. If I give ...
20 views

### How do you interpret regression including log(GDP)?

I have the regression equation: Growth = B0 + B1 * log(GDP) I'm trying to understand how I would interpret this. Let's say B1 = 0.05 (se: 0.001). Would this be ...
37 views

### What is a Good Error Target

I am modeling a forecast for product categories using auto Arima in R. I'm getting MAPE of between 9-15% on average. We don't have any historical records of forecasts vs actual so I don't know how ...
11 views

### Error weighting in two point regression analysis [closed]

I have following problem: I do measurements of the formation of a product at two time points (t=0 and t=15), each in triplicates. Afterwards I calculate the mean value + the standart deviation of ...
23 views

13 views

### Quantifying error with paired measurements from multiple conditions

I have a set paired measurements (continuous values) obtained using different sample types and different methods. I.e., for each subject, I have measurements for samples A and B each on device 1 and 2 ...
15 views

### Within-subjects aov() output error term interpretation

What does it mean when the main effect of an independent variable appears twice in the output (once under Error:Pno, and once under Error: Within)? My data set (mydata) looks like this: 4 columns (...
36 views

### RMSE with and without standardizing the output variable

I have a time series data that I would like to be able to forecast. I was trying to standardize the data as my columns are all of different ranges. I have standardized the input variables, but was ...
17 views

### Errors on the mean

I have some data points from a measurement of a given quantity, and each point has an error associated to it. I want to report as the final value the mean of the measurements, but I am not sure what ...
31 views

### What is default error threshold Tensorflow? [closed]

My homework states that I am asked "to report the default error threshold used in the TensorFlow default configuration for convergence. Usually it is documented for MNIST and CIFAR-10". What's that? ...
38 views

### Dividing the MAE by the average of the values

I would like to parse the MAE (Mean Absolute Error) to a percentage value. I know there is the MAPE (Mean Absolute Percentage Error), however it has some drawbacks as going to infinity if one of my ...
29 views

### How to determine whether a validation study produces acceptable results?

I have a method developed to predict results of a signal that outputs an root mean squared error (RMSE) for each subject. Combining all 40 subjects (2 samples for each subject), I get a mean RMSE of 5....
31 views

### Fitting data with unknown noise with complicated model — can anything be done?

I have some experimental data, where due to the nature of the experiment (which I am not familiar with) the errors are not known. The data follow a rough non-linear trend but clearly are noisy as for ...
50 views

### How do I correctly estimate the size of a subpopulation using noisy observations?

To preface this question: please comment on whether my description of the problem is missing details or the problem itself is not well-posed as I'm seeing a lot of views but no activity. I am trying ...
19 views

### Comparing predictability of outcomes across leagues

From time to time I encounter newspaper articles with titles like “Unpredictable English Premier League Keeps Us Guessing”, which make claims about the difference in predictability of outcomes across ...