Questions tagged [data-analysis]

Use for question relating the the techniques of data analysis.

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18 views

What is the difference between horizontal units and horizontal scale at an oscilloscope?

This is a picture of the data of a given measurement by an oscilloscope. I would like to know what the difference between horizontal units and horizontal scale at an oscilloscope is. I would be so so ...
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1answer
44 views

Why do I have to draw a big triangle to determine the gradient of a straight line using the slope triangle method?

I'm an igsce student, I'm taking igsce OL phyiscs. It's stated in my book that after I draw a graph and the line of best fit, I should get the gradient by choosing two points then form a right angel ...
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18 views

Magnetic flux as a function of distance experiment

For my electrical engineering senior design I created an experiment to test magnetic flux (more voltage) increase from a material in a coil of wire. There is a large sending coil with A.C. voltage and ...
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2answers
45 views

Does it make sense to average data taken continuously as the system evolved?

I have a simulation where a bunch of particles are moving. Every time step I fit a gaussian (through non-linear least squares) to the distribution of speeds. Here I end up with a temperature $T_i$ and ...
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35 views

What is the relation between statistical and instrumental uncertainty?

I've been studying some error analysis on An Introduction to Error Analysis: The Study of Uncertainties in Physical Measurements by John R. Taylor for an introductory course. At the beginning of ...
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Q. Significant figures on graphs

When displaying experimental data on a graph, must both axes use the same number of significant figures, which would be the variable with the smallest number of significant figures? Or (because a ...
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31 views

X-Ray Diffraction pattern peak tailing

I have recently been working with Rietiveld refinement on powder X-Ray Diffraction (XRD) patterns by using the GSAS2 (General Structure Analysis System) program where, one of the steps, is to produce ...
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3answers
69 views

Calculating the distance between a nuclear bomb and an object hit by the shockwave, all the while taking the video frame rate into account? [closed]

Imagine you are watching a YouTube video where a nuclear bomb goes off. Exactly six seconds later, the shockwave arrives and hits an object that is some distance away. How would you go about ...
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22 views

Prevent biased data analysis

When analysing experimental data it is simple to fool oneself. Therefore, I am interested in methods to prevent myself to draw biased conclusions. Robert MacCoun and Saul Perlmutter: "Blind ...
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1answer
45 views

What’s the difference between ‘decimated‘ and ‘undecimated’ data?

How is ‘decimated’ data different from ‘undecimated’ data?
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1answer
29 views

Linear fit error for beta decay spectrum

I'm trying to get an upper bound to the neutrino mass with kurie plot. In order to do that I need to make a linear fit in order to get energy value that corresponds to $y=0$. ($y$ the kurie plot). The ...
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What is significant in broad and narrow resonance peak to internal structure of the resonance?

I read about the multiquark system and It seems like many people said that a narrow peak mostly likely to be a molecule structure. The broad peak seems to be a compact structure. This is like a kind ...
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27 views

Generating Positive Kinetic Energy (PKE) from car velocity [closed]

PKE have high importance on fuel consummation and Eco-driving. I have a data frame with 3 columns, Time (each second), Speed(KM/H) in each second, and RPM ,from this data frame I want to calculate ...
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42 views

Understanding the ordinate at $R=0$ in a capacitor experiment [closed]

I've done an experiment to study a capacitor's discharge time and calculate an unknown capacitor's capacitance. With the help of an oscilloscope, I measured the time it took for the capacitor's ...
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41 views

I don't understand how to interpret “Events/MeV” in plots like this

I was reading a paper regarding electron excess events in MiniBooNE data and I came across the following plot: I don't understand how to interpret the meaning of "events/MeV". This is a histogram and ...
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Modelling a spring powered car - using a cubic

I've designed, built and tested a mousetrap-powered car. However, I'm having trouble with how to fit the results. I claim an approximate fit to a displacement-time graph of the car should be a cubic ...
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251 views

How to incorporate the uncertainty of the model coefficients in the prediction interval of a multiple linear regression

I'm dealing with the modeling of small experimental physics data sets (specifically the stickiness of glue-compounds). As most experimental work does not generate thousands of samples, but rather a ...
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1answer
36 views

Optimizing Muon Lifetime Data

I performed an experiment which measured the lifetime of a muon. The apparatus was very archaic and susceptible to disturbances, which means that there would inevitably be some unreasonable data ...
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1answer
38 views

Power Spectrum Density of real valued time series data

There are real valued time-series data X(t) and corresponding auto-correlation function ACF(t)=$\left<X(0)X(t)\right>$. As written in wikipedia, Power Spectrum Density (PSD) can be calculated ...
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Optical pyrometry data analysis and manipulation

Today I was doing my Optical pyrometry lab experiment with a following setup. I had a wolfram wire light bulb connected to a circuit in which I could control voltage. Using the pyrometer, I was to ...
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1answer
44 views

Homework/Lab question about my data analysis

I in the experiment, I have tried to find a relationship between a quantity B and quantity I. First I plotted the raw data into a graph and tried different curve fits in excel. This is the graph that ...
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159 views

Graph analysis of accelerometer data

I used my mobile accelerometer sensor to collect data from a moving bike where I held it in my hand in a way that the smartphone sensor +Y axis is in the direction of the moving bike always. This can ...
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1answer
31 views

Can we plot a FFT for a Decibel vs Seconds data?

I was plotting FFT for Decibel values corresponding to the time in which it was recorded using a DAQ for My project, The sample data looks like this, I was attempting to plot the FFT thinking that ...
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1answer
343 views

Light Bulb Resistance

If the voltage and current of a circuit containing a light bulb are measured using a multimeter after consecutively lowering the voltage (building of a data set), what (type of) function will describe ...
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36 views

How long should I record the data of walking acceleration for FFT analysis?

Seems there is no apparent frequency of walking activity (it should be approximately close to 2 Hz) Is it because the time of the data is too short? Here is my csv file:enter link description here
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1answer
50 views

How to subtract background from many spectra which were taken with different background intensity?

I have two spectra, a spectrum of background signal (let's call it Reference) and measured spectrum consisting of searched signal and background signal. The searched signal is a peak/s with various ...
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47 views

Calculating uncertainty in a fitted model

I am working on a project that requires the measurement of the Verdet constant of a material by observing a phase shift in the cosine squared model provided by Malus's law. I have recorded the ...
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1answer
57 views

How to combine several dependent predictions and get the best estimate?

I want to predict the value of some physical quantity $P$ at a time $t$ using actual measurements of $P$ acquired before and after $t$. The formula I use for making these predictions is: $$\hat{P}_{t}...
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Question about FFT analysis of a signal

In labs we had to measure the oscillations of a pendulum using an electric sensor. So basically, my data consists of time and voltage (which represents amplitude) pairs. The task was then to perform ...
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5answers
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How exactly do you avoid fooling yourself?

In cargo cult science Feynman writes: "Millikan measured the charge on an electron by an experiment with falling oil drops, and got an answer which we now know not to be quite right. It's a ...
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60 views

Linear Regressions vs Algebra & Averaging in Solving for a Constant

I'm current taking AP Physics, and in both of the labs performed so far (Snell's Law/Refraction and Galileo's Inclined Plane), I have been trying to calculate some constant from a linear relationship ...
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33 views

Step-like contribution to background $\gamma$ ray peaks

I'm reading the paper "Analytical functions for fitting peaks from Ge semiconductor detectors" by R.G. Helmer and M.A. Lee. For $\gamma$ ray peaks the spectral "background" in the region of a peak: ...
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27 views

What physical interpretation can we derive from this experimental step up?

(This is not a homework question!) An experimental set up shows 2 rigidly placed stands, with pieces of metal links joining with each other forming a chain. The chain is hung from the top point to ...
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64 views

Is there an index of common spectral lineshapes or table of common lineshape functions?

Is there an index of common spectral lineshapes in physics? Is there a program that automatically tries fitting to many different lineshapes? By line shape I mean the function that, given ...
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137 views

What should be the real error band of a fit function?

This is a question concerning data analysis. It could relate to particle/nuclear physics or other field. Please note that this question has nothing to do with technical problems, and is more of a ...
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3answers
318 views

How to Interpolate When Reading a Scale

Suppose, I am taking measurement with a scale whose least deviation is 1mm. the length of something seems to lie between 44mm to 45mm. But my instinct says, it's 44.7mm. So, the question is I should ...
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5answers
721 views

Calculating mean velocity: using time or velocity? [closed]

Background I have been running tests which involve timing an object moving a certain (fixed) distance, $s$. Each test has been repeated 3 times, and the 3 times ($t{_{1}}, t{_{2}}, t{_{3}}$) for the ...
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1answer
95 views

Fitting power law with shift to experimental data

I have some data that I can tell visually that scales like a power law. However, the $x\rightarrow \infty$ and $y\rightarrow \infty$ asymptotes of the data are nonzero. I should thus fit the data to ...
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21 views

Data Adaptive technique

I read in many research paper about the data adaptive analysis techniques. I tried a lot to find the meaning of 'adaptive' in data analysis. What is the main function of the adaptive nature of the ...
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1answer
126 views

Entropy and data redundancy

I have a quick question about the redundancy of data and the information that it represents. A means of evaluating the amount of information contained in the data is the notion of entropy. 1) For ...
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2answers
127 views

Least-square fitting to data (sine function): what is the error of the derived fit parameters?

I have a set of data. I want to fit it to a sine function of the form : \begin{equation} f(x)=A sin(\omega x+B)+C \end{equation} I use the least-square method to find the appropriate fit-parameters ...
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2answers
98 views

What software programs are recommended for background extraction and peak fitting?

I have an energy spectrum for various gamma sources. What software programs are recommended for background extraction and peak fitting in this case?
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22 views

What Dimensionality Reduction method I can follow on a dataset that has Physics Parameter?

I am trying to model data related to Locomotive Train. We have a various set of parameters and we have the possibility to generate a few more parameters from this. Our model is currently using a lot ...
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1answer
38 views

Power law correlation between with three parameters

I made a CFD model of the Centrifugal Atomization Process. Studies show that the mean particle size $d_{32}$ can be expressed as a function of the three operating dimensionless numbers (Reynolds, ...
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1answer
39 views

Normalize accelerometer data based on non-central location

I am trying to "normalize" accelerometer data for a sensor that is not centered on a car. In the image below, you can see how centripetal force changes based on location. In my case, I only have one ...
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1answer
314 views

What is the meaning of true value and uncertainty from a measurement?

I am taking the following example: Lengths of an object are measured as : 5cm , 5.2cm , 5.1cm , 5.5 cm. Calculate the true value and the error . The answer is True value = 5.2 cm error = 0.15 ...
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2answers
137 views

Why is the resolution or measurement uncertainty of $G$ so bad?

I sorta know how the Cavendish apparatus works, and I know that "Gravity is an extremely weak force" for subatomic particles in comparison with the E&M or nuclear forces that act on these ...
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Uncertanty in Chi-squared measurements, spectra-like

Let's say I have some observational data. For example: in a certain wavelength interval I measure the flux, 10 000 points, and I have the uncertainty for each one of them. For example: ...
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4answers
2k views

How do I fit a resonance curve?

In an experiment, I collected data points $ (ω,υ(ω))$ that are modeled by the equation: $$ υ(ω)=\frac{ωC}{\sqrt{(ω^2-ω_0^2)^2+γ^2ω^2}} \,.$$ How can do I fit the data to the above correlation? And ...
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How do we know the LHC results are robust?

Nature article on reproducibility in science. According to that article, a (surprisingly) large number of experiments aren't reproducible, or at least there have been failed attempted reproductions. ...

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