Questions tagged [data-analysis]

Use for question relating the the techniques of data analysis.

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141 views

How to find exponential values

I have a power equation for flow between two circular disks on a common axis as stator and rotor, which follows, $$P = \frac{n^a}{G}\tag{1}$$ Where: $P$ = power, $n$ = revolution (1200 rev/min), $...
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2answers
86 views

Consistency of data

In particle physics, what factors do we consider to conclude that the measurements done by two different experiments are consistent with each other? (You may even explain the concept with an example)
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1answer
42 views

Tracking efficiency for experiments at CERN

For various experiments (e.g. ALICE, CMS etc) at the CERN-LHC, people talk about tracking efficiency. What exactly is this tracking efficiency? How different is it from reconstruction efficiency?
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1answer
58 views

What is the actual significance of increasing efficiency of a detector?

Say, I have a gamma detector with a 80% detection efficiency. And I buy a new one, with 85% efficiency, or even 90%. How exactly does it benefit me to be having 10% greater efficiency, other than to ...
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1answer
51 views

Is it valid to compare experimental data and theoretical data like this? Does the vertical axis of the graphs have to correspond?

The plotted curve is the experimental value of the SPD curve. Though it doesn't look "spikey" as it should, stacking the image on top seems to explain that the data is infact correct, but that more ...
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2answers
54 views

Peak at zero in one device and not the other

I was wondering if anyone could shed some light on this problem. I have placed two accelerometers on an animal one sampling at 50 Hz the other at 100 Hz. They were placed in the same position. I then ...
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2answers
826 views

Using Audacity to generate power spectral density [closed]

Say I record something with a sound recording program like Audacity (e.g. plucking a guitar string). How could I use that recording to plot a dB vs Frequency graph?
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2answers
59 views

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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1answer
1k views

What are signal efficiency and background rejection?

Recently I came across the terms signal efficiency and background rejection (for example in this paper), but I couldn't find an understandable definitions to those terms and how they are used. ...
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2answers
708 views

Least Squares Fitting - 68% Confidence Interval

I am fitting a linear polynomial to some data and I have derived the errors for each of the best-fit parameters from the covariance matrix. I would expect these errors to correspond to a $1\sigma$ 68% ...
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2answers
30 views

Interpolating experimental data correctly (limited model knowledge)

I have data which I know follows a function $y = f(x)$ such that it is quadratic i.e. $y =\alpha x^2$ for some $\alpha$ when $x\rightarrow 0$ and $y = \beta x$ for large $x$. The data itself has ...
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2answers
45 views

How does my reference point affect the regresion of data about Hooke's law?

A vertical spring is used (subject to a universal support) whose length is $20$ $cm$ when no force is acting on it. We put on a weight of $1$ $N$ and the new length is $22$ $cm$. When writing the data ...
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1answer
930 views

X-ray diffraction on thin film

As far as I am concerned, when we perform an X-ray diffraction experiment using a Bragg-Brentano diffractometer using the "powder method" we have that the scattering pattern depends on only one angle ...
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2answers
206 views

How to find gravitational acceleration given $k$ in a power function

I have a problem that has been bugging me for a week, and I can't figure it out. We know the power function: $$ y=kx^n $$ I also have a set of data: I took the natural log of both of these data to ...
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952 views

Function for curved line in log-log-plot

I've done experiments on the thermo-viscoelasticity of liver tissue and the following results ...
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2answers
1k views

1/r Counting Rate for Radiation Experiment

In an experiment performed in the lab, I want to justify that, when the width of the Geiger counter window is approximately the same size as the distance between the window and a mildly radioactive ...
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2answers
35 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
73 views

Origin of XRD Peak Asymmetry

I have been doing an introductory XRD experiment in which we measure the crystal spacing of a simple lattice (LiF) and as usual obtained data for intensity against two theta. Ideally the peaks should ...
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1answer
58 views

Determining Threshold Voltage and Plateau from experimental data

I’ve been trying to figure out how to interpret the following data from the Geiger muller tube There are only seven data points. Where does the plateau begin? Has the data collection begun after the ...
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1answer
28 views

How to find average in this case?

If we have 10 trials of measuring density each repeated three times. How can we find average? Do we take the average of each trial and then find the average of the averages? Would this be physically ...
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1answer
141 views

Choosing curves in data fitting [closed]

I have got a series of data points in experiments. And now I am trying to do some fitting job. What kind of curve should I select for this if I don't know what the exact expression is?
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1answer
19 views

Why does natural counting with a gamma spectrometer differ from Neutron activation analysis?

As stated in the title, why are the data from natural counting using s gamma spectrometer different than the data from neutron activation analysis using the same samples?
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2answers
122 views

How to find time when temperature crossed certain threshold?

I have a data from experimental system concerning temperature of molten lead. In this system, temperature is increased in one place and then is measured when this increase of temperature travels to a ...
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1answer
76 views

How to derive time derivate of strain?

Data Time(s) Strain ----------------- 100 0.31 200 0.52 300 0.74 400 0.92 500 1.10 600 1.28 700 1.46 800 1.64 900 1.82 1000 2.00 I want to deduce $\dot{\...
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1answer
342 views

Nuclear explosion wavelength data

I am looking for data source (or chart) of spectral data that is being emitted on detonation of nuclear or thermonuclear explosion. Reason I am looking is to see if this data has specific signature ...
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1answer
556 views

Dealing with experimental data

I have some experimental data about a value $n$, now, I am supposed to give, in the ending, a single value with an error: $n=a\pm b $. I have originally 6 values of $n$, each one comes as an indirect ...
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1answer
465 views

Analysis of the impulse of 2 colliding carts under the effect of magnetic repulsion

Hi there! I have a question about an experiment that was conducted. It is related to momentum. 2 carts were put on a track on opposite sides. They were then propelled towards one another at ...
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2answers
411 views

Microsoft Excel not graphing $x = y^{1/2}$

The experiment was relating the period of one "bounce" when you hang a weight on a spring and let it bounce. I have this data here, one being mass and one being time. The time is an average of 5 ...
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1answer
435 views

Implementing a black-body using Planck's Law in a 3D ray tracer

1_ In one of my software projects, I need to implement Planck's Law in terms of wavelength. I can't be sure if it's right because I've seen different variations of it, and all the implementations ...
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1answer
207 views

Filtering and extracting turbulent data from instantaneous dataset

I have collected data on flow velocity at 1 Hz sampling rate for 25 hours using a high resolution acoustic Doppler current profiler (HR-ADCP). how I can decide up to which period is the mean velocity?...
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1answer
58 views

For my Kater's pendulum experiment, why does my g vs. time look like this? [closed]

For my Kater's pendulum experiment, why does my g vs. time look like this?
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12 views

Fitting Beta Emission spectrum data according to fermi function

I was trying to fit beta emission spectrum data to the equation $$\tau(E_e) \propto (E_e^2 - m_e^2 c^4)(Q-E_e)^2\frac{E/c}{\sqrt{E_e^2 - m_e^2 c^4}}.$$ However, on making a custom equation in Origin,...
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28 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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17 views

How to physically interpret concave multifractal spectrum?

I try to investigate the damage of the metal surface with box-counting method (input data is SEM surface images) - some surfaces give a convex multifractal spectrum [f(α(q))=α(q)*q-τ(q) versus α(q)] ...
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32 views

Get the number of counts from a Gaussian that fits the logarithm of counts

I have n data to fit: $$x=[\text{channel}_1,\text{channel}_2,\dots,\text{channel}_n]$$ $$y=[\ln(\text{count}_{1}),\ln(\text{count}_{2}), \dots,\ln(\text{count}_{n})]$$ I'm considering a spectral peak ...
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26 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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16 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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2answers
57 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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0answers
31 views

Signal parameter estimation in PyCBC

I have a gravitational wave signal (strain vs. time). And I want to find out the corresponding parameters of the compact binary. But I do not know how to create injection for this signal in PyCBC. ...
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21 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
30 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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15 views

Visually comparing variances

I have a dataset containing 8 categories, I now want to visually compare the variance between the categories. The most common approach would be to use box plots or violin plots but I would like to ...
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0answers
26 views

Why is this version of Fourier deconvolution justiifed?

As I understand it, one typically performs Fourier deconvolution for the data produced by some instrument of a linear system by: Taking the observation of some unit impulse signal $m$, with the ...
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0answers
49 views

How to Mathematically Compute Spectral Power Distribution for Each Visible Wavelength in Spectrum?

I'm a CS student and been working on a conversion program that includes computing Spectral Power Distribution (SPD) from each visible wavelength in color spectrum. Here's the formula : $$X = \int_{...
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0answers
28 views

Observed Data for Asteroid Lightcurve

I am looking to find out more about writing statistical analysis programs in python for astronomy problems and was recommended that I could analyse asteroid light curves for an introduction into the ...
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45 views

How to fit mean squared displacement data from nanoparticle tracking analysis?

I am trying to independently analyze raw nanoparticle tracking analysis (NTA) data, but my diffusion coefficients calculated directly from x and y pixel values only moderately correlate with reported ...
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1answer
119 views

Double slit experiment/ fitting data to complicated sine function and vice versa [closed]

As part of analysing the double slit experiment, I've recorded position values for a number of minima and the central peak position. Also, I've conducted a single slit experiment (with unknown width)...
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1answer
41 views

What do the points on a Dalitz plot represent

I have read that a Dalitz plot is nothing but the plot of $m_{12}^2$ vs $m_{23}^2$, and that the dots correspond to "events". However, this doesn't really tell me anything. My question can boil down ...
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49 views

Correlations and associativity

Suppose one has a set of data $D$ and a theoretical model $M(A,B,C)$ one wants to fit to it by obtaining the best fitting values of the parameters $A,B,C$, which in principle are free. Plotting the ...
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64 views

Uncertainty of interpolation when covariance matrix is given

Assume that there is a given covariance matrix of an evaluated quantity ( in my case it's a rection cross section $\sigma = f(E)$, where $\sigma$ is the cross section and $E$ is each energy point ...