Questions tagged [data-analysis]
Use for question relating the the techniques of data analysis.
442
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Can I use the Ph. Eur. definition for signal-to-noise to determine limit of detection for spectroscopic data?
The European Pharmacopoeia defines the signal-to-noise ratio (S/N) as follows:
S/N = 2H/h
Where H is the height of the peak from the baseline and h is the range of the background noise.
Now on to my ...
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How to use error propagation formula in equation with inseparable variables?
$$
R_i(t) =
\frac{\mu_{s,E_i}+\mu_{s,E_0}}{\mu_{s,E_i}-\mu_{s,E_0}}
\cdot
\frac{e^{-\rho\sqrt2\mu_{s,E_0}}-e^{-\rho\sqrt2\mu_{s,E_i}}}{1-e^{-\rho\sqrt2(\mu_{s,E_0}+\mu_{s,E_i})}}.
$$
How do I can find ...
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0
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Propagation of error from statistical error [migrated]
We have done the determination of protein abundance in two fractions (M and P) in one condition (SP).
We've done three biological replicas.
The data obtained are:
\begin{align*}
&\text{SP (...
0
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0
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Central Limit Theorem for subsamples [migrated]
I observe a set/realisation of $n$ i.i.d. $\{X_1, X_2, ..., X_n\}$.
Because of the Central Limit Theorem, I know that repeating such an observation enough times, the pdf of the mean of such $n$ ...
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7
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1
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Observation of the effect of gravity on the motion of antimatter
In a recent paper (https://www.nature.com/articles/s41586-023-06527-1), the authors state that
we find that the local gravitational acceleration of antihydrogen is directed towards the Earth and has ...
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When using the slope or area of a graph to calculate things, do the scales of the units on the axes of a graph need to be the same?
If I want to find the resistance(R) from a voltage(V) vs current(I) graph for a given wire using the relation tan Θ = ΔV/ΔI = R, do the scales on the axes need to be the same, independent of the units?...
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Good resource to learn more about background reduction CERN data analysis
So I am working on a project which involves data analysis of LHCb data and I have to plot invariant mass histograms. Where can I learn more about background reduction in my analysis. I have to use ...
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How to remove the baseline in the Raman spectrum without falsifying the spectral data. Measurement of anisotropy using SERS?
My goal is to study the anisotropy of the sample based on changes in the Raman spectrum as a function of angle. The sample was rotated around the Z-axis and changes in the spectra are visible in the ...
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What is the optimal measuring time split for limited measuring time between signal+background and background in a Poisson counting experiment?
I’m trying to figure out the best split of time between measuring either background or signal+background in a counting experiment in the case where we have no prior knowledge about the mean signal ...
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42
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Decomposing circular diffraction patterns
I have the following diffraction pattern produced by a fabry-perot etalon
The red represents the center of that pattern. Taking the mean intensity of the pattern as a function of the radius from the ...
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1
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48
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Binning in histograms
I have a spectrometer which outputs a dataset of Irradiance (Watt per meter² per nanometer) in the vertical axis vs. wavelength (nanometer) in the horizontal axis.
The fact that it is per nanometer ...
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Correlations in the Hellings-Downs curve for the NANOGrav 15-year dataset
I'm trying to reproduce the Figure 1c from the paper "The NANOGrav 15-year Data Set: Evidence for a Gravitational-Wave Background". This graph corresponds to pulsar pair correlations of the ...
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1
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Is this already an established functional relationship or have I created hodgepodge?
Last winter I started toying with the galaxy gravitational rotation curve graphs. I started modifying the exponent of $r$ that in effect change the $1/r^2$ law and therefore correct the mismatch, ...
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Project for Elementary Particle Physics Course
Good day! Are there any publicly available dataset in the field of particle physics that can be treated as time series? I am hoping to use methods in white noise analysis to somehow determine ...
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Deceleration parameter interval for LCDM model
In Plancks 2018 results, a value for the redshift at which the acceleration begun it is shown. Showing that this happen at redshift $ z=0.6 $. I was wondering if there is a confidence interval for ...
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Signficant figures of calculated values?
Consider the above table. The AS practical examination markscheme states that the signficant figures of calculated values should be the same or one more than the values it was calculated from. We also ...
4
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2
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Error analysis via two different methods
We have a quantity $a$ expressed in terms of two quantities $b $ and $c$ as $a = b/c$.
It seems to me that there are two ways of estimating the error on $a$, the "physics" ...
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What machine learning technique can help generate spectrum line profiles?
I'm trying to work with Calcium-K line profiles from the Sun.
Image for reference. Please ignore the labels on the image and note that my profiles are not in image format (more info below).
I have ...
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1
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49
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Aggregating an atmospheric gas concentration profile
I have a list of CO2 gas concentrations in the atmosphere in g/g relative to dry air according to a pressure profile. I have the top and bottom pressures for each level.
The list corresponds to a 40 ...
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21
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7
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Line of Best Fit with or Without Constant Term
Some other physics teachers and I were discussing an AP problem about a potential experiment for measuring $g$ and disagreed on the best way to use a line of best fit to analyze the data.
The ...
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2
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Count vs Count-per-channel
Hi there Wise people of the internet,
I am trying to do analysis some data gathered from a gamma scintillator setup, its stored in root.
So i have to do some coincidence measurements, and i found that ...
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How can I optimally rotate accelerometer readings so that the integrated velocity ends up correct? [closed]
I attached an accelerometer (with gyro/magnometer) to a curling rock and threw it down the sheet of ice. The accelerometer was not flat, and it did not travel significantly in the $z$ direction. I ...
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What is the difference between 7TeV and 13.6 TeV ? Why don't we just dump the low energy data and use the one with highest energy?
I saw some results from particle physics that combines 7 TeV and 13.6 TeV results but they are different. Why they are different? Why do we combine them? If we need them why did LHC stopped taking ...
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42
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Damped harmonic motion experiment, bad results but good statistics
I've done an experiment with a pendulum swinging at very small angles. I added an object with the shape of a rectangle to it, to increase the air friction to create damped harmonic motion.
This is the ...
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2
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47
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Model with very high chi squared reduced
I've done a latent heat experiment and measured the mass of nitrogen over time while applying heat. These are the results::
Which looks fine, most of the measures are in the linear fit. But when I ...
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0
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41
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Evaporation rate of Miscible Liquids
I am currently on a small individual research project researching the evaporation rate of miscible liquids and have some questions about the data that I have received and how to interpret it. The ...
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0
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What are the advantages of using an impulse function for data analysis of wave pulses?
I am processing the experimental data of wave pulses. The amplitude of these pulses is a piece of important information to acquire.
In my data acquisition, we acquire the sample data and some ...
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Fitting decay with background to find decay rate
I am trying to fit data (muon decays) to find the decay rate. The detection technique introduces a background rate of false decays uniformly distributed throughout the range of data (0 to 20 µsec). ...
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Can the standard errors in the slope and the intercept of a linear regression be used to get the uncertainty in the dependent variable?
I have bought a resistor that works as a heater when a voltage is applied to it, and the seller provided me these $ \left(V (\mathrm{V}), T (\mathrm{°C})\right)$ points: $(6.20$, $200)$, $(7.75$, $250)...
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3
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2
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Effect of reorthonormalisation step size when calculating Lyapunov exponents using the Gram–Schmidt reorthonormalisation (GSR) procedure
I am trying to determine the Lyapunov exponent using Gram–Schmidt reorthonormalisation (GSR), for a well-defined dynamical system (I know the differential equations etc). I believe I have implemented ...
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1
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447
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Significant figures and angles
We measure an angle to be -55 degrees (2 sigfigs).
Let us take the sine of this angle. We get sin(-55) (2 sigfigs). Now, since sin(-55)=sin(305), then we can also take the sin(305) (3sigfigs). Now, ...
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Is this scientifically useful exoplanet transit data? [closed]
For a physics project, I am trying to derive properties of exoplanets through their transit light curve. I tried to get the data myself, on the known exoplanet Qatar-6b.
My Equipment:
8" Newt. ...
1
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1
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58
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Uncertainty measurements done with multiple devices
so I need to calculate the volume of a cylinder. I have measured both the radius and the height with three different devices (ruler, calipers, micrometer), each of them 10 times (total 90 measurements)...
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Average of calculated quantity of discrete data
Let's say I have two discrete series of a physical quantity, current I and voltage V taken at the same time interval in a DC circuit. Now, I want to estimate the average power P over N measurements, ...
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Finding the uncertainty of a value after taking the average [duplicate]
Recently I did a measurement experiment where I measured the diameter of a piece of wire using a micrometer. I tested it 4 times. I got 0.87, 0.89, 0.90,0.90 respectively. The units being millimeter. ...
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Statistics error limit on a fitting
We are trying to analyze gamma-ray spectra that come from a neutron scattering in the soil sample. Our hope is to find the final error in the fitting parameters of the peak, which should look like a ...
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Scaling the experimental data
Suppose that we measure a quantity $A$ from a certain experiment and get:
$$ A = \bar{A\ }^{+\delta_u}_{-\delta_l} $$
where $\bar{A}$ is the mean value, and $\delta_{u,l}$ are the upper and lower ...
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Gravitational acceleration in my acceleration data (IMU)
I am trying to do gait analysis and remove gravitational acceleration ($9,81 m/s^2$) from my data.
I have used IMU (on the patient's lower back) to record acceleration, angular velocity and roll/pitch/...
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1
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Degree of accuracy to express $T$?
I conducted a pendulum experiment and here are my results:
10T / s:
( The time taken for 10 oscillations measured on a stopwatch that only shows the time to 2 decimal places. Measured in seconds )
For ...
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0
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Literature about robust standard errors in astrophysics?
Can you help me find any literature about robust standard errors in astrophysics? I found something about heteroscedasticity but they all use different methods rather then Huber-White estimators.
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How can you extract the frequency or phase velocity of a wave from this dataset?
I have a dataset giving the evolution of a wave (which has a single wavenumber $k$) over time. I have the data as a function of $y$ at a bunch of evenly spaced timestamps $t$. I want to calculate the ...
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Polynomial regression with microlensing parameters
As a hobbyist I would like to learn more about microlensing by exploring some data and performing some simple regression analysis. Based on the exoplanet archive of microlensing planets
https://...
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Why are there more opposite sign events than same-sign ones in the QCD background of three-prong tau decays?
So im dealing with three-prong tau decays. Specifically, two taus are produced via the Drell-Yan process and one decays leptonicly into a muon and the other decays hadronicly into three charged pions (...
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Where does the databases for isotope fingerprints (such as those used in gamma specs) come from?
Using a gamma spec for example, compares energy data and intensity, against known databases to try to find a match, and uses this to identify the isotopes detected.
What data are these databases built ...
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Statistical significance for longer measurement
I recently read that icecube neutrino detector measured neutrinos emmitted from the direction of NGC1068, which is a nearby Active Galactic Nucleus which has reported an excess
of neutrinos from that ...
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1
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Fitting histograms and error propagation
I am new to fitting histograms and as a result i have an issue understanding what to consider as error propagation when calculating a quantity. The following diagram shows entries for 4 different x-...
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Filtering combinatorial background in $B_0$ -> $\mu^+ \mu^- K^{*0}$ decay
We are looking to isolate a signal representing this decay from all possible background candidates produced in a pp collision in the LHCb. We have already dealt with all the peaking backgrounds (J/Psi ...
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Is my uncertainty when fitting a curve to data from an oscilloscope too small?
I was trying to measure the capacitance of a (large) capacitor using discharge decay. I saved the data from an oscilloscope while taking measurements, and it recorded about 250,000 points.
I noticed ...
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How to "classify" signals?
I have some signals and I want to classify them into different types. Signals are all sine shape signals, some might have glitches. I know I could classify them base on frequency or amplitude, but is ...
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Error propagation question
Lets say I have built a rotating device. Now I want to measure how
accurate the rotation is. For this I use a measuring instrument with a
resolution of $0.1^\circ$ with an uncertainty of $\pm0.2^\...
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