Questions tagged [data-analysis]
Use for question relating the the techniques of data analysis.
457 questions
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Propagation of uncertainties when resampling a discrete signal [migrated]
I have two discrete signals [(x,y) are the coordinates of each point] which have been sampled in different times. I need to have both signals sampled the same. What I thought to do is: interpolate the ...
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How can I detect when a car makes a turn using velocity vectors and account for speed?
I am trying to detect when a car makes a turn by analyzing its velocity vectors over time. Each velocity vector is represented as:
$$\vec{v_t} = (X_v, Y_v)$$
Currently, I calculate the change in ...
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1
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Linearized or nonlinear least squares for Arrhenius: mitigating heteroscedasticity
I have a question that is essentially expanding on this older question, but digging into a specific aspect of it that was not directly discussed
Suppose I have data points that fit an Arrhenius trend:
...
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Different results for a measured specific rotation when calculated via slope of the plot and by averaging
I have done this Laurent half shade polarimeter experiment, I calculated the average specific rotation $S_r$ by averaging values of $S_r$ corresponding to different angles of deviation for different ...
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What would the unit for the slope of a graph where the $x$-axis is mass and the $y$-axis is the drag coefficient?
I have written a paper on the effect of change in mass on the drag coefficient of a ping pong ball. While making my last calculations, I decided to use the slope of the final graph (where the $x$ axis ...
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Verifying Hooke's law through video analysis in a dynamic setup
For educational purposes, I am attempting to experimentally verify Hooke's Law using a dynamic setup analyzed through video footage. In this experiment, a body of mass $m$ is accelerated by a spring. ...
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Why does a graph of radius vs velocity of an object undergoing circular motion have a quadratic slope? [closed]
I'm doing a project with uniform circular motion and I cannot for the life of me understand the conceptual side of the graphs. On a graph of velocity vs radius of a bob undergoing uniform circular ...
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Can I change $4 \ \text{cm}$ to $4.000 \ \text{cm}$ if I want to divide it by $0.127$ to make it appear in $4$ sig figs?
I need to write a report on angle and length. Can I change, for example, $4 \ \text{cm}$ to $4.0 \ \text{cm}, \ 4.00 \ \text{cm}$ or $4.000 \ \text{cm}$ as I like if I want to make the division sig ...
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Noise in gravitational wave detections
I'm reading a paper (https://doi.org/10.1103/PhysRevD.49.2658) in order to understand the use of Fisher Matrix in gravitational wave detection. I'm a bit confused with the assumptions they do about ...
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Optimizing simulation parameters to fit to data
Good day everyone, not sure if its the right place to ask, but any help would be greatly appreciated!
As a quick explanation, I am working on spintronics in epitaxial systems. The usual methods of ...
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How to compare XRD data from literature?
I'm a grad student. Trying to do a literature review this summer. My advisor is telling me to gather XRD data of my samples for my research, and I have. Unfortunately, I have no idea how to compare it/...
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How to extract the "matter fluctuation amplitude" from the CMB power spectrum?
How do you convert the value listed in Planck 2018 results. VI. Cosmological parameters, $A_s = 2.101\times10^{-9}$ to the value of the matter fluctuation amplitude $\sigma_8=0.8111$? I tried ...
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What relationship between the time recording length and the frequency bandwidth?
In model testing for ocean waves, the data recording duration is usually longer the better especially for irregular waves. The recording length shall be long enough to achieve sufficiently small ...
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Plotting curves of diode current against temperature
I have done I-V measurement at different temperatures on a diode, now I am trying to plot the $I_D$ vs temperature curve but varying $\eta$ (the ideality factor). I am not sure of the procedure though....
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Where can I find spectra data and light curves of a stereoscopic binary star system?
I am trying to find a suitable source of spectra data and/or a light curve of a binary star (no exact star in particular), with which I would use to find velocity and period, and then find masses etc.....
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Statistics on Cauchy Distributed Data
So the Cauchy/Lorentz distribution is often used to describe distributions in physics (e.g. resonance). But theoretically, the Cauchy/Lorentz Distribution does not have a defined mean and variance, ...
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Does it make sense to whiten the data in order to apply a matched filtering algorithm if my dataset consist of a sinusoid + random Gaussian noise?
With a Python program I generated a sinusoid signal and I added to it Gaussian noise.
Now I want to compute the optimal SNR by applying a matched filtering algorithm.
Since the noise is white (at ...
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Wave vector components from 2 column data
if I have 10 data in each column for speed (2D), how to connect those data as wave form?
I need to find the components of wave vector ($k_x, K_y$).
I request any suggestions regarding this.
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Finding wave vector using Data
I have 50 data for each velocity components ux, uy in vector form in two columns. so $\mathbf{U} = u_x\hat{x}+u_y\hat{y}$.
Moreover, $\mathbf{U} = \mathbf{U_0} + \delta \mathbf{u}$ where the ...
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Interpreting non-normalized covariance matrix eigenvalues as physical Actions
Summary: Eigenvalues of a "non-normalized" covariance matrix of time-series measurements from a linear system have units of Action (energy * time). Can we interpret this to obtain ...
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Spinning gyroscope loses weight?
I ran two tests with a toy gyroscope spinning on a weighing scale that is accurate to $1$mg.
The scale was reset to zero before the tests. The gyroscope was flipped over between test $1$ and test $2$. ...
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What is a simple way to estimate $σ_{RV}$ assuming photon noise in radial velocity measurements?
Hello there i have been trying to figure out what is wanted in the question "Simple way to estimate σ_RV assuming photon noise" for a presentation. But i can not seems to find much, but i ...
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What experimental data do we have to plug into the Standard Model for it to work?
In the formulation of the Standard Model, I've always been told that we need experimental data to fix some parameters. What are these parameters and how vital is it that we have the exact value? In a ...
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In a uniformly accelerated motion experiment, the acceleration can be attained from $V_{ave}$ vs. $t/2$ and $x$ vs. $t^2$ graph. How is this possible?
Specifically, in the experiment, we had to release a glider from an inclined plane (that had an angle of inclination of 10 degrees). We had to calculate the time it reaches the final position. We had ...
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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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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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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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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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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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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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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 ...
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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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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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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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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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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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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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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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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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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. ...
