# Questions tagged [data-analysis]

Use for question relating the the techniques of data analysis.

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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 ...
50 views

### 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 ...
32 views

### 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 (...
17 views

### 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 $n$ ...
1k views

### 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 ...
37 views

### 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?...
24 views

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 ...
23 views

### 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 ...
1 vote
42 views

### 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 ...
42 views

### 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 ...
48 views

### 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 ...
1 vote
66 views

### 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 ...
45 views

### 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, ...
60 views

### 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 ...
14 views

### 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 ...
34 views

### 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 ...
487 views

### 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" ...
1 vote
43 views

### 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 ...
1 vote
49 views

### 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 ...
1k views

### 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 ...
80 views

### 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 ...
1 vote
39 views

### 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 ...
70 views

### 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 ...
42 views

### 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 ...
47 views

### 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 ...
41 views

### 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 ...
1 vote
16 views

### 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 ...