# Questions tagged [data-analysis]

Use for question relating the the techniques of data analysis.

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811 views

### Moment of Inertia and Mass Experiement

I am currently working on a physics project to experimentally confirm the relationship between mass and moment of inertia. The experiment is setup as depicted: In this experiment, $r1$ and $r2$ are ...
89 views

### Difference between Fourier and Laplace transforms in analyzing data

I have a set of displacement-time graphs from an experiment to convert to the frequency domain. Both the Fourier and Laplace transform seem to do this, so what's the difference between them (...
361 views

### When to round off standard deviations in uncertainty propagation?

Let's take a concrete example. One is dealing with a wire through which a DC is running. One measures its voltage and obtain its current by measuring the magnetic field around it in some way such that ...
141 views

### Question when comparing two experimental results

In my textbook it says that if two experimental results vary less than 3$\sigma$ then they can be considered to have arrived at the same result. My question is how do you determine this "x$\sigma$". ...
136 views

### Data driven and MC simulated background in experimental particle physics

In experimental particle physics, we use for data analysis a set of samples to simulate the background and the signal we want to observe. When reading articles, I often encounter a section dedicated ...
239 views

### Comparison between Bethe-Weizsäcker-Model for the nuclear binding energy and measurements

I tried to compare the binding energies of between the measured data and the Bethe-Weizsäcker model. My plot looks like this and I don't understand the large discrepancy: For the measurement I used ...
397 views

### Interpretation of invariant mass distribution plots

Can someone explain what exactly a invariant mass distribuition is and how to interpret the follwing graph. Especially what Events/GeV means.
184 views

### Finding the combined uncertainty of weighted measurements

I am currently doing some simple simulations of radiation dose from several treatment fields. I am looking at the dose within a certain voxel of a patient receiving radiation therapy, being treated ...
137 views

### What is the electron energy scale calibration?

I am reading a paper from ATLAS collaboration in CERN and it is mentioned the "electron energy scale calibration" many times. It must be related to energy calibration in the experiment but I would ...
421 views

### How to implement Hubbert's potential to calculate permeability using Darcy's law?

Question: How does one implement Hubbert's potential to calculate permeability without making assumptions to neglect any aspects of the potential defined by Hubbert? Question's supplemental material: ...
349 views

105 views

### What is the correct way to handle significant figures when calculating compound uncertainties? [duplicate]

When processing experimental data, and calculating an uncertainty value in multiple steps, should intermediary uncertainties be used to a certain number of significant figures or kept to the full ...
193 views

### Curve Fitting and Multiple Experiments

Say I do an an experiment 5 times, each of which gives you a list of data points. Do I fit a curve to each one separately and then average the parameters and their uncertainties? Or do I take the ...
31 views

### Choice of color for graphs with filled area [closed]

I am writing an article and the central results are summarized in a graph so I want it to be very beautiful and physically intuitive. It has 3 regions in which a certain quantity is conserved, ...
2k views

### gaussian fitting of xrd peaks

I am reading a paper regarding the nano crystalline material with hexagonal crystal structure. In that paper in order to find out lattice parameter of hexagonal crystal structure they have fitted a ...
164 views

### More points vs. precision

I have a dilemma. In my lab exercise, I was measuring spectra with HPGe detector of several sources (gamma spectroscopy). To determine the energy of the unknown spectrum I first needed to calibrate ...
59 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 ...
48 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 ...
31 views

### 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: ...
38 views

### Mathematical Resolution of Overlapping Signals

I would like to take the opinion of physicists (my area is chemistry). During instrumental analysis, the output is a instrument response vs. time. Each peak corresponds to a molecule which is ...
62 views

663 views

### How to read Inverse Pole Figures (IPF) images

When (Electron BackScatter Diffraction) EBSD maps are procesed the output crystallographic orientation is derived into Euler map and three Inverse pole figures (IPF) maps. In the example there is IPF-...
25 views

### Data Analysis: Image Sharpening through Posterization

I had this image, a picture of Jupiter: I wanted to measure the pixel diameter of Jupiter. As evident, the image is quite blurry, and thus, many value of equally justified pixel diameters can be ...
184 views

### Normalizing temperature data of CPU sensors to ambient [closed]

My scenario: I want my application to stop or take some decision based on temperature. say like if my ambient is morethan 41 i want to switch off the application and we do not have an separate ...
140 views

### Sine wave in my residuals graph [closed]

We had a physics experiment where we should have had a linear relation between 2 measured values, we got a pretty good fir however our residuals plot has a kind of a sine wave behaviour. We were told ...
22 views

### Starter projects/visualizations/analyses? [closed]

I just renovated a desktop that had been in storage for a while and I am looking for good ideas for data analysis or numerical analysis projects in physics. I have taken up to E&M, and special ...
47 views

### Karhunen-Loeve transform of a repeating process

This question is inspired by measurements of an unsteady flow. I have some doubts about interpretation of principal component transform using Karhunen-Loeve theorem. I have (centered $\equiv$ zero ...
49 views

### Data Collection of oscillatory motion

I'd like to study nonlinear oscillatory motion this semester. I plan to build several different mechanical systems (pendula, masses on springs, etc with and without driving forces, large/ small drag, ...
76 views

### Manager for results of physical simulations [closed]

I have quite a general question. I'm phd student in the field of plasma physics, our team has developed a numerical simulation of a diagnostic method in plasma (langmuir probes), written in fortran. ...
124 views

### Looking for an Time Series Analysis Text [closed]

(Apologies, I could not think of a better title). Two days ago, I was in the Library at Köln (Those who know it, knows that the books are not ordered by subject - but by date of buying, and one has ...
89 views

### How to calculate the correct coordinates from a distorted video of a projectile?

I am working on a high school project that is related to projectile motion. I am exploring how exactly the position of the center of mass affects the trajectory of a long but thin, javelin-like ...
111 views

### Fitting of data to a model

Imagine that I have some observable value predicted with a theory for some process to be: $1+a x + b x^2$ and observed value is 1.3 with an error 0.2; a and b are some numerical constants. I also have ...
344 views

### Gamma spectroscopy - Do annihilation photons produce a backscatter peak?

Below is a diagram of part of a structure which I find in a gamma spectrum taken from a hall in which a neutron source is undergoing spallation. The structure which I'm interested in can be seen ...
88 views

### Big Data Handling at the LHC

My understanding is that much of the data that is is collected at the Large Hadron Collider is similar to that in the image below, and that a vast amount of the data contains little of specific and ...