Questions tagged [data-analysis]
Use for question relating the the techniques of data analysis.
465 questions
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Why does orbital velocity variation correlate with $\sin$ of the angle between position and velocity vectors?
By analyzing the motion of Venus using NASA JPL Horizons ephemeris data (10-year span, 1-hour sampling), I found that the variation of orbital velocity $\Delta v(t)$ appears to closely follow a ...
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Clipping the covariance matrix [closed]
I want to test my anisotropic cosmological model against Dark Energy Survey (DES) data and constrain Right Ascension (RA) and Declination (DEC). The DES data, although containing 1829 data points in ...
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Statistics for Theoreticians
I'm a theoretician, and as the years pass, I notice my knowledge of statistics and my memories of experimental physics classes fading and becoming more and more uncertain. Thus, I'd like to ask for ...
3
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1
answer
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Is it okay if your signal and noise have the same statistical distribution?
Please bear with me if this seems like a very basic question. Let's say you want to detect a signal by measuring a variable $x\in[0,\infty)$. Let's say you know the variable $x$ follows a probability ...
- 673
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Numerically marginalizing over a parameter
I am working with gravitational waves data. I have done a Bayesian parameter estimation using dynamic nested sampling. So I have posterior distributions for several parameters. Now I want to ...
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When to average measurement results?
What do I want to do?
I want to measure the gravitational acceleration $g$.
To do so I measure the fall time
of an object from a height $h$, which I have measured previously up to a uncertainty $\...
- 41
4
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1
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377
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Mean time and mean velocity in example with ball running down a slope
I was reading about examples of experiments with a smooth ball over running down a smooth slope and how the concept of velocity was formed.
So as an example if we have a ball that is at $t = 0$ at $d =...
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To what extent is gravitational wave “observation” a function of model-matching?
I'm asking about the epistemic structure of the detection process — not whether gravitational waves are real, but how we decide that what we've seen is a specific event, given that the match is ...
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Monte-Carlo error propagation in divergent function
I have a function
$$
f(a,b)=\left(\frac{a}{b} - 1\right)^{-1}
$$
I have obtained values for $a$ and $b$ from two independent linear fits including errors on $a$ and $b$.
Now I wanted to calculate the ...
1
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1
answer
139
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How to interpret fusion rates data from REACLIB1?
I'm trying to model fusion in a star, and I came across a library of reaction rates data: https://reaclib.jinaweb.org/popularRates.php
The rates come as a polynomial in temperature, but the result has ...
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0
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Outstanding Cosmology Problems Needing Better Algorithms [closed]
There are/were open problems in cosmology where we have the tools necessary to study them but not enough data to use. For example, we know how to use strong lenses to estimate the Hubble constant and ...
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What's the naming convention for variables/features in ATLAS datasets?
I am working on my Master's thesis and am working with (simulated) ATLAS data - v09 Ntuples for the hypothesized tbH+ channel. I'll be using FastFrames to process the raw Ntuples and then use the FF ...
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Determination of Ohmic Resistance from Characteristic Curve [duplicate]
When trying to determine the ohmic resistance from measurements of current $I(U)$ at different voltages $U$ of a circuit with the ohmic resistance built in, which of the following methods evaluate the ...
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What is the point of using a least squares fit for experimental data points when almost all data points have varying errors in $y$?
Sorry if this is a silly question - 1st year Physics undergrad here. My question is, why does the method of least squares fitting seem so ubiquitous, given that it is always emphasised that where ...
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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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