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3
votes
1answer
2k views

Where are the ice rings in X-ray crystallography located?

I threw this image of one of my protein crystal's diffraction pattern (not the greatest) on a poster, and was wondering where (what reciprocal dimension) the ice rings are located as it might be a ...
4
votes
6answers
4k views

How to guess the correct fitting function to some data?

Imagine we are plotting some date points $\left(x_i,f(x_i)\right)$ that we obtained experimentally, and that we want to know what $f(x)$ is. The way to do this is to use some software and try to fit ...
2
votes
2answers
126 views

Question about interpreting PDG particle cross section data sets' metadata fields

I have some question about interpreting PDG particle cross section data sets' metadata fields. The data sets I'm having questions for are http://pdg.lbl.gov/2011/hadronic-xsections/hadron.html For ...
8
votes
2answers
15k views

How do you find the uncertainty of a weighted average?

The following is taken from a practice GRE question: Two experimental techniques determine the mass of an object to be $11\pm 1\, \mathrm{kg}$ and $10\pm 2\, \mathrm{kg}$. These two ...
1
vote
1answer
322 views

Graphing measurements with uncertainties

I need to draw a graph of measurements of time for a ball to drop on an inclined plane, with error bars, along with lines of best and worst fit. The problem is that I need to do this on the computer ...
0
votes
1answer
179 views

Filtering and extracting turbulent data from instantaneous dataset

I have collected data on flow velocity at 1 Hz sampling rate for 25 hours using a high resolution acoustic Doppler current profiler (HR-ADCP). how I can decide up to which period is the mean ...
3
votes
1answer
681 views

Fitting to a high density scatter plot

I am trying to do a crude particle identification, using a Bethe Bloch tenchnique. Here is a plot I made from the data that I have From what I've read, the standard method to identify charged ...
5
votes
2answers
465 views

How are the HEP experiments' invariant mass plots generated?

I am experimenting and playing around with some data, and I'm having trouble seeing how to generate invariant mass plots. The data I have has a bunch of events, and variables such as ...
5
votes
2answers
887 views

What is meant by “combinatorial background” in experimental high energy physics

My guess is that they find a certain tracks coming from a certain source by "combintaorially" selecting all track pairs and finding their invariant mass. If this is true, of which I am not sure, how ...
8
votes
2answers
250 views

How to predict how much data to collect

The same question on CrossValidated Apologies if I'm being a bit vague in what follows, I've been asked to keep certain aspects of the experiment confidential for the time being. An analogous ...
-2
votes
2answers
92 views

Standards for scientific metadata in common-use image formats? [closed]

I have a bunch of JPEG, JPEG2000 GIF and PNG files that in theory could be used for some types of science analysis if there were temporal and spatial information in them. Years ago, I had looked into ...
4
votes
3answers
1k views

What are the easiest ways to get data out of a FITS file without a library?

There are FITS libraries for most programming languages (see this list), but FITS is a simple enough format that it should be pretty easy to extract data without the need for such libraries or ...
15
votes
2answers
2k views

Did the researchers at Fermilab find a fifth force?

Please consider the publication Invariant Mass Distribution of Jet Pairs Produced in Association with a W boson in $p\bar{p}$ Collisions at $\sqrt{s} = 1.96$ TeV by the CDF-Collaboration, ...
10
votes
1answer
1k views

Which areas in physics overlap with those of social network theory for the analysis of the graphs?

I am studying social networks in terms of graph theory and linear algebra. I know that physicists have published and worked a lot in this field. This causes me to assume that there are sub-fields in ...
4
votes
1answer
127 views

Reference request: statistical inference with real world (chaotic) data, e.g. climate/weather data

I'm interested in the process that goes from, for example, huge data sets of temperature, pressure, precipitation etc readings to a model of the atmosphere. I'd like to know about how much relies on a ...