Data sets Definition and 32 Threads

  1. ForTheLoveOfPhysics

    B Data needed - Related bodies and their stats

    I’m analysing the gravitational relationships between different mass astronomical bodies and am getting sick of having to individually google and document these. Are there data sets out there that list pairs/sets of objects which includes their mass and distance from each other? Including...
  2. C

    I Finding a Rational Function with data (Pade approximation)

    Dear Everybody, I need some help understanding how to use pade approximations with a given data points (See the attachment for the data). Here is the basic derivation of pade approximation read the Derivation of Pade Approximate. I am confused on how to find a f(x) to the data or is there a...
  3. Wannabe Physicist

    Computing Errors when Data Sets are Given

    This is for the lab report I have to submit. ##n## is the refractive index. ##L## is the length of a gas chamber and ##m## is the number of fringes passed as the pressure in the gas chamber changes by ##\Delta p##. We are already given the error in ##L##. I performed the experiment and obtained...
  4. C

    Mathematica Chisquare fit to multiple data sets

    I am looking to perform a ##\chi^2## fit to more than one data set in mathematica, I just wondered how one would set this up? Given some non-linear ansatz function ##F## depending on some parameters ##a,b,c## to describe all sets of data, i.e ##F = F_z(x,a,b,c)## I want to do a ##\chi^2## fit...
  5. B

    I Data from a delayed choice quantum eraser experiment

    Hello! Does anyone here have raw data from a delayed choice quantum eraser experiment that you wouldn't mind sharing? Ideally, data from all the detectors, not just coincidence counts that the analysis usually focuses on? Or, are you aware of any data repository where data from quantum physics...
  6. Z

    B Creating Equation Based on Data Set of x,y Values

    I'm attempting to reclaim lost knowledge... hopefully this works. I would like to take a data set I have x,y values and project the trend beyond the (10) values I currently have. For example, I have a graph with (10) values for x and y, but would like to graph the trend created by values 1-10 to...
  7. W

    I How to compare two data sets with multiple samples

    I have two data sets A and B which correspond to two different settings of the system. Both sets contain 5 separate lists of integers; I took 5 samples, at different points in time and location, for each set to reduce the random error in the data. How would I go about comparing sets A and B? If...
  8. Josh Terrill

    B Linear regression with two data sets?

    I want to try to predict the USA summer highs using a linear regression. I know I can probably take data from the last 10 summers and plug that in, and use that to predict, but I'd like to use two data sources. 1 data source from the historical highs from past summers in the USA, and the 2nd...
  9. S

    Why isn't my hash set doing a good job?

    So I created my own implementation of a hash set of strings and am XORing the characters as a hashing function: private int _GetBucketNumber ( string s, List<List<string>> Buckets ) { // s: string whose index to look up // Buckets: source buckets...
  10. R

    Fun maths question, correlation?

    Say i m in the cinema and there are 4 seats. say the closest seat is the best view which is 4 meters away. say the further the distance away the worse the viewing quality. eg [5,6,4,9] are the distances of seats away from screen. Now let's say people sitting in front of you also effects viewing...
  11. E

    How to compare two data sets with statistics?

    I have two questions: I have a set of data, a measured spectrum. When I model the spectrum with a function, I calculate r2=1-(\sum(y-ymodel)2/\sum(y-yavg)2). Q1) However, I have reference data now, which is what the spectrum should be. So is it right to use the same calculation on it for...
  12. R

    Statistical significance in experimentally obtained data sets

    I have a set of data that was recorded from an engine that we are testing. We've noticed lately that a particular pressure value will sometimes spike with no apparent explanation, as seen in the attached graph. The pressure in question is passively regulated by a pump, but it is also dependent...
  13. N

    MATLAB Analyzing Wall Thickness vs Force Data Sets

    Attached are three figures. The problem in question essentially involves extracting data from a .CSV (MS Excel) file and .mdb (MS Access) file which I have done already but not correctly. Data set #1: gives me 'Wall Thickness vs. Time' ( [3400 - 8200] s , [0,1] in.) as shown in figure3.jpg...
  14. A

    Multiplying two data sets which don't have the same length or spacing

    As the post title describes, I have two data sets and want to multiply them together (and finally plot them). The problem I have is that the data are different length, so for example using Matlab: >>> data_set1 .* data_set2 But this would not give me the correct answer for a number of...
  15. J

    Calculating match between two data sets

    Calculating "match" between two data sets Hey guys, I'm developing a program for comparing the effects of various terms in a Monte Carlo experiment. Right now I have it so you can visually see the effect of "switching" terms on and off and need a way of quantifying how much two lines "match"...
  16. K

    How to correctly average over multiple data sets

    Homework Statement In a particular Magneto-Optic Kerr Effect (MOKE) experiment I have taken data for 20 hysteresis loops in which Kerr Voltage is measured as a function of Applied Field. I wish to obtain an average curve. The problem is this; Even though the settings for each loop were...
  17. R

    Mathematica Mathematica: Integrating over data sets?

    I've got a Mathematica question which might be quite basic, but I couldn't find much about it in the documentation (possibly because it's so basic) so please bear with me! I have a set of data, call it xi(ρ), which I want to integrate over some distribution function (log-normal in this case)...
  18. Z

    Comparing Best-fits of different data sets that have different noise levels

    Suppose I have 2 sets of data: day1 and day2. I want to fit a model to both data sets and then compare them to each other to see which one fits the model the best (the fit is done with a computer using non-linear least squares method). The RMS of the fit would be fine except that day1 has much...
  19. W

    Mathematica Local max/min of Mathematica data sets.

    Is there a way in Mathematica to find the local maxima of a set of points? I have a fairly fine data set, and I can clearly see several peaks in it that I would like to know the numerical value of (as in, the highest point- I don't need a spline approximation or anything too fancy like that). I...
  20. A

    Mathematica Import and plot multiple data sets in Mathematica

    I have a dat file with multiple data sets, with the following structure: # t = 0.0 , ... -10.000 0.00001 1.000001 ... -9.000 0.00002 0.900001 ... ... 10.000 0.00005 1.000001 ... # t = 0.2 , ... -10.000 0.00301 1.000203 ... -9.000 0.02222 0.900043 ... ... 10.000 0.00025 1.000551...
  21. MathWarrior

    Mathematical functions from data sets?

    I feel like I have gone pretty far in math now, but I keep finding myself asking the same question. Say I had a series of data points from like a randomly collected survey or stock stock price graph over time etc. Is there a way to take this seemingly random and scattered data and turn it into...
  22. M

    Finding Data Sets & Ideas for Neural Network Training

    I'm looking for advice. I have an assignment to train a neural network. I am confident in my abilities to write the code and train the neural network. The problems are: 1. I lack an idea. I'd like to do something interesting and potentially useful, obviously. 2. I need a rather large data...
  23. redtree

    Published data sets for distance modulus versus redshift

    Does anyone have a recommendation for a paper/source for data relating distance modulus and redshift data over a large range of redshift, such as 0 < z <= 5? I have found that combining data from different publications can be difficult given the variety of ways that distance modulus can be...
  24. J

    Comparing Non-Uniform Data Sets

    I'm not sure my title is very descriptive, but I tried my best. I also hope I am posting this in the right forum. If not, please let me know. (I thought it might be better posted in the social sciences forum.) I have a project where I am analyzing the results of multiple reviewers on a set of...
  25. P

    Cross correlation in two data sets of the same sample population

    I have the following problem: Suppose there is a survey of persons with two properties each (a and b). a can take a relatively small number of values (say the political inclination: Conservative, Liberal, Socialist, or Other) the other one b can take a large number of values (say: the country...
  26. 2

    How Accessible Are Data Sets from Peer-Reviewed Journals?

    I asked this in the mathematics section, but they told me it was probably best to ask it in a different PF section. So I'm interested in getting a hold of peer-review journal articles' "original data sets". I'm curious because I want to play around with data for fun on some statistics software...
  27. cepheid

    Comparing data sets of different sizes

    I have two data sets, each having its own array of x values and its own corresponding array of y values. I want to divide the y-values of two data sets. The problem I am having is that the x arrays for the two sets have totally different spacings (bin sizes). One set has 4175 data points...
  28. cepheid

    Comparing data sets of different size

    I have two spectra that I'd like to compare. One is the observed spectrum of HD 93521, an O-type star commonly used as a spectrophotometric standard. The other is the known, instrinsic spectrum of this star. By dividing the observed spectrum by the intrinsic one, I will be able to deduce the...
  29. E

    Two data sets and want to do a regression excel y = C(x^n)

    I have two data sets and want to do a regression so that the equation that relates them is of the form y = C(x^n), where C and n are constants. How do I do this in Excel?
  30. T

    Normalizing standard deviation between two data sets

    "Normalizing" standard deviation between two data sets I have a baseline set of data collected which has a standard deviation of X, and then I collected another set of the data under a different condition (different temperature), and this has a different standard deviation Y. How do I cancel...
  31. B

    Zero-Mean Data Sets: Removing Trends & Understanding Analysis

    I'm doing a course in data analysis using IDL and we're doing trend removal. This is the heading of the section I'm on: Trend Removal/Zero Mean Data Sets The exercises are easy to program, but I just need to find something that explains data analysis. I was hoping to find an...
  32. B

    Discover Engaging Data Sets: A Comprehensive Guide for Your Project

    Hey everyone, I need to do a project in which I have to present a data set and analyze it but I am just wondering if you know of any good sources where I can find Data Sets. :rolleyes: Especially if they're really interesting data. :-p Thanks!
Back
Top