Fit Definition and 347 Threads

  1. N

    [topology] new kind of separation axiom? where does it fit in?

    Hello, Just out of curiosity, where would following "seperation axiom" fit in? So far I'm only acquainted with the T1, T2, T3 and T4 axioms (and the notion of completely regular in relation to the Urysohn theorem).
  2. N

    Heat and work. Fit ring over rod, remove ring from rod

    It is desired to slip an aluminum ring over a steel bar. At 7.00° C the inside diameter of the ring is 4.000 cm and the diameter of the rod is 4.080 cm. (b) Find the temperature of the ring at which it fits over the bar. The bar remains at 7.00° C. ---- It is desired to slip an aluminum...
  3. I

    Showing that a model is not a good fit

    ok so i have some data (d) of star counts (N=181), and a model (m = b-Fo where b=5 and Fo-constant flux) I have found the chi squared value = 216 I know that the number of degrees of freedom here is N-parameters = 181-1 = 180 my question is: "show that the model is not a good fit to the...
  4. M

    What Software Is Best for Fitting Data Distributions?

    Hi. Which is the best software to use working on data fit distributions from your experience? Regards
  5. M

    Curve Fit Q: Balancing 1+m1*log(x) & 4.5+m2*log(x)

    I have two curves 1+m1*log(x) and 4.5+m2*log(x) [please see the attached picture]. I want to fit a third curve (which might of any equation), which should actually 'balance' the first two curves, so that the error is minimum. My problem is I am not able to get a initial reduced slope in the...
  6. V

    How to find curve (non-linear) of best fit?

    Given the following sets of data, find the curve of best fit x = -4, -6, 5, -6, -9, -2, 5 y = -4, -7, 3, -12, -2, 5, 7 a) y = a + bx b) y = a + bx + c cosx I can do part a by using the formula for least square methods for straight line. But what about part b? One way I can think of is...
  7. C

    Linear fit for data (resistance of a wire)

    Homework Statement The resistance for a wire with cross-sectional radius r is given by R = k/(r^2). Convert this equation to a straight line for which k can be determined from the slope. Homework Equations Equation of a line is: y = mx + c The Attempt at a Solution R = k/(r^2)...
  8. K

    Fit in some Mathematical Finance in before end of degree?

    I'll be in my 4th year of a Pure Math degree next year, and I'm think of what courses to fill up my timetable with. I'll be taking an overload, so I'll be taking 6.0 credits worth of courses (3.0 per semester). I'm only required to take 3.0 more courses in Pure Math to get my degree, so I have...
  9. Telemachus

    Mathematica Origin fit plotted on mathematica

    Hi there. I have a problem with this. I'm trying to plot a polynomial fit done with origin 8.5 on mathematica. The thing is that the polynomial plot I get in mathematica from the coefficients given in originlab don't match, and I don't know why. I'll let you some pics of what I'm trying to do...
  10. U

    Interpreting results of a polynomial fit

    I am currently working on a gamma ray spectroscopy lab in which i have just fit a polynomial to my calibration points. The calibration points are in a relatively straight line, from x=40 to x=450, and y=34 to y=1300 for the first and last end points respectively. Where X is channel number, and Y...
  11. matt_crouch

    Plotting a best fit curve over a histogram

    Im analyzing some data from a previous student I am trying to plot a line of best fit over the histogram and hense find the value of the coefficiants the files had to be loaded as -ascii so this is the code i have typed so far x=load('filename.mat','-ascii'); mean(x); hist(x,300) this then...
  12. T

    Fit with least squares, Levenberg–Marquardt algorithm

    Hello guys, I need your help with understanding a fitting Algorithm, so that I could make it in a C++ program. I have the following function: g(f; f0, phi0, a, b) = phi0 + a ArcTan((f-f0)/b) Which is a function of "f", frequency. I would like to fit this function with the...
  13. N

    How many pieces of paper will fit under the string?

    Homework Statement The Earth is a sphere with a radius of 24, 843 miles. You wrap a piece of string around the Earth so that it fits snuggly. THEN, you cut it, add 10 feet to the string, and adjust it so that it has equal height all around the world. Question: How many pieces of paper...
  14. B

    Calculate the chi-squared probability for the fit

    Homework Statement an experiment is performed to test whether the displacement D produced on a piezoelectric drive behaved linearly with the potential voltage V applied across it. The following data are obtained: V (volts) D (um) 0.1 50 0.2 101 0.3 151 0.4 198...
  15. Z

    Calculus III or Thermodynamics: Which is the Best Fit for Next Semester?

    I have made my schedule for next semester and I am unsure if I should take Calculus III or Thermodynamics (first ME course), my schedule looks like this: ENGR 213-Applied ODE ENGR 242-Statics ENGR 301-Economic Management in Engineering MECH 211-Mechanical Engineering Drawing Either ENGR...
  16. C

    Line of Best Fit for 3D scatter plot?

    Hi all, I'm having problems with something I'd like to do. Basically I have a 3D scatter plot and would like to add a line of best fit to it, I've googled this but most of the answers I get are incomprehensible to me (I'm a chemistry PhD student and my maths isn't amazing). Does anyone...
  17. N

    Goodness of Fit Test Without Uncertainties

    In what way can one do a goodness of fit test on a set of data that contains no uncertainties? I am doing a simulated data analysis assignment for a physics lab course and they provided me with data for a supposed xray spectrum for some material. The data consists of energy bins with a count...
  18. Y

    Can infinity fit in the palm of your hand

    I'm currently trying to reassess my image of the BB and the universe in general. I've been led to believe/understand that at the moment after the creation event the universe would fit millions of times within the space occupied by a single subatomic particle. However there's something wrong...
  19. W

    Where Can I Study Quantum Optics in Grad School?

    Im a undergrad here and going to finish my last 2 years of classes. Now I really have to look at what grad school programs are offered at different UCs. The problem is that I want to do something in Quantum Optics which is somewhere under experimental quantum physics, but as I look for it almost...
  20. P

    Why Do Different Least Square Fit Methods Yield Different Results?

    Hi everyone, very excited to be here and this my first post. I have a question about data fitting by using least square fit, and the problem is: I have a experimental data set(xi, yi), and I want to fit it to single exponential y, now i tried two ways: 1. do linear least square fit to...
  21. G

    How to estimate a function that fit well with a curve

    hello somme one know how to get the function that fit well with a curve following is my curve: [PLAIN]http://img814.imageshack.us/img814/5885/tempdepth.png thx..:smile:
  22. K

    Creating a Predictive Model for Time-Independent Data Analysis

    Hey all. I have some data, approximately 6 months worth. It is values that do not depend on time but are represented by a pair (x, y) such that the values x is measured at a point in time y. Therefore the data is equivalent to measuring how much stock I have in a given time period, say. The...
  23. zoobyshoe

    How Far Will You Go to Fit In? The Science of Conformity and Social Acceptance

    Before you object and declare that you NEVER go out of your way to be "cool" or socially acceptable, think twice. You may be enough on the nerdy side that you'd never get a piercing or tattoo, but, in the pursuit of that nerdiness, say, have you never bought a piece of technology or a program...
  24. R

    Which Well-Paid Jobs Fit These A-Level Subjects?

    My nephew needs a bit of help in finding 2 jobs to write about for his career plan, he knows what subjects he wants to do at a level but can't find any jobs that fit the subjects. The subjects he would like to do are, Technology and design Biology Chemistry Physics Mathematics, he...
  25. E

    Will Press Fit and Powder Coat Work Together for My Sheet Metal Part?

    Hello all, I need some help with a sheet metal part I am going to produce. The part consists of 12ga A572 grade 50 sheet metal and a 1020 or 1018 steel spacer that will be press fitted into a laser cut hole in the sheet metal. After assembly the part will be powder coated where I know...
  26. P

    How do I perform a weighted least squares fit with error bars?

    Hi, I am trying to do a best least-squares fit to a set of data which is described by the following equation: y=a\exp(-b\ln^2(c/x)) Where a,b,c are constant parameters I am trying to find values for. Any advice on how to proceed?
  27. K

    Best Fit for 2-D Shapes in Larger Shape?

    Hi, my first post here and I'm not sure I'm in the right place or that I use the proper terms so please bear with me. I'm a programmer by trade, and I'm working on a project whereby I need to arrive at the best fit for a set of 2-D shapes fitting within a larger shape. Mostly we're dealing...
  28. J

    Best fit curve using Q-R Factorization?

    Best fit curve using Q-R Factorization? Homework Statement Homework Equations The Attempt at a Solution So ... It's part (a) that is confusing me. I already factored it into Q and R. But does the Q-R Factorization have to do with best-fit lines? (To be fair, I'm working on homework...
  29. B

    How many rectangles fit in a triangle?

    Does anyone know how one could calculate the maximum number of whole rectangles that can fit into a triangle. Say you know the length of the sides of the triangle (t1,t2,t3) and the of the sides of the rectangle (r1,r2). Thanks.
  30. Simfish

    MATLAB Linear Least Squares Fit with Error Bars: A MATLAB Tutorial

    With MATLAB or something. Basically, I just have a bunch of data points where I should do a linear least squares fit, but each of the points have error bars around them.
  31. D

    How does DNA fit into the nucleus?

    Homework Statement How does a large DNA molecule enclosed in the nucleus of a cell? The Attempt at a Solution I know it has to do with histones and how DNA winds twice around it to make it shorter, but can anyone further expand on this? Thanks : )
  32. S

    How does this fit the equation of a hyperbola?

    As far as I know, a hyperbola has the equation So how does this (below) work? Thanks!
  33. P

    Memory management-worst fit algorithm

    let us suppose we use the worst fit algorithm for allocating memory...initaially when whole of the memory is available...then it allocates full memory to one single process...hence no multiprogramming possible...hence what are the advantages of this algorithm...over first fit and best fit... Thanks
  34. P

    Inverse best fit slope expected vs calculated

    inverse best fit slope...expected vs calculated Given a set of data (X,Y) pairs, we can get the best fit line using many techniques. Assume the correlation is not perfect. We can use the least squares method to get the best fit line slope and intercept. So we have Y = mX + b In other...
  35. G

    Find Out How to Determine Accuracy of Line of Best Fit

    Hi everybody I was set a homework but I don't know how to do it because our teacher didn't taught us something like that and I have looked in a lot of books I still don't know what to do. The question is how to determine the accuracy of a line of best fit. can somebody help me with that please...
  36. E

    Troubleshooting Ezyfit: Solving Fit Problems with NaN Data and Multiple Datasets

    Hello again, Part of the problem is solved. There were NaN entities in the dataset. I removed those, now a fit can be made, but still, only through 1 dataset (see figure). How to put the fit through both?? Grz. Fr@nk Hello everybody, I have a very large set of datapoints (about 500)...
  37. O

    How accurate is the correlation coefficient for log-log data?

    I am familiar with linear regression and the correlation coefficient. My current problem involves a data set that is pretty linear on a log-log plot. I have calculated the slope by taking logs of all my x's and y's, and doing the linear regression on the transformed data set. The resulting...
  38. E

    Mathematica Mathematica nonlinear fit problem

    I would like to perform a complicated nonlinear fit with mathematica, which involves a numerical integral in the fitted model. But i can't get it to work. If I say something like: NonlinearRegress[data, NIntegrate[f[x, p1, p2, y], {y, 0, 1}], {p1, p2}, x] it says the integrand evaluated...
  39. W

    120 VAC to 12 VDC circuit to fit in E27 Base

    I want to start making my own LED lighting but need to find a small footprint, hopefully pre-made circuit that fits within a E27 Base Cap. I have just searched (almost) everywhere and have decided to just ASK. It needs to be about the size of the tip of a mans thumb to fit in the E27.
  40. G

    Mathematica How do I fit damped harmonic motion data (x vs. t) using Mathematica?

    How do I fit the data given below into the standard form (ignore the part saying to use MathCad): http://screensnapr.com/u/apmqkd.png {{{0.002, 0.726}, {0.022, 0.739}, {0.042, 0.75}, {0.062, 0.759}, {0.082, 0.768}, {0.102, 0.776}, {0.121, 0.785}, {0.141, 0.794}, {0.161, 0.802}...
  41. P

    Will 1,535 ml of Water Fit in a 15x10x10 cm Container?

    Homework Statement Suppose you have a quantity of water with a volume measurement of 1,535 +/- 10 ml. This quantity of water is to be transferred into a regular orthogonal container whose interior dimensions measure 15.0 +/- 0.1 cm long, 10.0 +/- 0.1 cm wide, and 10.0 +/- 0.1 cm deep. If you...
  42. C

    General equation for press/shrink fit stress?

    Shear stresses in shrink fit assembly? I'm trying to figure out what shear stresses there would be from a shrink fit assembly, if any. You have a cylindrical solid shaft and a cylindrical hub, where the shaft diameter is greater than the hub's hole diameter. The shaft cooled and thus shrunk and...
  43. D

    Program to search for curves which fit experimental data

    Does anyone remember a program (or know of something similar!) which, given a compilation of data, would search for equations which best fit the data? The one I'm thinking of came out ~ a year ago. It was a Windows-only program but it worked fine under wine. Unfortunately my time spent on...
  44. D

    Math Ph.D. Programs (Looking for a Good Fit)

    Hi, I am applying to graduate schools this fall, and I could really use some guidance in finding a program that would be a good fit. The way I see it, there are two things I must consider: Applying to programs that may accept me, and applying to programs I would want to attend. :) I attended...
  45. A

    Finding Math Software to Fit & Adjust Curves

    I am looking for math software that will fit a set of points with a cubic spline (or other technique)...then allow the user to change the shape of the curve by dragging it...and continuously fit the curve as the dragging is occurring (or fit the curve after the dragging has stopped). The point...
  46. M

    Describing the goodness of fit of a model

    Describing the "goodness of fit" of a model Hi there, I would like to ask advice on an appropriate way to define how well a measurement 'matches up' to the predicted response. In other words, I have a set of data for bandwidth measurement for an LED (amplitude vs. frequency). I also have a...
  47. C

    Is programming a good fit for me?

    I just completed my undergrad in physics and applied math, but I liked the applied math more partly because the physics got too abstract for me - I liked classical mechanics more than quantum mechanics. As a result, I had been strongly considering getting my MS or phD in mechanical/aerospace...
  48. Saladsamurai

    ExcelGetting a Better Curve fit?

    Hey folks, Am I doing something wrong here? It just seems like I should be able to get a better fit. The data is plotted for the H2-->2H reaction data. I have attached the .xls file. Don't worry, no macros :wink: I created it on a Mac, but hopefully everything converts correctly...
  49. J

    Parabolic curve fit to x,y data

    Homework Statement Given a series of measured data points (>1000) x,y find the best fit parabolic curve where the constant A (below) is given. Homework Equations General 2nd deg equation describes conic sections: Ax2+Bxy+Cy2+Dx+Ey+F=0 for a parabola B^2=4AC, AND in this case B<>0...
  50. F

    What is the significance of global fit in EW precision tests?

    I always hear that the "global fit" EW precision test. It seems that I understand it a little. But I am still very clear. Who can shed light on it?
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