Fit Definition and 368 Threads

Hello all, I am trying to extract the 2nd degree polynomial coefficients from a curve of best fit applied in EXCEL. I know how to do it (http://spreadsheetpage.com/index.php/tip/chart_trendline_formulas) 2nd Order Polynomial Trendline Equation: y = (c2 * x^2) + (c1 * x ^1) + b c2...

Dear All, I would like to least square fit a number of measurements using several nonlinear functions with shared parameters (similar to the advanced fitting in Origin) using Mathematica. Therefor I would be interested in an Algorithm like Gauss-Newton that fits several data-set to several...

At this point, I am rather confused about the concept of DE, and even why it is called DE since it does not seem to fit into what the concept of energy is. but my question is where/how does DE fit into the standard model? thanks.

Hello everyone, I did a quick search but could not find this in the forums. I have quite a basic situation. I have been gathering data points from an experiment and was able to fit an exponential curve of best fit to it. What I want to do is approximate some values between my data points...

determining the "best fit" regression for a set of data Is there a test one can perform to quickly determine what type of regression (linear vs. non-linear) will best fit the relationship between two variables? i.e. How can one quickly determine the most probably relationship between two...

More specifically, do the leads on a TO-220 package MOSFET (http://www.alliedelec.com/Search/ProductDetail.aspx?SKU=273-1185&MPN=IRF640NPBF&R=273-1185&SEARCH=273-1185&DESC=IRF640NPBF?utm_source=Allied&utm_medium=merchandising&utm_campaign=Allied_Top_Sellers&utm_content=273-1185") fit in the...

best fit line? DOes that mean you draw a line/curve connecting the dots? Or does that mean you draw a line in between the dots leaving some above and some below? or does that mean you connect the dots but leave out the ones that dnt fit with the shape? please help

Z(x)=(50*m+m^2*tanh((a+b*i)*x))/(m+50*tanh((a+b*i)*x)) where i is imaginary unit, x is the independent variable, Z is the dependent variable, and a, b and m are the parameters. We measures variable Z at a discrete set of values of variable x: x=[1, 2, 3, 4, ...20] Z=[57.6286+0.6328*i...

I recently completed an experiment for university level physics and am currently doing the analysis of the data. This data has been transformed to fit a linear model and it fits this very well, with the line of best fit lying within all error bars. I need to provide estimate of the gradient...

Say you are Noah and you have to put two of every animal into your ark. You don't have to worry about fish or aquatic mammals. How much space would you need on your ark. Even if you put the animals into a blender so that you could fill your ark with no empty spaces would they all fit into Noah's...

I am looking at colleges right now and I was wondering what other colleges you would suggest. I am looking for a college with a strong undergrad physics program. I got a 1100/1600 (1480/2400) on my SAT's, 3.74/4.0 GPA. I am looking for colleges close to the philadelphia area, but not in the...

Hi everybody, I have a very quick question about surface brightness profiles for an edge-on galactic disk. I have surface brightness values (V-band, not that it matters) in units of mag/arcsec^2 as usual, as a function of z, which is the distance from the galactic disk's plane. I'd like to...

Please tell me if some of you know of a way, or program that I can download or use to fit a given polynomial to a set of data. I have done an experiment in which I varied two currents thru wires (Ix, Iy) and measured the Temperature at a given point (T). The polynomial is known from a model (I...

Best fit MIN/MAX line through data. Hello, I’m working with mechanical fatigue test data. Generally this data falls in a logarithmic curve relating load to number of fatigue cycles. This data tends to be somewhat erratic so there need to be a lot of samples at multiple different loads to...

I am going to apply to colleges next year and have been told by my counselor to find a list of 4-8 schools that are "good fits." What factors should I consider to find a good fit? I can pretty much picture myself doing well at any type of school. All I am really want is an academic challenge (I...

Like the title says, if you have a bunch of data you can create a best fit line For example back in school, for a linear line, y = mx + c, you just need 2 points to get a line. But what if you have more than 2 points, say 10, what is the best fit line equation or how do you do it...

I need to calculate a line of best fit, using... The least square fit method. I am upto the stage where i have created my matrix 2 x 2, and then i have invesed the matrix 2 x 2 and then got a fraction and a [2x2] matrix. Now i am stuck. The textbook has the inverse matrix, and the...

Hi, I have a set of datapoints (x_i,y_i) and I am going to make a best fit to y = c*Exp(a/x) Making the fit isn't the problem (Mathematica, etc. can handle this), but what I need is the error on a. What I have done so far is something like this: P(c,a | {x_i,y_i} ) = k * P( {x_i,y_i}...

I have to fit a curve to predict Y on the basis of X. 50 pair of (x,y) is given. On free hand plot the curve it is seen (and otherwise known also) that Y and X has 1:1 relationship. The basic nature of movement of Y is quite composite and found involving x^a, sin(c+bx), d^x , one additive...

Well, i am taking a first course in elementary statistics, so we do not actually prove anything at all. So i was wonderign how does one determine the line of best fit? y=mx+b, where m is the slope of the line of best fit, I know that the slope is equal to m=SS(xy)/SS(x), where SS(x) is...

I'm having trouble getting the answer to this homework question: How many Earths would fit into the Sun? can you guys help me in solving it, please? Thnak you

I am currently working on a lab report for my physics class. During the lab, we used air tracks, gliders, and a photogate to measure the value of 'g'. Basically, we would raise one end of the air track to a certain height and let the glider slide down the frictionless track and the timer would...

I have five, very precise, experimental values of refractive index for five different wavelengths and would like to draw the Sellmeier fit of the form: n^2=A1+A2/(1-A3/lambda^2) + A4/(1-A5/lambda^2) So, to find A1, A2, A3, A4 and A5 parameters I need to solve the system of five equations...

Thanks to EnumaElish for helping me in Normalizing the histograms. I now want to find the best fit distribution and what will be the parameters for that distribution. I tried lograthmic but it goes in negative and also is not much fit (the new plots are attached). If I use poisson what will be...

I have plotted packets arriving in one second at a router. I then made histograms of the number of occurences of same number of packets in one second time window. My question is that I want to normalize these histograms. How can I do this to get probability mass functions. And then how do I...

1. I need to know where the Y intercept would be on a linear equation with a slope of 4 and the intercepts (-22,101) and (-12,141). I also need to know how to find the line of best fit on a calculator I think the Y-int may be 189, but I don't really have any idea how to do either of these but...

Ok, I need to take the data: D1 D2 6.5 3 6 4 6.7 5.5 7 3.8 6.3 4.5 8.6 5.8 5.5 4 7 3.5 7 4.5 7 5 6.5 4 6.8 3.2 7 3.6 6 4.5 6 2.8 and make a histogram (centered around 0 -- i.e. 0 will not be an edge of a bin) of the data...

Homework Statement I am needing to identify whether or not my distribution follows a normal distribution. Now by eye it kind of looks like it does, but I need to perform the kolmogorov-smirnov goodness-of-fit test to verify this. Below is a picture of my dataset with a normal curve fitted to...

I just heard about the Casimir effect: http://en.wikipedia.org/wiki/Kashmir_effect Is this for real? Or is it just speculation? If it's real, then how in the name of science does it fit into the four fundamental forces?! http://hyperphysics.phy-astr.gsu.edu/hbase/forces/funfor.html I...

Ned Wright's best fit standard LCDM is simply one possible concrete version of the usual LCDM model that cosmologists use. It has the normally preferred parameters (0.27, 0.73, 71) plus the estimate that Wright gave of Omega = 1.011. That's what he gave in January 2007 as the best LCDM fit to...

Homework Statement Prove the following useful fact: the least-squares fit for a line through any set of points (x_1,y_1) ...,(x_N, y_N) always passes through the "center of gravity" (x-bar, y-bar) of the points, where the bar denotes the average of the N values concerned. [Hint: you know...

Here's a (possibly very simple) question I have: How many photons can you fit into an arbitrary volume? Is it infinite because they are massless/volumeless particles? If that is the case can you fit an infinite amount of energy in an arbitrary space? (theoretically) Thanks Gareth

I have a set of points x y 0 0 1 1 2 3 3 4 4 6 5 8 6 9 7 11 8 14 9 16 10 18 11 21 12 24 13 27 14 30 That seem to define, fairly closely, a parabolic segment. How do I find the scale and x/y origin of the parabola that most closely fits these points?

...into this type system? Take the tests before you read the article, please. :smile: http://f0rked.com/articles/estheory" My scores: E = 49; S = 48 My type: S (Okay, the test is a little repetitive, so my mind was wandering while I was taking it, and I wonder how the different brain types...

Homework Statement A barrel of diameter D at 20 degrees Celsius is to be enclosed by an iron band. The circular band has an inside diameter of d at 20 degrees Celsius. It is w wide and t thick. (a) To what temperature must the band be heated so that it will fit over the barrel? (b) What will...

I'm trying to see how well my data fit a certain probability distribution (an exponential distribution) and I basically want to know how reliable is it to compare the the theoretical variance of the distribution and the variance of the data, to assess the goodness of fit of data to a...

Is it possible to make a least squares fit with a function given implicitly, because the equation isn't solveable analyticly? Because I had the coupled ODE, \ddot{x} = \omega^2x + 2\omega\dot{y} - C\,\frac{\dot{x}}{\dot{r}} \ddot{y} = \omega^2y - 2\omega\dot{x} - C\,\frac{\dot{y}}{\dot{r}}...

for example, i want to find the coeffiecients of a function f(x) = ax^2 + bx + c for these given conditions: f(-1) = 3 f(1) = 3 i tried plugging and chugging for the first condition: 3 = a - b + c 3 = a + b + c now i tried subtracting the system to get 0 = 2b so its solved that b...

Hi, should I use a line of best fit on a cumulative frequency graph or join the ponits. I looked on google and it;s all mis mashed. Is it arbituary or depend on data? Thanks

hi, this is my first post here in this forum. i would like somebody here to help me in calculating the force exerted onto the pipe by a stainless steel ring of 10mm thickness, when it is shrunk fit on to the pipe by heating. thanks in advance

Homework Statement I have a project for one of my class and I have been given a sheet to do the statistical analyst of my data. I am not convince this sheet is proper and I need someone to look over it it. I don't understand where my Delta R goes... Homework Equations \chi^2...

In his most recent, Ned Wright gives the best fit Omega as 1.011. He hastens to say that since the fit is not all that better than for Omega exactly 1, space being flat infinite, one cannot rightfully conclude that Omega > 1. However suppose, simply as an intellectual exercise, that one...

In an infinite square well potential, the ground state of a particle, has a wavelength twice the length of the well. How can the particle fit in the well then? It's not even one wavelength.

Why can't they make bras that fit right? Why are the shoulder straps so close to the outside edge of your shoulders that the straps keep sliding down my arms? I am NOT built with the shoulders of an American football player (not soccer), which apparently, is what they had in mind. Ok...

I have been given a set of questions as a pre-course task for my physics AS level and i would be very grateful if somone could check my working and tell me if I'm on the right track. One of the questions is how many atoms (with a given diameter of 0.0000001mm) can you fit into a 1cm^3 space. To...

Need best "mm" for close fit I am for the first time building an object for fabrication online with "e-machineshop" free CAD software and odering service. I would like to know what is the minimum desirable space between two objects to allow for the closest (tight) fit with the least amount...

[Please excuse this topic if it is in the wrong area but since it is so vague I threw it in here. If it is in the wrong forum please redirect it! Ill try and save a copy too!] Has anyone given the thought of someone with fresh ideas? I know so much has been done now in sciences, philosophies...

We all know the least squares method to find the best fit line for a collection of random data. But I wonder if it is the best method. Suppose we have two random variables y and x that appear to have a linear relation of the type y = ax+b. What we want is, given the next type x signal to...

I have a function y = \sqrt{ax^2 + bx +c}, and 2 sets of points {x_i},{y_i} that need to be fit on this curve. First in this problem, I need to somehow convert this nonlinear function into linear and then apply least square methods to determine a,b,c. What I came up is ofcouse squaring both...

So, yeah... this is an assignment, but i just need some hint: we need to write an abel program for a combinational logic function with 5 inputs representing integers 0-31, and two outputs M3 and M5, which indicate whether the number is multiple of 3 or 5, respectively. So, here's my...