Error Definition and 998 Threads

I am confused about calculating errors. I have learned if you take the variance covariance matrix \Sigma_{ij} of a fit of function f(x,p) to data for parameters p_i (for example by using Levenberg-Marquart) that the one sigma error interval for p_i is \sigma_{p_i}=\sqrt{\Sigma_{ii}} I only...

I'm being asked to calculate the error on a beat frequency. The beat frequency was found to be 1/20.0s The equation given is The thing is I am not really sure where to go from there or how to get the derivative of that, any help or pointing me in the right direction would be...

hi i am having a bit of a problem understanding the steady state error in proportional controllers.. The output from a P type Controller is proportional (u=kp(error))to the error so why does this error arise?? The output from the controller tries to achieve the S.P. Once the O/p = SP the...

Laplace Error in a Circuit ! Hello as you see this circuit i want to find the v(t) across the 2ohm resistor.(VC(0-)=0) i assume A node above the capacitor , so we have (in Laplace) so i have so A=0 ! or S=-3/2 ! what can we understand about A=0 or S=-3/2 ? what is their inverse...

So I have been trying to write a code which calls from REFPROP subroutines to get thermodynamic properties and then uses these to do some other calculations. I am facing two issues: 1) The REFPROP subroutines require IMPLICIT definitions so I can't say IMPLICIT none at the top, and this may...

Hello, I'm new to Microsoft Visual Studio and new to the C++ program. I just installed the program and I'm trying to write my first program. First error that I get is: ========== Build: 0 succeeded, 0 failed, 1 up-to-date, 0 skipped ========== Why is my project out-of-date? Second...

1. Homework Statement : The expressions you obtained for acceleration and drainage time (equations 3 and 4 in the manual) both contain the following factor or something equivalent: (D/d)^4-1 In the lab, we will be dealing with a bottle with a diameter around 9 cm. A typical diameter of the...

Hello all, Recently I've found something very interesting concerning Taylor series. It's a graphical representation of a second order error bound of the series. Here is the link: http://www.karlscalculus.org/l8_4-1.html My question is: is it possible to represent higher order error bounds...

Greetings, In atomic spectra experiment I came across with error propogation in the nonlinear equation: \lambda=d\times\sin(\theta) which gives the wavelength when first order constructive interference is observed at a given angle with respect to the normal of the plane of the grating. The...

error in defined expression for Fresnel equation in MATLAB (urgent please )?? hi i have code for plotting Fresnel equation but there's something i didn't understand it and gives error >>((( plotopt - plotting option (type 'R' for plotting reflectivity, % 'A' for absorptivity or 'RA'...

Why do you have to use a homogenous mixture in an experiment what are the disadvantages of using a heterogenous mixture?

Homework Statement See attachment. I am only concerned with part b). Part a) is solved. Homework Equations The Attempt at a Solution See attachment. The solution is quoted to be tan-1(μs) = θ0, but, as can be seen by my solution, this is impossible based on the derivation. Is...

Not sure if this is a notation error or an algebra or if I am wrong , but my book presents a system of equations and I cannot get it into the form which it is presented \tau _b = \left(1 + \frac{\Phi _b}{c^2}\right)\text{ }\text{$\Delta $t} \tau _a = \left(1 + \frac{\Phi _a}{c^2}\right)\text{...

Homework Statement I am using a value of change in y say 12.10 cm + or - .06cm. I am trying to find velocity using the formula v= sqrt(2*g*change in y) how do I evaluate this equation with my standard error? because I can't just add or subtract the .06cm after since I will have a...

Hi. Let X_1 and X_2 be independent random variables with mean  μ and variance σ^2. \Theta = ( X_1 + 3X_2 ) /4 a) is it unbiased? b) what is the variance of the estimator? c) what is the mean squared error of the estimator? since there are four things, divided by 4...

Hi! How do I approximate the integral \begin{equation} \int_0^{\infty} dt \:e^{-iA(t-B)^2} \end{equation} with A, B real, A > 0, and B=b \cos\theta where 0 \leq \theta < 2\pi? I guess for B\ll 0 the lower limit may be extended to - \infty to yield a full complex gaussian integral, but what...

Hi, I have problem with the calculation the error caused by the lagrange inversion. Hence, accroding to Lagrange theorem if f(w)=z it is possible to find w=g(z) where g(z) is given by a series. I wonder, if I consider up to N-th term in the Lagrange series, what will be the error caused by...

Hello I've measured some data, let's say f±Δf as a function of x±Δx, and I know the form of f(x) but not the specific parameters, so it will be something like f(x) = (A/x)*exp(-B/x + C), I think. I'm comfortable enough fitting the data (x,f) to the curve and finding A,B,C, but can anyone point...

For a physics project, a few friends and I got ahold of a couple of balls that would record the time of an impact. Using this, we wanted to calculate g using kinematics to see how off we would be from the expected 9.81 m/s^2. Obviously, differences in altitude, air resistance, and experimental...

#include <iostream> #include <cstdlib> #include <cmath> using std::cout; using std::endl; using std::cin; double sort(double input[], int N) { double temp; int i, j; for (i=0; i<=8; i++) { for (j=i+1; j<=9; j++) { if(input[i]>input[j]) { temp=input[i]...

How may the error on the half life (using Poisson) be calculated? Barlow states that the error on the log would be 1/√N. Why is that?

How may the error on gravitational acceleration (g) be determined, given a set of measurements of time (t) and distance (d)? It is stated that the distances are measured precisely and time with an accuracy of 0.01 sec. I have applied Least Squares on t = √(2/g) * √d and found (σ of √g) albeit...

I'm teaching one of the physics labs for non-science majors at my school this year, and I ran across a formula in the first lab that's confusing me. They are using an oscilloscope to measure the wavelength of sound at a given frequency in order to determine the speed of sound. The lab manual...

Homework Statement For x near 0, local linearization gives the following equation. e^x ≈ 1 + x Estimate to one decimal place the magnitude of the error for −1 ≤ x ≤ 1. Homework Equations The Attempt at a Solution I'm no exactly sure what to do here to be honest, but what I thought I'd...

Homework Statement If the three quantities; mass, diameter, and height for a cylinder are measured with the same percentage error, which would contribute the most to the error in the density?Homework Equations ρ=M/V ρ=4*M/(pi*d^2*h) The Attempt at a Solution so, I tried to answer it like...

Hi, I am new to FORTRAN and trying to debug/compile some code passed on to me. 2 questions: - What purpose does SUBST or DSUBST serve? - When I run my Makefile I keep getting the following error: 'PGF90-S-0026-Unmatched quote' According to the PG manual this translates to 'Integer...

Dear all, I'm write code in Fortran language when compile my program I got error message : forrtl: severe (71): integer divide by zero Image PC Routine Line Source f0511 00000000007536A5 Unknown...

Homework Statement The Attempt at a Solution Thus my answer is N = 20. I wasn't sure if I should use ≤ or just <. Also to get 2 decimal place accuracy would using 0.005 be correct?

Hello, I have the third edition of Goldstein which I have been using to learn mechanics. I believe I have found an error in the book, however normally when I feel such things I tend to either be misreading the situation or misunderstanding the concept. I checked Professor Safko's site on...

Homework Statement The wiki page says that error function \mbox{erf}(z) = \int_{0}^{z} e^{-t^{2}} dt is entire. But I cannot find anywhere its proof. Could you give me some stcratch proof of this? Homework Equations The Attempt at a Solution I've tried to use Fundamental Theorem...

Hi there, Not sure if this is the right place to post, but I seem to get a runtime error that says: address out of range 0x00000000. I think that it's probably in the first three lines of my code, but any idea as to what else it may be? Thanks so much! .data save: .word 1,2,4 size...

Homework Statement "You are measuring the density of a metal sample. You have determined that the mass of the sample is 63.8 grams, and your error in this result is plus or minus 0.1 g. The volume of the sample is 8.8 +/- 0.1 cm^3. What is the maximum error (in g/cm^3) in your measurement of...

Hi guys Have lurked the forums for a while but this is my first contribution. I am in first year physics at uni and I was having a discussion with my tutor regarding the relative error for an experiment (circular motion / moment of inertia). (I tried searching for an answer to this with no...

hey all, in this link :http://gallica.bnf.fr/ark:/12148/bpt6k7258/f122.image The equation 2b is not correct I believe. Please correct me if I'm wrong. Here we go : The equation mentioned reads : Rαβλμ Rαβλρ = 2 * 1/8 * Rαβλμ Rαβλμ gμρ Now multiply out by gμρ on both sides and elevate the μ...

So I am making a module to run in the main program. The module contains a subroutine and several functions. I want to call one of the functions into the subroutine but it is not getting recognized. I am just doing Real :: fct %fct is the function name that returns a real value but when...

So we are estimated derivatives using a three point formula in class and the giving bounds for the error. I was given a table of x1=1.1, x2=1.2, x3=1.3, x4=1.4. I have to find an error bound to estimate the error for x=1.1 and 1.3 for f(x)=ex In class we did x=1.1 as follows...

This isn't so much a H/W question, but we have 2 sets of values, T[SIZE="1"]Max and T[SIZE="1"]min. Δ is the difference between them. We are told to get Δ/2 and get the %uncertainty of this. Why do we halve Δ?

[FONT=Cambria]Problem: [FONT=Cambria]Use the Lagrange interpolating polynomial of degree three or less and four digit chopping arithmetic to approximate [FONT=times new roman]cos(.750) using the following values. Find an error bound for the approximation. [FONT=times new roman]cos(.6980) =...

here is a screenshot from one of my lectures talking about how to find active power (P) and reactive power (Q) He calculates P using 100*10 Cos (30-(-30), which I understand, though the answer he gets is 200W, but whenever I calculate it I get 500 because cos60 = 0.5 and 0.5*1000 is 500...

Hi all, I have a general question about relative error. Suppose that we have a vector of measurements \hat{b}=\left(\hat{b_{1}},\hat{b_{2}},...,\hat{b_{n}}\right). Furthermore, suppose that these measurements are accurate to 10%. My natural interpretation of this statement is that there is...

Hi all, This is a homework problem, but I don't think asking for help here presents any ethical issues. I'm permitted to consult my classmates and compare solutions with them as long as I do my own work, and I plan to ask my professor for help if I still feel unsure after reading your...

Hi Guys, I am just starting readings on machine learning and came across ways that the error can be used to learn the target function. The way I understand it, Error: e = f(\vec{x}) - y* Loss: L(\vec{x}) = \frac{( f(\vec{x}) - y* )^2}{2} Empirical Risk: R(f) = \sum_{i=o}^{m} \frac{(...

I am running a mac os x 10.7 system I am writing a fortran code which compiles, however, whenever I run my code (./file.out) all I receive in return is the message "Illegal Instruction". I have tried messing with my code and I continue to receive this message. Any help with this would be...

please help by telling me whether my approach to solve the problems are right or wrong. please refer to the ATTACHMENT for the questions and my approaches... your help is highly appreciated!

I have problem regarding the propagation of error since the equations involving mixtures of multiplication, division, addition, subtraction, and powers. Please help me to clarify whether my attempts are right or wrong.

I read somewhere that the error incurred from approximating the Fermi surface to be a sphere in k-space goes as 1/N where N is the number of electrons. So, N is generally of the order 10^23. I couldn't figure out how they came up with the value. I was trying to say that the actual shape of the...

I ask this question only to those who read or have this book: If you have Baby Rudin, it would be even better. On the page 34 of the text Conway's Functions of One Complex Variable Vol 1, it proves the Chain Rule but it seems the proof is not valid: It uses sequences to show the limit is...

Homework Statement Problem 2.2 An acre is defined such that 640 acres = 1 mi2. How many square meters are in 1 acre? Homework Equations Solution From Table 2.1, 1 mi = 1.609 km = 1609 m 1 acre = 1/640 mi ^2 The Attempt at a Solution My solution comes from wolfram alpha 4286 m^2 BOOK...

Physics help please -- Sources of error in lab experiments Ok so i need some help with a few labs.. some I've tried out and a few i just can't get.. what i want to know is whether the limitations and sources of errors that i wrote down for each of these labs are correct or not and what i could...

Hey everyone, I'm not sure if there is an effective answer to my problem, but here goes: I am working on Ramachandran plots for short peptides (3 amino acids long). For every snapshot of the protein (this would be my data point) there are two angles being recorded, the phi and psi angles...