An error (from the Latin error, meaning "wandering") is an action which is inaccurate or incorrect. In some usages, an error is synonymous with a mistake.
In statistics, "error" refers to the difference between the value which has been computed and the correct value. An error could result in failure or in a deviation from the intended performance or behavior.
Hello,
In reviewing the classical linear regression assumptions, one of the assumptions is that the residuals have a normal distribution...I also read that this assumption is not very critical and the residual don't really have to be Gaussian.
That said, the figure below show ##Y## values and...
I thought maybe we should have a thread about these software as there are probably interesting artifacts about them and they are just interesting in general
So here is an interesting fact I just found out while messing randomly with chat GPT.
I asked it a simple question - "5 best jokes about...
//program showing an advantage of using arrays
public class Arr3
{
public static void main(String []args)
{
System.out.println("There are 31 days in the month of Jan");
System.out.println("There are 27 days in the month of Feb");
System.out.println("There...
When trying to compile the following c++ code I get the errors I've screenshot
// p12
#include <iostream>
#include <vector>
#include <string>
#include <map>
class Solution {
private:
std::vector<int> num = {1,4,5,9,10,40,50,90,100,400,500,900,1000};
std::vector<std::string> sym =...
For the first part, I have used a= 2, b = eps/2, c = eps/2 which I believe works and I have tested it in MATLAB however haven't had any luck reproducing the second part in MATLAB with any numbers. Any hints? Thanks
Hello! I am a bit confused about how to interpret symmetric error when doing error propagation. For example, if I have ##E = \frac{mv^2}{2}##, and I do error propagation I get ##\frac{dE}{E} = 2\frac{dv}{v}##. Which implies that if I have v being normally distributed, and hence having a...
I would like to know the opinions on the paper that I saw about Michelson-Morley experiment.
Michelson-Morley experiment was done in 1887 and had an impact on the future direction of physics. It is taught in schools as an experiment that proves the non-existence of the aether and proves the...
I know that least count is the smallest measurement that is possible with a measuring device. But I fail to understand the exact meaning of least count error. According to my textbook, the following is the definition of least count error.
"Least count error is the error associated with the...
Hello,
I need help with making sure I am using instrumentation error analysis correctly through an experiment in which I verify Ohm’s Law for a simple circuit. I do have a few questions below. I calculated and measured the error two different ways and did not get the same error by both methods...
Hi all. I'm working on my final project for a class. The assignment is to have a linked list of personal records, and then do some things with it. Right now I'm working on the linked list class "List.h". I've implemented a Person class "Person.h" as a composition of 3 subclasses "Address.h"...
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...
I just know that one assumption is that the specific heat capacity of water (as the surrounding) stays the same (or the change in its heat capacity is negligible). Please Help me with the rest.
Hi! I really need help with the following Matlab problem.
What does this code do? I need to comment what the important lines of this code do. Also the code contains several errors which i need to find. Here is the program:
clear all; close all; clc;
Maxi=50; tab=[1 :Maxi] ; tab(1)=0;
while...
Hi,
I was working on a predictive linear regression model and was hoping to obtain some bounds to represent the uncertainty present in the model.
Question:
I suppose this boils down into two separate components:
1. What is a good measure of uncertainty from a linear regression model? MSE, or...
This thread is to get more specifics and start discussion regarding two recent claims in other QM forum threads, in a separate thread to avoid clutter in other discussions:
@atyy, can you give specific quotes and references (chapter/page) in Ballentine that these quotes are talking about?
When an aircraft flies through things like updrafts, downdrafts, horizontal gusts and so on, does the velocity change produce Bernoulli effects that push the displayed altitude up or down wrt the correct altitude? If so, how much of a practical problem is it?
(By velocity change I mean the air...
Why do fractional errors have a different error value from subbing in the raw values?
e.g. 10 +- 1 divided by 10 +- 1
fractional error yields 20%
11/9 - 9/11 yields 40/99
In cases like these do we use the original values and attempt to find the maximum error distance or use fractional errors?
I'm using this user-defined module for an amateur coding project, and I am using 'Text' from the 'inquirer' module. When I am either inputting things, or whenever I am validating things, I always get some sort of error. These errors mainly result whenever I hit the back-space key on my...
Summary:: so I am trying to compile this program and i keep on getting "Unterminated character constant beginning at (1)" and "invalid character in name" at the months section. what do i have to change to fix it?
thanks
program Lab6
implicit none
character*9 month
integer monthNum, pos...
Hello! I made a linear fit, ##y=ax+b##, to some data points and I get the best parameters with their (1 sigma) errors: ##a\pm\delta a## and ##b\pm\delta b##. I want to plot this fit on top of my data points in such a way as to reflect the error on the parameters. The "main" fit is simply...
In the default installation of the gummi editor in Fedora, I find it difficult to locate LaTex errors. If I'm typing along and make a error in LaTex then the preview screen suddenly becomes a window saying no preview can be shown. I don't find the information in the "build tab" helpful. The...
What's the most common error in using computer interfaces?
The most common computer interface error that I make is clicking on the wrong "x" and unintentionally closing a window. I blame this on the fact that window managers use the same style of decoration for all windows, so all the "x"'s...
I attempted this a few times but keep getting the same wrong answer...
Converted the values:
q1 = 6.6E-6
q2 = 1.42E-6
q3 = -2.04E-6
d1 = .03m
d2 = .02m
Calculation for force on 1
F1 = - F12 + F13 = - (9E9*6.6E-6*1.42E-6 / .03^2) + (9E9*6.6E-6*2.04E-6 / .02^2)
(I used negative for F12 to...
I find most of the errors I make are related to arithmetic or using the wrong sign. (Note: This applies to mainly algebra and trigonometry for me.)
I've tried writing slower and neater, and have been structuring my operations linearly on the paper step by step.
Do any of you have some tried...
Hi,
I was reading about the soft errors. I read that the soft errors are the one that basically caused by alpha particles and even some time thermal issues (Too much heat in the machines). Although I search lot of mitigation techniques but I am curious that are these errors still exist and are...
For the sake of helping student to avoid confusions, I wonder if we can make a compilation of known errors made in standard and commonly used textbooks. Not talking about some random typos, but more when like the entire treatment of a subject is fundamentally flawed.
Hello I have some data points which have errors on both x and y coordinates. I want to fit a straight line to them but I am not sure how to take the error on x into account. Normally, when I have just the error on y, I want to minimize $$\sum\frac{(y_{pred}(x)-y_{measured}(x))^2}{\sigma_y^2}$$...
Hello! I am a bit confused about the systematic errors in experiments. For example, say that a mass scale was not calibrated and indicates 1g bigger all the time and I want to publish a paper in which to quote some measurements made with that scale. Let's assume that the value obtained, without...
Hello! I have some data (counts) with a Poisson error associated to it and I want to make a fit to the data. I am trying to weight the data inversely proportional to the errors, such that the data points with high errors are less important for the fit. However, using the the error on its own...
This started a couple of days ago. It is very sporadic, but comes and goes in waves.
I'll open a page such as facebook, physicsforums or any of a bunch of sites I visit regularly. I get this:
This site can’t be reached
www.facebook.com’s server IP address could not be found.
Try...
Hello! I have some data in which the dependent variable ##y## has, for each data point, an error bar associated with it ##\delta y##. The errors are almost identical for each datapoint, so doing a weighted fit in terms of the errors would not change the results significantly. How can I take the...
If I write ##f=\frac{uv}{u+v}## and then take differentials on both sides, I get ##\frac{df}{f}=\frac{du}{u}+\frac{dv}{v}+\frac{du+dv}{u+v}##, I get the fractional error as 0.03. (I have replaced the negative signs that come as a result of quotient rule with positive signs, since we are asked to...
I want to estimate the parameters and standard errors of the following ARMA/GARCH model:
##y_t=a+b y_{t−6}+cy_{t−8}+dϵ_{t−1}+ϵ_t##
##σ^2_t=ω+αϵ^2_{t−1}+βσ^2_{t−1}##The code I use is:
def main():
x0 = (0.01,0.01,0.01,0.01,0.01, 0.01, 0.01)
b = minimize(garch_loglike, x0, R_bel, bounds...
When subtracting measurements that each have a certain level of uncertainty, we can end up with huge levels of error if the two measurements are roughly equal in value. However, this problem doesn't appear when adding numbers.
Question: Is there a name for this type of error? Does anyone...
I have 2 independent samples (groups), each group contains 10 experimental values of variable T and their standard deviations (errors). I need to do intergroup statistical analysis, i.e. to elucidate whether there is significant difference between 2 groups in terms of variable T. I chose...
I am writing a document for my students about the proper use of ##\LaTeX##. There are some things that always scorch my eyes, like improper italics [##sin(x)##] or incorrect typography of units [##128kg##].
I wonder those of you who are sticklers for typography have other pet peeves of the...
[Note from mentor: this lacks the homework template because it was originally posted in a non-homework forum.]
I know this seems like a very dumb question but every other error I think of has been covered in precautions and the only errors I can think of are dumb ones. Help ! I had to plot the...
Homework Statement
Question is simple: what happens when ##DNL = -1 LSB## where DNL signifies differential nonlinearity and LSB stands for Least Significant Bit. It is also required to try and sketch such condition.
Homework Equations
Equation for differential nonlinearity: $$DNL(i) =...
A IRS auditor randomly selects 3 tax returns from 45 returns of which 15 contain errors. What is the probability that she selects none of those containing errors? Round to four decimal places.
Say I have say 10 measurements of an experimental observable e.g differential cross section with respect to rapidity , one measurement in each bin and corresponding statistical and systematic uncertainties given in % per bin.
Now, suppose I want the value of this dsigma/dy after correcting for...
Hello everyone, I'm trying to solve a BVP that seems to be very sensitive, for which I have to provide a starting guess and hope the program can fix it to find a solution. The program has been tested many times and it is very solid, the only problem should be that I can't find the right guess...
I am trying to switch to LaTeX after struggling with MS Word to the point of despair. Unfortunately, things aren't off to a great start. I want to build a resume and I found a template but when I try to compile it I get the following error even with another very simple "first LaTeX program" I...
Hi guys, apparently I've got both a linear and a subroutine programming error in the code below from lines 20-35? Could someone point me in the right direction. I think one might be the 'CALL wait' instruction, which should be 'CALL delay'? Not really sure as new to this, any help would be much...
Proposition(Zorn's Lemma): Let ##X\neq\emptyset## be of partial order with the property that ##\forall Y\subseteq X## such that ##Y## is of total-order then ##Y## has an upperbound, then ##X## contains a maximal element.
Proof:
Case 1: ##B\neq\emptyset## such that ##B##=##\{####b\in X##: ##b##...
Homework Statement
[/B]
I was reviewing this stuff and although I excelled at it once, I seem to forget some of it.
For example, please consider this:
Homework Equations
R_C=\frac {R_1R_2} {R_1+R_2} + R_3
Here's the correct formula for its error:
\Delta R_C=\frac {R_1R_2} {R_1+R_2} \left[...
Homework Statement
a) If you were using a hands –on activity to verify your predictions and use measurements to determine the wavelength of the laser being used, describe any safety precautions you would have to take and sources of error that you might encounter. Be sure to explain how you...
Hello!
I have a question that maybe has to do more with Mathematics, but if you do experimental physics you find it quite often.
Let's assume that we want to measure two quantities x and y that we know that they relate to each other linearly. So we have a set of data points xi and yi...