Error Definition and 998 Threads

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.

View More On Wikipedia.org
Recent contents Top users
  1. H

    Error in inner product of vectors and index

    Hello I found a bug in my code and can't figuring out the error. I tried debugging by showing the output of each variable step by step but I can't find my error. Here is what I have and what I want to do: I have a matrix A: 0000 0101 1010 1111 And I have a matrix B: 10000 21000 30100 41100...
  2. C

    MHB Random Number Generation Avoiding Human Error in the Keyboard

    Hi All Im hoping I am in the right area to ask this?!? Im looking for someones help. Is there a standard methodology or known equation for generating a random alpha numeric serial or incremental, which does not allow two characters to be used in sequence to each other which are near each other...
  3. CynicusRex

    I Poisson process approximation error

    X = # of cars that pass in one hour E(X) = λ = n * p λ cars/1hour = 60min/hour * (λ/60) cars/min In this old video (5:09) on poisson process Sal asks: "What if more than one car passes in a minute?" "We call it a success if one car passes in one minute, but even if 5 cars pass, it counts as 1...
  4. S

    I Why is the standard deviation the error on the singular meas

    I'm a beginner with the study in data analysis in Physics. I'm trying to understand the meaning, in the field of experimental Physics, of the standard deviation ##\sigma## of a series of data. There is one fundamental thing about ##\sigma## that I read but I could not understand. >In a series...
  5. BiGyElLoWhAt

    Python Debugging the Swarzchild Metric - ValueError

    I'm messing around with the swarzchild metric, and I keep getting errors. First, it was a memory, which I could have guessed, 10000x10000 array, so I lowered it to 1000x1000 and it moves past that point, now. However, this is where I'm getting my error: Gravity = zeros([1000,1000]) while i <...
  6. A

    MHB Margin of error and point estimate together

    Hey all I have one last question for you. I just need clarification on point estimate and margin of error as I have to find both in a problem. Let's say the endpoints are 5.9 and 8.1. When I do a margin of error problem, I subtract the mean of 7 from 8.1 right? When I do point estimate do I add...
  7. G

    MHB How to find the upper bound of an error by Taylor polynomial approximation

    I'm struggling about finding a way to find the upper bound of the error of Taylor polynomial approximation. I will explain better using a solved example I found... > $f: ]-3;+\infty[ \rightarrow \mathbb{R} $ $f(x)=ln(x+3) +1 $ >Find the upper bound of the error approximating the function in...
  8. K

    Calculating the error in <x^2> from the error in <x> (Molecular Dynamics)

    Hi, does anyone know of an easy way to calculate the error in <x^2> from the error in <x>? I am running a molecular dynamics simulation and trying to work out the error in the fluctuation of kinetic energy <dEk> = <3/2NT^2> - <3/2NT>^2 from the error in <T>. Thanks in advance
  9. Tallus Bryne

    ANSYS Fluent error reading .cas file

    This is my first time using ansys Fluent, and I am trying to follow this tutorial for modeling a heat exchanger under various conditions. I have been provided with a "Case 1 Mesh" file of the extension type .cas which is to be used in our simulation involving several or one heating element(s)...
  10. Erenjaeger

    Please help, stuck -- Standard error in speed of sound wave....

    https://fbcdn-sphotos-a-a.akamaihd.net/hphotos-ak-xfa1/v/t34.0-12/13100972_1004336679646107_71786442_n.png?oh=c0e0ad9cf30125d301d2069c6402b621&oe=57222F24&__gda__=1461854936_dad2ac5d3bd3a844b9428cd47c7dc733 Not sure if this counts as "advanced physics homework" but can someone please help me...
  11. rolotomassi

    MATLAB Why am I getting a 'Matrix is singular to working precision' error in Matlab?

    Here is a link the code which I am trying to modify. It is the radial average of a matrix function. http://uk.mathworks.com/matlabcentral/fileexchange/46468-radialavg-zip/content/radialavg.m I want to restrict the function to only look within certain angles, e.g. 15 degrees either side of the...
  12. Shawndude

    Analysing 2 Material Cylinder w/ Internal Pressure 100 Units

    I am trying to analyse a two material cylinder glued together .The cylinder is subjected to internal pressure of 100 units. The problem i am facing is that the radial stress at the inner radius (where the internal pressure is applied) is not equal to the internal pressure.I.E. if the internal...
  13. whatphysics

    Using differentials to estimate the maximum possible error

    Homework Statement Consider a closed rectangular box with a square base of side 3cm and height 5cm. If the side is measured with an error at most 0.02cm and the height is measured with an error at most 0.01cm, use differentials to estimate the maximum possible error in computing the volume of...
  14. E

    Mathematica Solving Mathematica Error: NIntegrate::ncvb

    Hello, I have the following code in Mathematica, and it gives the following error: NIntegrate::ncvb: NIntegrate failed to converge to prescribed accuracy after 12 recursive bisections in x near {x} = {0.000156769}. NIntegrate obtained 0.21447008480474927` and 5.637666621985554`*^-13 for the...
  15. S

    I Boltzmann distribution: isothermal atmosphere error?

    There is a well-known analysis of the distribution of particles by height in an isothermal atmosphere. It states that the probability of finding a particle at height ##h## is ##p(h) \propto e^{-\beta mgh}##, and then goes on to state that the number of particles at height ##h## is ##n(h) \propto...
  16. S

    Electric Field along bisector of charged line (w/error)

    Homework Statement You wish to determine the electric field magnitude along the perpendicular bisector of a 230-mm line along which35 nC of charge is distributed uniformly. You want to get by with a minimal amount of work, so you need to know when it is sufficient to approximate the line of...
  17. B

    I How to Estimate Uncertainty for a Physical Quantity with Dependent Variables?

    I have a physical quantity A defined as ##A=(74.5 B^2*(M+N))^{1/3}## where B, M, N and relative uncertainties are given. And M and N are dependent on B. Could you show me how to calculate and estimation for the uncertainty on A? Thanks a lot
  18. Y

    Linear Algebra - Gram Schmidt & Normalization - Error in Sol

    Homework Statement So I think I found an error in the solution were it attempts to find q_2^ I'm asked find the orthornomal basis for the column space of matrix A. Homework EquationsThe Attempt at a Solution [/B] My question is in what it puts for q_2^ A_2 = [4/3 4/3 -2/3]^T ||A_2|| =...
  19. Holden Kenne

    B Understanding Newton's Laws of Motion: Exploring Errors and Contradictions

    Hi, I'm a frehshman in High school writing a paper about Isaac Newton. One of my paragraphs is about the laws of motion. I came across a tidbit of information - there are instances in which Newton's laws are not correct. One example I found was that, at speeds approaching that of light, an...
  20. Amine_prince

    B Error in Vector Addition: U & V Perpendicular

    i have two unitary vectors in space U and V , U and V are perpendicular . W is a vector that verifies W ^ V = U - W . the following resolution is incorrect , i wan't to understand why : we use (o,U,V,(U^V)) . components of U (1,0,0) , V(0,1,0) , W(a,b,c) where a , b and c are real...
  21. skate_nerd

    How to make thick line error bar for plot

    Disclaimer: I'm not exactly sure that this topic would belong in this thread but I don't think it would fit better anywhere else. I'm working on writing a paper for my grad research project and my PI wants me to model the plots after another paper that our lab published in the past, but I'm...
  22. D

    I think my AP review book has an error. Can someone check?

    Homework Statement An object of mass m is allowed to slide down a frictionless ramp of angle θ and its speed at the bottom is recorded as v. If this same process was followed on a planet with twice the gravitational acceleration as Earth, what would be its final speed? Homework Equations The...
  23. RoboNerd

    Titration error affecting the PH of the endpoint

    Homework Statement Hi everyone. 1) If I perform a titration with a buret not rinsed in the titrant, then how will the pH of the endpoint be affected? 2) Also, if the volumetric pipet used to measure the analyte is not rinsed with the analyte, how will that affect the pH of the endpoint...
  24. A

    Calculation of permissible error in physical quantity

    Homework Statement I have doubt in calculating the permissible error. It goes as follows Measure of two quantities along with the precision of respective measuring instrument is A = 25.0 ± 0.5 m/s, B = 0.10 ± 0.01 s. A physical quantity C is calculated as C = A × B. What will be the value of...
  25. T

    I Error propagation of exponentials

    I am just wondering why there is a discrepancy between two different methods for error propagation. For example, if you have ## Q = (a)(b)(c) ## then the relative error in Q is simply the square root of the sum of the squares of each of the terms being multiplied together, correct? But what if...
  26. A

    Calculation of permissible error in physical quantity

    Homework Statement I have doubt in calculating the permissible error. It goes as follows Measure of two quantities along with the precision of respective measuring instrument is A = 25.0 ± 0.5 m/s, B = 0.10 ± 0.01 s. A physical quantity C is calculated as C = A × B. What will be the value of C...
  27. BiGyElLoWhAt

    Python Solve Lambda Error in Python Homework

    Homework Statement Somewhat irrelevant, but we need to simulate the redshift for a star system. Pretty open ended. Single star, binary, whatever. The problem is this: TypeError: <lambda>() takes at most 1 argument (5 given) And upon searching, most people who get this error have a function that...
  28. Jess Karakov

    Trapezoidal Rule: Maximum error in approximation?

    Homework Statement Suppose that T4 is used to approximate the ∫ from 0 to 3 of f(x)dx, where -2 ≤ f ''(x) ≤ 1 for all x. What is the maximum error in the approximation? Homework Equations |ET|≤ (K(b-a)^3)/(12n^2) The Attempt at a Solution So I know how to find the error of the trapezoidal...
  29. N

    Maximum Error Using Differentials

    Homework Statement 2 adjacent sides of a parallelogram measure 15ft and 10ft w/ max errors of ±0.1ft angle is 45° w/ max error of ±0.5° What is the maximum error in the calculated value of the area or the parallelogram? Homework Equations A = area = xysinθThe Attempt at a Solution x = 15ft...
  30. E

    Mathematica Fixing Error in Tag Times: Get Quick Solutions!

    Hey, I'm unsure why the following returns an error: Any ideas on how to fix this?
  31. T

    How does error propagate in a complex equation involving averages and variances?

    Homework Statement Hello, I have the following operation that I want to perform: f=\frac{\bar{X}}{100-\sum \bar{Y}_j}*K \bar{X} and \bar{Y} are averages with variances S_{X}^2 and S_{Y_j}^2 and K is a constant. How will the error propagate? Homework Equations According to...
  32. Steve619

    Understanding Absolute Error in Machine Measurements: The 1.3% Mystery Unveiled

    In writing up on errors and knowing the error of the machine used (as told by the technician) as being 1.3% where I have a table of theoretical and measured values, The absolute error the difference between the theoretical and measured value, but where does the 1.3% error come into play? And...
  33. A

    Python Monte Carlo error calculation PYTHON

    I am using the monte carlo method to calculate the integral of cos^2(x). This is done using N random numbers. In my case I am doing it for 10^i random numbers when i ranges from 1-6. I want to calculate the error on the integral for each value of i used. I know for each value of N I want to...
  34. A

    Comp Sci C++ Error Checking (Simple program)

    Homework Statement I am writing a program that will calculate the average and standard deviation given data by the user. The data is entered into a vector. The size of the vector is also determined by the user. When the user enters the size of their vector, they need to enter a positive...
  35. N

    Using Partial Derivatives to estimate error

    Homework Statement [/B] The area of a triangle is (1/2)absin(c) where a and b are the lengths of the two sides of the triangle and c is the angle between. In surveying some land, a, b, and c are measured to be 150ft, 200ft, and 60 degrees. By how much could your area calculation be in error if...
  36. jk22

    Error : what is n in quantum mechanics

    Suppose I have an operator A. Its average is <A> and the standard deviation $$\sigma=\sqrt {<A^2>-<A>^2} $$. I now want the standard error which is $$\sigma/\sqrt {n} $$. I wondered what n is in quantum mechanics ? The wsvefunction is supposed to describe a single particle so it should be 1 ...
  37. E

    Determining an error due to non point like detector

    Homework Statement Recently I have conducted an experiment using a gamma source (22Na) and a scintillation detector (NaI), at the start of the experiment one of the desired outcomes was to see that the intensity of the source fell off as 1/r^2. Seeing as the detector is not point like (I am...
  38. A

    PSPICE Error when trying to run simulation

    Hi, so I built this circuit I'm trying to run a parametric sweep of the voltage source. I'm running it from 0V to 30V with a 0.1V interval So I put up the simulation settings that I wanted: and I ended up getting this error: I tried it on different computers as well and I still got the same...
  39. B

    How to code the expression with least roundoff error

    The expression to code is: (z complex, m some positive integer) z^m ( ln(z/(z-1)) - sum( 1/(k z^k), {k=1,m} ) ) The way I code is (in fortran) (in case z<2) Z_1=1.0_q/Z ZV1=LOG(Z/(Z-1)) ZK=1.0_q DO K=1,M; ZK=ZK*Z_1 ZV1=ZV1-ZK/K ENDDO ZV1=ZV1/ZK But it gives quite big error...
  40. S

    Error in summation of spectral components

    HI everyone, Imagine we are sampling of a gaussian signal along time and need to know the power/variance associated with the first N spectral components. So we take our favorite fft algorithm to get the PSD. The error associated with a given estimated spectral component f(w) (w is the...
  41. GiantSheeps

    Reasons for error in percentage of oxygen in KClO3 lab

    Homework Statement I did this lab on percentage of oxygen in potassium chlorate and I got a percent error of about 30%. I now need to find three reasons for error, and human error does not count. I think one could be that the masses used in calculating the theoretical percentage of oxygen were...
  42. A

    Can someone explain the Taylor's Theorem error bound?

    Homework Statement So I've read a lot about this but still can't figure what's going on. I understand that to find the error of approximation all we have to do is: |E(x)| = |f(x)-Tn(x)| But what about M*(xn+1/(n+1)!) What's the point of this? and why does it have to be greater than or equal...
  43. B

    Error propagation and significant digits

    Moderator's note: Thread moved to homework section. Thus no template. I have an exercise in which I have to calculate the Area from the following measurements: L = 22.1 ± 0.1 cm W = 7.3 ± 0.1 cm Of course, A = W * L = 161.33 but since I have a measurement with just 2 significant digits the...
  44. J

    Run-time error M6201: math -log: DOMAIN error

    Hi all, I am facing the problem while executing my fortran (77) program. please help me how to fix it. As I understood, the error means that the domain of log function has included zero values or negative values...But I could not understand...In my case... there are no zero or negative...
  45. Devraj Dutt

    ANSYS Maxwell Optimetrics Error Handling

    A common problem with optimization of machines is that occasionally, some of the variable combinations will not be geometrically feasible. For example, if magnet angle is being parameterized in an IPMSM, it might be that at some point, the magnet skews so much that it juts out of the rotor...
  46. gabforse

    Fortran Why Does My Fortran Code Give an Unclassifiable Statement Error?

    Hey so I'm getting the error message: Euler_Method.f90:43.1: fun=(c)(1-c)/(d+2) 1 Error: Unclassifiable statement at (1) And here is my code: PROGRAM Euler_Method !------------------------------------------------------------------- ! The purpose of this program is to read in endpoints...
  47. T

    How do I calculate the error of my data?

    Hello.I have 3 repitions of an experiment. The data consists of mass flow rates vs. time. What I want to do is to calculate the mass vs. time, i.e. integrating my data. I consider the resolution for each measurement to be exactly 3 minutes. To calculate the area I use the trapetzoid rule, i.e...
  48. RJLiberator

    Static measurement of Spring constant with error value

    Homework Statement It's been a little while since I did one of these. My question is: We have to use http://phet.colorado.edu/sims/mass-spring-lab/mass-spring-lab_en.html to find the measurement of k, the spring factor using two different methods. For the method I am looking at, is the static...
  49. Alpha123

    Why the experimental error for CaOH is larger than MgO?

    Homework Statement I did a lab on the experimental application of Hess's law. There were two experiments where a substance in a solution was dissolved and the temperatures were recorded. Then the standard heat of formation for the substance was calculated. The first experiment used MgO and HCL...
  50. SpiffyPhysics

    Is this an error in the text? (Gas Turbine Combustion Chamber)

    Hello I am teaching physical science at an online school, and came across this issue in the textbook - I'm looking to double check with more knowledgeable people before I bring it up and potentially make a fool of myself. In one chapter of the physical science text it discusses various...
Back
Top