What is Error: Definition and 999 Discussions

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.

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  1. 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...
  2. 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...
  3. 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...
  4. 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...
  5. 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...
  6. 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...
  7. 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
  8. 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|| =...
  9. 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...
  10. 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...
  11. 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...
  12. 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...
  13. 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...
  14. 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...
  15. 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...
  16. 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...
  17. BiGyElLoWhAt

    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...
  18. 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...
  19. 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...
  20. 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?
  21. 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...
  22. 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...
  23. A

    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...
  24. 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...
  25. 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...
  26. 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 ...
  27. 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...
  28. 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...
  29. 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...
  30. 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...
  31. 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...
  32. 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...
  33. 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...
  34. 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...
  35. 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...
  36. 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...
  37. 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...
  38. 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...
  39. 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...
  40. 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...
  41. joneall

    Relativity Is There an Error in Hartle's Fig. 7.11 Caption Regarding Normals and Tangents?

    A question concerning FIg. 7.11 on page 173. It seems to me, in light of what is said on the preceding page about null surfaces, that he has interchanged "normal" and "tangent" in the third and fourth sentences of the figure caption. I would say: "The tangent to the surface l lies in the...
  42. J

    I in deciding what my error bars should be

    So, we did an experiment to find the dissolved oxygen concentration in % over time in a stirred tank reactor at 2 different flow rates and at 3 different agitator speeds. We did not do any repeat measurements, it was just one reading per condition. Now I am confused what sort of error bars I...
  43. kelvin490

    Fortran Input/Output error with error code -5

    I got a problem running my FORTRAN program in high performance computer cluster. It runs well in my PC but I want to have mass production of data with different initial conditions so I put it in a cluster node with eight cores, simulate eight sets of data. The program can run without problem...
  44. H

    Error in Srednicki renormalization?

    On page 164-165 of srednicki's printed version (chapter 27) on other renormalization schemes, he arrives at the equation $$m_{ph}^{2} = m^2 \left [1 \left ( +\frac{5}{12}\alpha(ln \frac{\mu^2}{m^2}) +c' \right ) + O(\alpha^2)\right]$$ But after taking a log and dividing by 2 he arrives at...
  45. 24forChromium

    How to address experimental error in conclusion

    I am writing an essay which includes the experimental "verification" of a theory. As it turns out, the theory was able to predict a certain variable F's direction of change (i.e. increase or decrease across two data points) "correctly" for 90% of the time, and predicts the value of F at each...
  46. A

    Error in My Code: Undefined Symbols for x86_64

    I have received this error : Undefined symbols for architecture x86_64: "start", referenced from: -u command line option (maybe you meant: __gfortrani_library_start) ld: symbol(s) not found for architecture x86_64 collect2: error: ld returned 1 exit status what is this mean?? the code is...
  47. P

    What Is the Error in Counting Rate Per Second for Gamma Photons?

    Homework Statement A detector is used to count the number of gamma photons emitted by a radioactive source. If the number of counts recorded in exactly 20 seconds is 10000, the error in counting rate per second is (a) 5.0 (b) 22.4 (c) 44.7 (d) 220.0 Homework EquationsThe Attempt at a Solution...
  48. Bera Icli

    Stiffness/Residual Vector Error - NaN/Inf findings

    Hi, I am especially writing this, because there is no specific explanation I found online. I checked the BCs and other variables, but could not find any mistakes. I am working on a semiconductor device that is basically n-doped homogeneously, has sizes 50um-15nm, and with a drain voltage 1V...
  49. J

    Error while accessing board through TTL

    I am trying to access a console with my TTL (cp2102 ) but I am getting following error. What could be wrong? I am trying J4 point for TTL. I am connecting ground to ground, Rx to TX and TX to RX. Only with this combination I am getting the log as posted below. 3.3V is not needed in my case as...
  50. GiantSheeps

    Sources of Error in Flame Test Lab

    Homework Statement In a flame test lab, where different unknown substances are heated and the identity of the substance is determined by the color emitted, what can be some sources of error? Homework Equations n/a The Attempt at a Solution I need three sources of error, and so far I have...
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