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.

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  1. P

    Refractive index experiment/finding error on graphs

    I'm writing a physics practical report on the refractive index of glass. We performed an experiment in which we measured the incident angle and the refractive angle of light entering a glass block. When plotting sin(ϴa) against sin(ϴg) with the y-intercept as 0 (to satisfy snell's law...
  2. C

    Solving for a variable inside the error function?

    i need to solve for a variable inside the error function on excel, is there an opposite function i can use to accomplish this? example: y = sqrt(x-t) -> x = t+y^2 except instead of a sqrt( ) I have erf( ) **this is not a math class so I don't have to get into breaking it down into the...
  3. P

    What is the cause of Verilog error message 10159 in my binary calculator code?

    I'm currently working on a project to create a binary calculator using verilog, which I will eventually program onto a DE2 FPGA board. I am trying to wrte my code but I keep getting the following error message. "Error (10159): Verilog HDL error at calculator.v(37): "Display" is not a task or...
  4. O

    Hex Meshing Error: Do I Need to Partition the Part?

    I am attempting to mesh this part using "hex" elements but I always receive an error. Am I supposed to partition the part? If so how do I do that? Thanks for you help P.S. I attached related documents to this post
  5. S

    Vandermonde Matrix and an Error Vector

    format long n = inputdlg('Please enter a series of numbers separated by spaces/commas: ') numbers = str2num(n{1}); X = 0 V = fliplr(vander(numbers)) r_size = size(V,2); c_size = size(V,1); B = 1+(r_size./numbers) X = B/V Here's what I have so far. I've been running the program with...
  6. H

    Possible error found in Keith Devlin's book The Math Gene Help?

    Possible error found in Keith Devlin's book "The Math Gene" Help? Homework Statement In the section "What is mathematics?" of Keith Devlin's book The Math Gene, he explains to the layman the purpose of abstractions. Devlin uses an example from group theory of symmetry to explain a point...
  7. M

    Percentage error and significant figure

    Homework Statement If a diameter of 15.5 +/- 0.1mm has been quoted and you need to turn this to a percentage error you get (0.1/15.5)*100 = 0.645... so you would quote this as a percentage error of 0.6% If it was 15.3 +/- 0.1mm and again you wanted percentage error (0.1/15.3)*100 =...
  8. M

    Error propagation question - when do we combine repeated measurements?

    Hi, say I measure something ten times and get x+d1x, x+dx2, ... where dx1, dx2.. are the measurement errors. Now, say I want to calculate something from these measurements according to: A = B(C(x)), Where A is what I want, and B and C are known functions. Which is statistically...
  9. Safinaz

    InsertFields Syntax Error in FeynArts

    Hi, I try to operate FeynArts, I installed by << FeynArts` Then I typed $ tops := CreateTopologies[1, 1 -> 2, ExcludeTopologies -> Internal]; $ InsertFields[tops, V[2] -> {F[4, {3}], -F[4, {3}]}, Model ->{SM}]; Here it gave an error InsertFields::syntax: The syntax of...
  10. A

    MATLAB Error Message while trying to Plot Magnification Factor

    Homework Statement I am trying to make a plot of the magnification factor of an underdamped vibrating system versus the frequency ratio using MATLAB. However, my MATLAB skills are very basic and I keep getting an error message. Basically I am trying to plot: MF=1/√((1-r^2)^2+(2ζr)^2)...
  11. G

    Size sample required to construct a 95% C.I. with margin of error

    N = 8 Mean = 2.10 stDev = 0.537 What size sample is required to construct a 95% confidence interval with a margin of error of 0.3? try n = 12, t(.975) with 11 deg. of freedom = 2.2001 so n = ( (.537* 2.2001) / (.3))^2 = 15.5 try n = 14, i get n = 14.95 n = 15, n = 14.74 Why is this a...
  12. M

    Fortran Fortran 90 (floating point error)

    Hello, I am dealing with the code below and i am receiving 'runtime error M6104:MATH floating point error:overflow'. i searched the error online and it is written the output values have high range than input values that i represent as input. I am using Microsoft Developer Studio and since my...
  13. MathematicalPhysicist

    Calculation of the error function.

    I have the next two signals: X(t) and G(t) and a random process Y(t)=G(t)X(t) where X(t) and G(t) are wide sense stationary with expectation values: E(X)=0, E(G)=1. Now, it's also given that ##G(t)=\cos(3t+\psi)## where ##\psi## is uniformly distributed on the interval ##(0,2\pi]## and is...
  14. D

    Deriving Error Equations for Half-Life Calculations

    Homework Statement How to derive an error equation: t1/ 2 = ln 2/λ= 0.693/λ. Confused, and don't even know where to start. 2. The attempt at a solution σ(t1/2)= σ(ln2)/(ln2) + σ(λ)/λ
  15. P

    Change In Gravitational Energy Percent Error

    Homework Statement There are two equations from which change in gravitaton potential energy of a system can be calculated. ΔEg = mgh and the other Eg = GmM/R The first equation is only correct if the gravitational force is constant over a change in height h. The second is always correct...
  16. T

    Reducing Error in Displaying vC(t) & vL(t): Tips for Lab 5 Procedure

    Lab 5 asks: what is the “inherent” error in our procedure for displaying both vC(t) & vL(t)? How would you go about reducing the effect of this error? If you look at figure 5.3 on page 41, you will see that the oscilloscope connects one end to node A and the other end to ground. Therefore...
  17. E

    Sources of error in thermal expansion

    I was just wondering what would be sources of error in calculating thermal expansion
  18. R

    Error message in lab course project using TEL-218DRV equipment

    I hope this is an acceptable location for this post. Does anyone have any experience trouble shooting or access to a help file for the Tel-X-Driver and TEL-218DRV equipment? I have included a copy of my correspondence with the company explaining the situation below. Homework Statement My...
  19. B

    Error propagation in an average of two values

    I'm writing up an experiment I did for a lab course and I am calculating the error in quantity V. I have two runs and have ended up with a value of V for each one, as well as an error. Ie, I have V = 0.1145±0.0136 for Run 1 V= 0.1146± 0.0134 for Run 2 I got my errors through some tedious...
  20. D

    Matlab error message, help please

    I get this error message Subscript indices must either be real positive integers or logicals. Error in doubleODE (line 14) dYdt(2) = l1*(m1 + m2)*Y(4) - l2*m2*Y(3)*cos(Y(1) - Y(2))/... I am having trouble working out what is causing the problem. Any advice? Thanks
  21. B

    Probability of Error Occurring in Message

    We are given a message of length n (it has n characters). There is a 0.1 probability for each character to be corrupted. What is the probability that m characters are corrupted? I honestly have no idea how to solve this. Suppose you have 7 characters and you want to know the probability...
  22. P

    Calculating Error in Horizontal Velocity for Bouncing Ball Experiment

    Homework Statement I slide a ball off of a ramp (the ramp is on a table) and the ball hits the ground and bounces horizontally and vertical. I know that horizontal velocity = horizontal distance*sqrt(gravity/2*height) or d*sqrt(g/2h) I want to know the equation for calculation error. The...
  23. R

    Fortran Why Is My FORTRAN If/Else Statement Not Working Correctly?

    I am not able to get what's wrong in below. IF ( temp < 97.5 ) THEN WRITE (*, *) NTemperature below normalN ELSE IF ( temp > 97.5) THEN WRITE (*, *) NTemperature normalN ELSE IF ( temp > 99.5) THEN WRITE (*, *) NTemperature slightly highN ELSE IF ( temp > 103.0) THEN WRITE (*, *)...
  24. W

    Error equation for the balmer series

    Homework Statement I have to find the error in λ determined by the Bohr model/Balmer series. I am a bit confused with this so I'd like someone to double check my work. I don't know the exact name of this method but basically all you do is take the differential of all the values which have an...
  25. S

    Steady State Error Calculation to Input Step and Ramp Input

    Hi all, I am getting confused about how to calculate steady state error in a system. My particular transfer function is: G(s)= 4.992/(s^2+3s-1) Firstly, with an input step am I right in saying that the Steady State error will always be zero? If so can someone explain the reason behind this...
  26. T

    Finding maximum percentage error using differentials?

    Homework Statement Here is the question along with the solution: Can anyone explain why the terms I circled in red are different? For the first term there is a negative sign but then the second term does not? Why did it disappear?
  27. J

    Java This error (Java) is confusing me

    It's saying I don't have an 'if' statement for my 'else if' statement, but I do. You can see clearly from this picture that I do.
  28. S

    MHB Use differentials to estimate the error

    One side of a right triangle is known to be 20 cm long and the opposite angle is measured as 30°, with a possible error of ±1°. (a) Use differentials to estimate the error in computing the length of the hypotenuse. (Round your answer to two decimal places.) ±...cm(b) What is the percentage...
  29. S

    Mean squared error (why mean?)

    Hi I found this equation in a machine learning book: "we want to minimize the mean squared error:" $E= \frac{1}{2} \sum_{n=1}^N (y-t)^2$ what I do not understand is the \frac{1}{2} , if it is a mean it should be \frac{1}{N}, why are they restricting to 2? In the text there is no reference to y...
  30. O

    Explain how do we get standard error.

    Homework Statement I know that standard error is to calculate how the sample deviate from the population. But standard deviation divide √n ,then will get it. And I don't understand why there is a T/n from the picture I uploaded. Please help Homework Equations Standard error x sqrt(n)...
  31. S

    Error Rate and Its Role in Significance

    I am trying to understand the relationship between p-values and Type II error rate. Type II error occurs when there is failure to reject the null when it is false. As an example, suppose that I find that my results are not significant. In this case, the p-value is increased, or higher (in...
  32. J

    Java [Java] Can't figure out this Illegal start of expression error

    [Java] Can't figure out this "Illegal start of expression" error From my Java code: while (info.substring(j, j)) != " ") { name += info.substring(j, j); j++; } gives an "illegal start of expression" error
  33. C

    How to find error between non-linear plot and data points?

    Is there a formal way to measure the error between some arbitrary points and a non-linear curve in order to minimize it?
  34. R

    Error propogation in trig functions

    Homework Statement I have to use this in my calculation \theta=\tan^{-1}\left(\frac{19 \pm 1}{47 \pm 1}\right) where both are in mm. How would I get this into \theta\pm \text{error}? Homework Equations shown above The Attempt at a Solution looked through my lab manual, it wasn't...
  35. S

    How Do You Calculate the Mean and Its Standard Deviation in Error Analysis?

    I'm doing a report on a set of lab data and am supposed to find the mean and mean's standard deviation \bar{x} + \sigma_{\bar{x}} The mean is given by \displaystyle{ \bar{x} = \sum_{i=1}^{N} w_{i} x_{i} } Where \displaystyle{ w_{i} = \left( \frac{\sigma}{\sigma_{i}} \right)^2...
  36. Saxby

    Fortran Fortran90 problem, runtime error

    Hello, I've been playing around with some code (as shown below) and for some reason everytime i run this code I am told: At line 11 of file tester.f90 Fortran runtime error: End of file I'm not really sure what's causing it, is it the position of my Open file? Any help would be much...
  37. O

    Fortran Fortran, File Read Error( Tried to read past )

    Fortran, File Read Error[Resolved itself, fixed] Basically I'm writing a simple fortran program to read in a data file formatted as shown below and then calculate the line of best fit for the given data points. N x1 y2 x2 y2 . . . . . . xn yn Where N is the...
  38. B

    Where is the error in this argument

    It is possible to do this and it is correct: \log \left[\sqrt{i}\right] = \log\left\{\exp\left[\frac{i}{2}\left(\frac{\pi}{2}+2\pi n\right)\right]\right\} = \frac{i}{2}\left(\frac{\pi}{2} + 2\pi n\right) = i\left(\frac{\pi}{4} + \pi n\right) But: \log \left[i^2 \right] =...
  39. J

    Estimating the error of an iterative sequence

    Homework Statement This isn't quite homework (though it's close), but I'm working on a quantum circuit and wish to implement an iterative method to find the square root of a number using elementary arithmetic operations (and without reciprocals). I've gotten most of it down, but the error...
  40. S

    Finding Error in Alternating Series

    [b]The problem statement says to find out if the next series converge, and if it does to calculate the sum with an error ε< 10^{-3} The serie is this one \sum^{\infty}_{n=1} (-1)^nne^{-n} First of all the serie converges because of Leibniz Criterion but the i did the series of |an| I did it...
  41. C

    Why Are My Excel Error Bars Only Horizontal?

    I have a graph which I would like to add Y error bars to. When I click to add the error bars, it only allows me to add horizontal bars. This is very strange because the other graph I have, it allowed me to insert vertical bars. Basically when I click on exactly the same menu to insert error...
  42. O

    RMS error in volume of a cylinder

    Homework Statement The length and radius of a perfect cylinder are measured with an RMS error of 1%. The RMS error of the inferred volume of the cylinder is.. ?Homework Equations V=∏r2h Hence dV/V=2dr/r+dh/h The Attempt at a Solution I took dr/r and dh/h as 1%. So got the final answer as...
  43. M

    Fortran How can I fix a Fortran compiling error?

    I Just finished installing gcc and SciTE . when i try to run a basic code ..the following error is returned(refer attached file) many thanks PS:I have saved fortarn.properties file in the installation folder of scyntilla
  44. E

    Understanding the 'ERR: Nonreal Ans' Error with Psi and Phi

    I just had a question involving both psi and phi. I know that: Ψ= (1-√5)/2 = -0.618033989... Φ= (1+√5)/2 = 1.618033989... And out of boredom, I decided to put into my calculator: (Φ^Ψ) = 0.7427429446... But my question rose from there: What happens if you do (Ψ^Φ)? I plugged it in and...
  45. W

    Understanding the Error of Taylor Polynomials in Approximating Functions

    the error of a taylor series of order(I think that's the right word) n is given by \frac{f^{n+1} (s)}{n!} (x-a)^n I think this is right. The error in a linear approximation would simply be \frac{f''(s)}{2} (x-a)^2 My question is what is s and how do I find it. Use linear...
  46. S

    MATLAB MATLAB - Find the error on polynomial fit parameters of experimental data

    See attached PDF for details: How do I calculate errors on the fit parameters, p?
  47. M

    Fortran Error 112 /undef when running fortran code

    Hi, I am a new Fortran User. I have a problem when I run my code (not errors during building), in fact the code is stopped in the last line and this message appears "Error 112, Reference to undefined variable, array elements or function result" ... write(number,100)k1 open...
  48. H

    C/C++ [C++] error: File cannot be found

    So I just started teaching myself C++ using visual studio 2010. I started with a nice easy program. First thing I did was created a new project called "Tutorial." Under source files I right clicked and selected add -> new item, I named it Introduction.cpp. I created this: #include...
  49. M

    Manchester Encoding Probability of Error

    Greetings, I am studying Analog & Digital Communications in one of my lectures and I'm stuck with a subject. I would be much pleased if someone is willing to help me on the subject below; Probability of error of a digital signal sent by using non return to zero encoding is easy to find...
  50. D

    Comp Sci Help with FORTRAN error message

    Homework Statement I get the follwing error message in the FORTRAN program I am trying to code. P(i)=(1/(sigma*sqrt(2*Pi)))*e^(-(x-xbar)^2/(2*sigma^2)) ----------------------------1 Error: Invalid character in name at (1) I assume this means there is something it doesn't like about...
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