Error Definition and 998 Threads

So I'm in the Navy. I work on an aircraft carrier that just went into drydock. The drydock has a large trapezoid door keeping the water out on one side. Our captain wants to know how much force is being held back on that door. I found the dimensions of it and calculated it, but now I'm having...

Sorry if I'm in the wrong subforum. This is a rather simple and straightforward question, I hope. I'm doing a measurement that requires me to do a linear regression on data points to get a value of the slope. The slope is the value of the actual property that I am measuring. Assuming...

Here is the question: I have posted a link there to this topic so the OP can see my work.

Hi all, I'm trying to calculate the M.A.P.E. using the accuracy() function in SDMtools. I have an output of 10.69. I'm not sure if this is 10.69% or 1069% as previously in a different model I had gotten an output of 0.34. If anyone is familiar with this, I would appreciate any help...

I am calculating the dipole moment of a metal sphere in a uniform electric field E_0 in z-direction. From here I know that the charge density [look at page 15][1] [URL="[PLAIN]http://www.phy.iitb.ac.in/~dkg/PH-102/conductors.pdf"]http://www.phy.iitb.ac.in/~dkg/PH-102/conductors.pdf[/PLAIN]...

Dear, Can someone tell me with certainty if the truncation error of the general ADI method is of seconder order in time and space?

Hi Forum users I have a velocity autocorrelation code which was made to read a three component velocity vectors and I have modified to read a 9 component stress tensor data. I can compile it successfully but when I try to run it and compute a stress correlation function I get an error: i.e...

Suppose we know the perturbation series E = E(\epsilon) = E_0 + \epsilon E_1 + \epsilon^2 E_2 + \ldots converges, where E_0 is a discrete eigenvalue of H_0 and we are considering a Hamiltonian H = H_0 + \epsilon H_1. Does this mean that we know E - E_0 = O(\epsilon) as...

Hello, I had started an earlier thread on porting this same program to linux. In that thread I had asked about padding (align) issues. It may turn out that the padding messages may only be warnings and I have shelved that problem. A more critical issue is the one error on ambiguous use of...

https://www.khanacademy.org/math/probability/regression/regression-correlation/v/r-squared-or-coefficient-of-determination Homework Statement So, when determining how effectively a best-fit line describes the variance of a given set of measured data, the Coefficient of Determination is the...

Suppose we have x plates of wood of thickness (0.0150 \pm 0.0002) \text{ m} and we wish to stack them into a pile of height (1.000 \pm 0.001) \text{ m}. The number of plates x required is then x = \dfrac {1.000 \pm 0.001}{0.0150 \pm 0.0002} \, . How many plates will certainly fit in the...

My book says: The bit I don't get is Why? Apply this logic to one of the numbers at random for arguments sake, let's say the first number .234673, it couldn't be .2346735-.2346739 or else it would have been rounded to .234674. It's true value (if it's greater) has to lie somewhere between...

Homework Statement From Mathematical Statistics and Data Analysis 3ed, Rice 1.8 #61 Suppose chips are tested and the probability they are detected if defective is 0.95, and the probability they are declared sound if they are sound is 0.97. If 0.005 of the chips are faulty. What is the...

Hi, I am trying to understand how I find the error in linear regression, and what to do with it. I am using linear regression to predict the time of execution based on the size of the input and the number of tasks used in the computer to get the result. 1 - In a linear regression, I calculate...

Homework Statement I'm working with a particularly malicious mass model function given as: λ^n*exp(-x^2)*(λ+x)^-n, λ=constant, n=constant (1.8 for those who care) The first round of integration by parts using u=(λ+x)^-n, du=-n(λ+x)^(-n-1)dx dv=exp(-x^2), v=sqrt(pi)/2*erf(x) Gives me...

Hi! I'm trying to write a function that will integrate a user given function. I am having trouble with reading the function. Here is a section of my code: [FONT="Courier New"]function f(x) implicit none real :: x,f,p print *,'Type a probability density function' read *, p !It doesn't...

What is wrong?? Hi, I want to know where is the mistake in the statement below (I really don't know what is wrong, but it is obviously wrong) \frac{\partial ^{2}x}{\partial t^{2}} = \frac{\partial ^{2}x}{\partial x^{2}} (\frac{\partial x}{\partial t} )^{2} But...

Getting an "unclassifiable statement" error in Fortran 95 I am trying to integrate the function x from 0 to 1. Here is my code: [FONT="Courier New"]program myownmonte !This program will integrate the function x from 0 to 1 implicit none real :: ans0,y,f,x,xmax integer ...

I have a book called REA 's problem solvers: Differential Equations Year 2004 and the problem 12-14 on page 244 might have problems with it and I want to ask to see if anyone else thinks so. The problem is basically Newton's cooling where they ask to find T - T_o = (T_i - T_o) e^(-kt)...

Array `cm' at (^) is too large to handle I get this error/warning when compiling with the Force 2.0 G77 compiler. However, I do not get this with my MinGw G77. This is the first program I have found that causes this error with Force 2.0, but I would like to fix it. Any ideas why it would...

Homework Statement You measure 50V with a voltmeter, which has 300V as the max. input voltage. What will be the relative error (h%) of the measurement? Homework Equations The Attempt at a Solution hi i divided 50v / 300 V and get = 1,66 and divided it by 100 to get relative error...

I've recently done an experiment where I've obtained the strain of a channel section beam in bending. I used a strain gauge to get the strain from the midspan and also used dial gauges to get the deflections of the beam under different loading conditions. Along with the readings I've...

Error Analysis/Significant Figure help please! Hi Physics Forums, I have an assignment due very soon and I have completed everything, bar error analysis. I have been told that we need to calculate relative and absolute errors or something along those lines and I have NO IDEA what I am doing...

Homework Statement The question is: The Earth formed 4.57 x 10^9 years ago. What is this time in seconds? The answer the textbook is giving is 1.44x10^17 seconds. The answer I keep getting is 1.44x10^15 seconds. Is the textbook wrong or am i wrong?

Hello,everyone.Lastly,I use MCNP to claculate the dose distribution of CT phantom,but when I run my code,I get a message that says ' bad trouble in subroutine newcel of mcrun source particle no. 18859 starting random...

Homework Statement Calculate the value of n so that the approximation is within 0.0001. b = 2, a = 1. f(x) = 1/x. Homework Equations f4(x) = 24/x^5 (Think this is correct) Error <= (b-a)^5/180n^4(MAXx [a,b](f4(x)) The Attempt at a Solution Well, 24/x^5 obtains it's max at x =1...

fatal error. *** cross-section tables are missing from xsdir 10001.70m 10002.70m 10003.70m ... bad trouble in subroutine ixsdir of imcn cannot continue with missing cross-section table(s). is the message I am getting. I have created a link using ln -s...

does a hamming code always corrects one error and detect 2 errors ? and is the distance always 3 ? I know that that is true for (7,4) hamming code but does that apply to a (11,7) or (15,11) ? if not please let me how to get the answers

Homework Statement I need to the probability of bit error in terms of integrals and terms of conditional probabilities. Its a bipolar system using threshold detection https://www.physicsforums.com/attachment.php?attachmentid=58542&stc=1&d=1367888259 Homework Equations probability of...

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...

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...

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...

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

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...

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...

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 =...

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...

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...

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)...

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...

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...

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...

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

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...

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...

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

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...

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

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...

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...