Error Definition and 998 Threads

Hi, I have a 2 sets (f and y) of 1000 data points each. Also, each data point corresponds to one in the other set. Essentially, I wanted to compute the standard deviation between the two sets, and I did this: ## \sigma_1 = ## IMAGE 1 (check attachment) ## \sigma_2 = ## IMAGE 2 (check...

Sorry if the answer is very simple, but I just had a question regarding error propagation when using a modulo operator in intermediate steps. For example, I have ## \theta = arctan(\frac {A}{B}) ## and then I do ## \theta ## % ##2\pi## (modulo ##2\pi##). This gives me an answer between ##...

Orodruin submitted a new PF Insights post Plus/minus What? How to Interpret Error Bars Continue reading the Original PF Insights Post.

I know its written in greek but i think its a common problem...any ideas? i think that's why the "build 7061" geniunity problem appears. :(

I accept that what I write below will be unpopular and argued with vehemently, however I think it should be considered with an open mind and recognised for the sense that it has. Originally the concept of an expanding universe (and therefore by extrapolation the concept of the Big Bang that...

Hi, I imagined this device and I don't understand where is the error. I posted here because it's a simple mechanical device, I have trouble with the sum of torque. The potential energy must be constant. I think I forgot a torque, if you see where ? A torus turns counterclockwise around the...

Homework Statement So I'm currently modifying an example Symbolic Regression program that uses genetic programming, a type of evolutionary algorithm. I'm using the python deap library. Not sure if anyone on here is familiar with it, but I think that the error is more general to a misuse of...

Homework Statement Hi, with regards to the negative zero error , do we read the vernier scale from the left or from the right? In this case, should it be -0.04cm or -0.06cm? Thank you !

Homework Statement "An instrument (oscilloscope) is prepared to measure a sinusoidal periodic wave, compute the measurement error if the same instrument is used to measure the wave indicated in figure 1 (The wave is much more like a sawtooth wave, sorry for bad drawing)Homework Equations...

I think I found an error in a webassign problem. What do you think?

I really like the book, its the first physics textbook that I liked actually. But I've found a minor error. On page 8 (chapter 1 The Wave Function) it says that if you sum deviations from average of a random variable you'd get zero because " Δj is as often negative as positive", here's the...

I am having an issue with the declared type of the return value of a function not being recognized in its call. This function clearly has its return value declared as complex*16: !----------4-vector dot product under Minkowski metric---------- function dot4(v1,v2) result(res) implicit none...

Hello I have a doubt with the least squares fitting (linear fitting). The low-level statistics textbooks only take into account the statistical error of fitting, but not the error of the fitted points. How is the error of the fitted points taken into account, and included in the total error...

Hi there, I have a quick question to report some numbers on an experiment. I made measurements of fluorescence in a titration of a chemical. The titrations were 1:2 serial dilutions so I report each fluorescence as a function of the log2 concentration: concentration chemical x: 1 , 0.5, 0.25...

How to calculate the permissible error? A force F is applied on a square plate of size L . If the percentage error in determination of L is 2% and that in F is 4% . What will be the permissible error in pressure?

Gurus, can you help please? I've been given a set of samples, each has different sample size and mean (but not individual observations). I'm trying to figure out the population standard deviation so that I can estimate required sample size for certain confidence intervals. My question is how...

Homework Statement Prove: Hint: Group the terms in the error as ##(a_{n+1}+a_{n+2})+(a_{n+3}+a_{n+4})+\cdots## to show that the error has the same sign as ##a_{n+1}##. Then group them as ##a_{n+1}+(a_{n+2}+a_{n+3})+(a_{n+4}+a_{n+5})+\cdots## to show that the error has magnitude less than...

Every time I try to open Intel XDK it comes up with the error message that is attached. It gives instructions on what to do to allow the ports, and I've attached the screen shots of what I've done in control panel- so in firewall, (with the new windows I can't get to the 'exceptions' tab and I...

(Change in momentum is the area under a force against time curve.) (Force is the time derivative of momentum.) Using separation of varibles, you get Fdt=dp. Integrate both sides, you get that the integral of Force with respect to time is equal to p. This seems to imply that p, momentum, is...

You prepare 0.5 liters of a solution by adding 0.75 moles of a weak acid HA to water. For HA, Ka = 10^-1 Finally you dilute this solution to a final volume of 2.0 liters. What is the pH of the diluted solution? My solution is this. [HA] = .75 mol /.5 L = 1.5 M. HA + H2O -> H3O+ + A-. If x...

I had these code in this forum but comes out error as below, any suggestion? Error 1 error C4430: missing type specifier - int assumed. Note: C++ does not support default-int c:\users\username\documents\visual studio 2010\projects\fdm 001\fdm 001\explicit 001.cpp 27 Error 2...

First of all, I am sorry if this is in the wrong subforum; I'm not sure if astrodynamics should be under astronomy. The post is also fairly long. My problem is that in my derivation of the center of mass of a binary system, I get a conflicting result for the distances of the center of mass to...

Is there an error, perhaps typographical, in the famous 1939 Oppenheimer-Snyder paper "On Continued Gravitational Contraction" (Phys Rev v56 Sept 1, 1956 pp 455-459)? Do the units balance in equation 37? The last term inside the last parantheses ##\frac{3r_0^{1/2} \tau}{2R_b^2}## where...

Dear Forum users, I am running a program called NMTO package for constructing Wannier functions for a material. It uses a code plotnmto.f90 to calculate wannier isosurfaces within the mesh defined by me. I compiled the code in gfortran. After defining the mesh when I ran the program for...

kreil submitted a new PF Insights post 5 Common MATLAB Error Messages and How to Fix Them Continue reading the Original PF Insights Post.

Homework Statement The density of a cylinder is calculated from the following data: mass m= (9.1±1.1)g , diameter d = (2.8±0.2) cm , and height H= (4.1±0.6) cm. The error on the density, before rounding, is ( in g /cm3 ) Homework EquationsThe Attempt at a Solution

Note that the code I am using is Python. Currently, I am attempting to numerically solve the equations of state that give rise to the Chandrasekar limit for a white dwarf star. My code works for a simple harmonic oscillator given the correct equations of motion, but does not compute the correct...

Homework Statement It is known that the theoretical resistivity of copper is approximately: 2*10^-8 Ωm. But after I conducted an experiment to find the resistivity of copper, the results turned out to be: 1.68*10^-8Ωm. This is a very small error that can be easily dismissed due to "human...

Homework Statement The circumference of a sphere was measured to be 90 cm with a possible error of 0.5 cm. Use differentials to estimate the maximum error in the calculated volume. Homework Equations Volume of sphere: V=4/3πR3 Circumference of Sphere: C=2πR ΔC = 0.5 cm The Attempt at a...

Homework Statement I am given a frequency value of 95 GHz (9.5x10^10 Hz), C= 25 F, L=1.12x10^(-25) H. The question is to find the uncertainties in frequency by taking account of inductor being 5% accurate & capacitor being 8% accurate. Homework Equations I believe this is the correct formula...

Hi, I have a project at uni where I am making an approximate analytical expression for a parameter and comparing the result with more rigorous simulations. The thing is: the parameter I am comparing is the 2d-integral of the results from the simulations over some area, and the simulation results...

Hi everybody I'm a newbie and working on LM324 to learn Op-Amp. this is my circuit: http://img4.uplood.fr/free/qx3o_20150425_172843.jpg One of the resistors is 217ohm and another 978ohm. then the gain should be 4.50691 as you can see. so far so good. I know this is for ideal Op-Amp. I applied...

Homework Statement [/B] 1. After a long road trip during summer break, a college student wants to estimate how long she drove between rest stops. She takes a random sample of 15 stops and records this data in hours: 1.5, 2.6, 1.75, 3.5, 2.25, 3.75, 1.8, 2.9, 3.2, 3.15, 1.5, 2, 3, 2.75, and...

class Cellphone { private String brand; private long serialNumber; private double Price; public Cellphone (String br, long sN, double Pr) { brand= br; serialNumber = sN; Price = Pr; } public Cellphone(Cellphone aCellphone)...

I'm looking for how to mathematically relate X and Y, in such a way that the Chi-Squared per degree of freedom is minimised. However I can't understand how this would work, given that I'm trying to use known X,Y dX and dY (errors) values, to get the related gradient and intercept for the line of...

Typically in problems involving binary classification (i.e. radar detection, medical testing), one will try to find a binary classification scheme that minimizes the total probability of error. For example, consider a radar detection system where a signal is corrupted with noise, so that if the...

The lab called on us to use a vacuum tube to determine an electron's charge to mass ratio. Here is a link to the lab: http://www.clemson.edu/ces/phoenix/labs/cupol/eoverm/index.html. What are some sources of error in this lab? I already know that human error and error in measurement can skew...

Hey guys, I'm pretty new and desperate. I been trying to compile this program for a while and keep jumping from error to error. Currently I have the following error: Error: Rank mismatch in argument 't' at (1) (scalar and rank-1) I have checked that my arrays are correctly. I have checked that...

I have a sample size of 100 experiments out of which 15 are unfavorable events. I do this measurement for different initial conditions of my experiment. The sample size remains constant but the no. of unfavorable events change in each case. I calculate the probability of success in each case...

Homework Statement Investigating the effect of mass on the period of oscillation. This experiment is about SHM of a floating cylinder, and the theory is explained in this website: http://physics.stackexchange.com/questions/64154/shm-of-floating-objects Also, I'm attaching a diagram of my...

Hello, i have a optical signal(x is length in pixels and y is amplitude ) and i have found a number of FWHM values of peaks. The width is measured in pixels, let's say the average width of 50 peaks is 8,7 pixels, standard deviation is 0,6 and the average amplitude of peaks is 38 and standard...

Homework Statement Homework Equations And the volume element dV expressed in spherical coordinates. The Attempt at a Solution Can you spot where I've made an error?

Homework Statement The wing of an insect is 1.7 mm long. When viewed through a microscope, the image is 1.4 m long and is located 5.9 m away. Determine the angular magnification. Homework Equations di/do=hi/ho M=beta/alpha alpha=object size/object distance beta=image size/image distance The...

I am getting a little confused on which error propagation to use: I am looking to calculate the error in B*Cos(θ) , for the vertical axis of a williamson hall plot. where B is fwhm of a peak with it's own error and cos of the bragg angle I am unsure of whether i need to use partial derivative...

I use Internet Explorer to get into my sbcglobal.net email. It has been working fine all these years. All of a sudden, my desktop gives me Certificate error when I click the "Mail" in Yahoo page. The message is: Security certificate presented by the website has expired or not yet valid...

Homework Statement I need a program where the program needs to ask me a name of a student and then a grade. 1) The program needs to end if a 0 is entered. 2) If the name has a number in it, the program should ask the user to enter another name. 3) After the name is correctly entered the program...

Hello everyone! I'm trying hard to solve numerically a system of coupled differential equations of first order, but I get this error everytime.. I can't find the reason.. maybe you can help me, I'd really apreciate that. This is the code: Jg=0.000043; Kg=0.5; Bg=0.06; Bpm=0.5; r=0.11...

Homework Statement Homework Equations Given above The Attempt at a Solution I used polyfit, but my mean swuare errors are way bigger than they should be- don't see what is wrong with my code! My code is ugly btw, my apologies. %Hw 7 clear all close all y3=[1960; 1965; 1970; 1975; 1980...

Hi, I have 3 values for data set 1 (1a, 1b, 1c), and 3 values for data set 2 (2a, 2b, 2c). (assume set 1 are the ones being compared to) I know that to work out the error percentage for 1a and 2a -- it is the difference (of 1a and 2a) divided by 1a x 100. I can do the same with 1b and 2b, and...

Homework Statement I am doing a lab report and I have to find the slope of a graph as well as the max and min lines of the graph. I also have to find the error in the slope. I have calculated the slope. My first problem is in calculating the error lines. My teacher said i must find the slope...