Regression Definition and 361 Threads

Homework Statement We want to determine the coefficients of a polynomial of the form: ##p(x)=c_{1}x^2 +c_{2}x+c_{3}##The polynomial ##p(x)## must satisfy the constraint ##p(1)=1##. We would also like ##p(x)## to satisfy the following 4 constraints: ##p(−1)=5## ##p(0)=−1## ##p(2)=6##...

Hi guys, I have been tasked with the following question; The company has set a fixed budget for Period 1 of the financial year using the following figures as being 100% of the budget: Material costs £200 000 Labour costs £100 000 Variable overheads £50 000 Fixed...

Hi, I was wondering if anyone familiar with excel on a mac can help me? Am i able to do polynomial regression with different x's who contain different amounts of elements? I have three columns, one contains 252 elements, another contains 53, and the last contains 12. They are all closing...

Hi, I've been working on trying to model sales for my work and I'm really just modeling it using exponential regression, so I get the linear regression of the logarithm of the data and obtain the desired formula. What I'm confused about is that if I integrate this to try to predict how many...

This is for an experimental physics homework,I am using the latest version of MS Excel. I have a set of data, I perform linear regression on them and it gives me a line y=ax + b. Given that both a and b have physical significance I would like to know how could I know the uncertainty...

Hi guys, I have run multiple simulations on networks that are all slightly perturbed from each other. They produce slightly different curve outputs onto an x-y graph which I need to now analyse (it has been about 5 years since I did statistical analysis hence why I am here). A couple of the...

Using correlation coefficients as x in a regression?? I was reading an article in the Wall street journal and the author was using a rolling correlation coefficient, on a set of variables, as his predictor variable in a linear regression. Basically it was a uni-variate linear regression , y=...

Hi everyone. I'm a graduate student and am struggling with something that may possibly be trivial. So, my research is creating a mathematical model to represent a real system. I have data points from my real system that I want to compare my model to. How do I do a regression analysis and get...

Homework Statement Ok, so I'm trying to fit a set of data (21000 points to be exact) to a sine function. Homework Equations Y = A*sin(ωt) The Attempt at a Solution I used NumPy to get the parameters A and ω with the least squares method. So far, so good. However, i appear to...

Finding the Uncertainty of the Slope Parameter of a Linear Regression Suppose I have measurements x_i \pm \sigma_{xi} and y_i \pm \sigma_{yi} where \sigma is the uncertainty in the measurement. If I use a linear regression to estimate the value of b in y=a+bx, I'm struggling to find a...

Hello, I am trying to construct a general function/method based on two sets of minimum/maximum data point constraints, which can take on new values in different situations. The only known data for this general function is the starting point (y-axis intercept) and the x-range. The rate of...

I am using linear regression to predict 'y' based on 8 variables. With my example, most the Betas that I got are negative. So, y, the value to predict, is negative. To my data, y is a time in seconds, so I think it shouldn't be negative. I my example in python, and I want to know if y...

Hey guys. I have some trouble understanding how the F-test is used for testing the viability of a regression model. Before I delve into the background/question, just wanted to post a link that discusses the topic briefly: http://www.stat.yale.edu/Courses/1997-98/101/anovareg.htm So, coming...

I'm trying to write some code to do a regression on data weight (x) and time (y). As best as I can tell, the model should be y = b1 + b2ln(x), but I don't know how you can do this by hand (I know how to in R...). I also know how to do a simple linear regression by hand. Can it be done using...

Homework Statement I collect a set of data (n = 100 observations) containing a single predictor and a quantitative response. I then fit a linear regression model to the data, as well as a separate cubic regression. 1) Suppose that the true relationship between X and Y is linear. Consider...

Homework Statement I'm looking through some example problems that my professor posted and this bit doesn't make sense How do you come up with the values underlined? Homework Equations The Attempt at a Solution Upon researching it, I find that you should use α/2 for both...

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...

In a linear regression with 1 independent variable, if X is always the same (let's call I am unlucky), but Y present different values for the same X, I still can find the coefficient of the straight line equation?

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...

I am trying to understand how linear regression and R-squared differ. 1 - Can anyone give me an example of use of linear regression and R-squared? 2 - They have some relation between them? E.g., they are useful for each other? 3 - What are the dangers when analysing the linear regression...

http://imgur.com/LAOgGyY http://imgur.com/LAOgGyY I know the components of R2 as in ESS, TSS, RSS. I know cov(x,y) = [\sum(yi - ybar)(xi - xbar)]/n-1 But that's as far as I can go, I have come across lowercase r yet or the sample correlation and proofing how they all fit is a bit beyond...

I'm trying to find a comprehensive list of the empirical coefficients to be used in the following equation for calculating ideal gas constant pressure heat capacities: \frac{c^{IG}_P}{R}=A+BT+CT^{2}+DT^{-2}+ET^{3}(Eqn. 1) cPIG is the ideal gas constant pressure specific heat capacity; R is...

So I have this set of statistical data, which is not completely relevant to what I want to model, and I would like to compensate for that somehow since I do not have the more precise data. I have about 500 observations of average wages in certain areas which are modeled as dependent on several...

Homework Statement Under the simple linear regression model Y= A + Bx + e, where A is the intercept (a known concept), B is the slope parameter (unknown) and e is a random error term satisfying the normality assumption. If (X1,Y1)...(Xn,Yn) are the n data points observed, find the least squares...

Homework Statement Why does excel give me this: http://postimg.org/image/68b9z1lqt/ And various online calulators (for example http://www.alcula.com/calculators/statistics/linear-regression/), and my own calulations give me this: http://postimg.org/image/kpljm4awx/ Homework...

Homework Statement I have to design an experiment with 3 factors. One factor has to be quantitative with at least 3 levels. One Qualitative with at least 3 levels. And the last one can be either quant/qual with at least 2 levels. My question is in regards to coding the variables. For example...

Homework Statement Hi, I need to create an experiment for my regression class and I would appreciate some ideas which would allow me to generate the data with minimal resources (preferably something on the computer where I can get data instantly) The main criteria for the experiment...

Homework Statement design a regression model that will use the dataset y trial x1 x2 x3 0.08536, 1, -1, -1, -1.00000 0.09026, 2, -1, -1, -1.00000 0.10188, 1, -1, -1, -0.33333 0.09301, 2, -1, -1, -0.33333 0.10362, 1, -1, -1, 0.33333 0.09920, 2, -1, -1...

1. I am trying to determine the value of g based on a simple pendulum. I have graphed a scatter plot with the x-axis as L and the y-axis as P. I have 3 different series for different lengths of pendulum. When I try to find a line of best fit I get something like cx^2 + dx + e and this trend...

A bit confused with this question. my answers are below each question. please help. Branded Products, Inc., based in Halfway Tree is a leading producer and marketer of household laundry detergent and bleach products. About a year ago, Branded products rolled out its new Super Detergent in four...

Jordan from Facebook writes: Help please,

Homework Statement Okay, so the problem I have goes like this: Shown below are the number of galleys for a manuscript (X) and the total dollar cost of correcting typographical errors (Y) in a random sample of recent orders handled by a rime specializing in technical manuscripts. Since Y...

Homework Statement Assume regression model y_i = \alpha + \beta x_i + \epsilon_i with E[\epsilon_i] = 0, E[\epsilon^2] = \sigma^2, E[\epsilon_i \epsilon_j] = 0 where i \ne j. Suppose that we are given data in deviations from sample means. If we regress (y_i-\bar{y}) on (x_i-\bar{x}) without a...

I model arterial baroreflex data that I have collected in humans using the Kent equation which is: y=p1/(1+exp((x-p3)*p2))+p4; where Y=heart rate, X= estimated carotid sinus pressure, p1=range of Y, p2=slope coeff, p3=centerpoint on X, p4 = minimum Y. I use Sigma Plot to do a best fit line...

I have posted this question before but I don't think I was clear on what i was trying to do exactly. I am trying to simulate a set of muon detecting drift tubes in 2d space. I have 2 sets of detector tubes (shown as black circles in the image), a particle trajectory goes through all tubes...

Hello, I'm a second year mathematics and economics student, and I've been hired by an economic development organisation to conduct a research project on the probability of loan default in micro-credit borrowers in rural Kenya (I'll be heading there in person this summer). Basically, I'll...

I'm trying to understand the derivation of polynomial regression. Given data points: [(-1,-1),(2,-1),(6,-2)]. So a 2nd degree curve will be a concave downward parabola. My calculator produces the equation: -0.0357x2+0.0357x-0.9285. Which fits the data good. But if I try to do it manually...

Hi, I am trying to simulate muon paths through drift tubes and I have ran into a problem performing a linear regression. I have generated simulated muon trajectories in 2 dimensions and they passes through my simulated drift tubes represented as black circles with a '+' in the center. As the...

I wasn't sure where to put this question. Can anyone tell me what method LineFit uses to perform linear regression with error in both coordinates? Thank you.

Homework Statement My question is q.3 in the attachment. I don't really understand the scenario of the question. The Attempt at a Solution For (a), if X = 1, will the model become: y = (b_1)(E_1) + epsilon? So (b_i)'s are the slopes of the models? But what is the assumption of the...

I read about "Linear regression" and I want to make sure that what I read is right Just tell if these equations are right- Slope of line of regression for y on x is given by m=\frac{E(XY)-E(X)E(Y)}{E(X^{2})-[E(X)]^{2}} \\ m=\frac{Cov(XY)}{Var(X)} \\ m=\frac{ρσ_{x}σ_{y}}{σ_{x}^{2}} \\...

there are two regreesion model Eviews output... which one is more realistic? model 1: wagehat = 116.9916 + 8.303*IQ model 2: logwagehat = 5.88 + 0.0088*IQ both of them use same samples... do i need to know futher statistic information to judge which one is more realistic? such as...

there are two regreesion model Eviews output... which one is more realistic? model 1: wagehat = 116.9916 + 8.303*IQ model 2: logwagehat = 5.88 + 0.0088*IQ both of them use same samples... do i need to know futher statistic information to judge which one is more realistic? such as...

What's the difference between trends and regression lines (linear and non-linear) which minimize the residual sum of squares?

Homework Statement Any help on this would be immensely appreciated! I am having trouble interpreting what my instructor is trying to say. Consider a simple linear regression model: y_i = \beta_0 + \beta_1x_i + u (a) In regression through the origin, the intercept is assumed to be equal to...

Homework Statement Professor E.Z.Stuff has decided that the least squares estimator is too much trouble. Noting that two points determine a line, Dr. Stuff chooses two points from a sample of size N and draws a line between them, calling the slope of this line the E.Z. estimator of beta1 in...

Homework Statement A rectangular parking lot is to be placed with one side along a building where no fence is required. If 1000 yards of wire are available for fencing the other 3 sides of the lot, what is the maximum area the lot may have, and what are the dimensions of the lot of a maximum...

Hi, I'm learning statistic. Do you guys know how to calculate quadratic regression by hand, which is: give a data set (x,y), find a parabola f(x)=ax^2+bx+c that minimize the total square errors . I have known how to calculate linear regression. Thanks in advanced.

Hello, I'm using this this calculator to determine a rough sample size for a multiple regression (20 predictors). http://www.stattools.net/SSizmreg_Pgm.php I don't really understand the effect size? Could somebody tell me if you are using multiple regression (with 20 predictors)...

Sorry if this is somewhat elementary but the regression form of the sine function with data provided is y=asin(b(x-c))+d As far as I know, all of the variables except c can be determined mathematically. My question is this, using calculus or any other method, is there a way to determine c...