Regression Definition and 324 Threads

Hi, I want to model a set of a few dozen points on the x-y plane where y can be anywhere from 0 to 100 and x increases by 1 for each point on the y-axis, ex: (1, 26) (2, 84) (3, 2) etc. . . Is it possible to accurately model such a random array of points with an equation? Someone...

My problem in short: I have a set of data, and I want to calculate the linear regression, and the uncertainty of the slope of the linear regression line, based on the uncertainties of the variables My problem in detail: My data is from an experiment and the uncertainties (errors) are...

Hi, I've got what should be a very easy simple linear regression problem, but I can't seem to be able to get my head around it. Here it is: So far I've been trying to sub these values into a regression equation like this one: Y = 5B + (-0.003)B^2 Where "B" is my Beta1 value. I...

Hi, I hope this is the correct section, I am looking for a good starting book about Parametric Regression and Regression Diagnostics. I am currently slogging through "Semi-Parametric regression" Ruppert et-al (2003) and I'd like a slightly easier book that goes slightly more slowly and...

Hi, I've collected some data on the relative permeability of ferrite at various temperatures, subject to a constant external magnetic field and I'd like to fit a curve to the data. I believe that stat-mech theory predicts that \mu_r = 1 + a\tanh(b/T) where T is thermodynamic temperature...

Information Technology is actually a history of regression. I started programming in Basic on Commodores and PCs in the early 80s. It was fast to learn and fast to put ideas into practice. In fact I would argue that 99 % of all IT programming problems were already well solved just using some...

Hey, I have just finished running all the regressions for my thesis and I now have a nice 8-variable regression with an r² if 0.53. Almost all my hypothezised variables are significant. I am now wodering if there is a possibility to somehow test the forecasting accuracy of this model? I am using...

Hey-- I'm writing up a physics lab report on centripetal force; at the moment I've hit a problem with the velocity squared vs. radius graph. The graph *should* show a root curve (v^2 = Fr/m) but all of the regression utilities I've used churn out an exponential curve. Here are the four points...

Hi I'm doing some homework and I have the main question answered but this added one is hurting me. Let me give you the entirity of it... - For each company ABC and XYZ write an exponetial regression equation in the form of a X b^x (Thats A times B to the x), where x = number of yeats and why =...

linear regression where am i going wrong?? Linear regression using least square fit method for the determination of cocaine sample Cocaine (mg/ml) Peak height X= 2.75 Y=27377 X squared=0.9625 X x Y=3241.272 M = 10 x 3241.272 – 2.75 x 27377 / 10 x 0.9625 – 7.5625 =...

Im having some trouble with this, and I was hoping someone could help me. I have a data set from which I've determined the \widehat{a} and \widehat{b} values and determined where the line of best fit should go using linear regression. The next thing I have to do is work out the varience using...

It seems to me that Linear Regression and Linear Least Squares are often used interchangeably, but I believe there to be subtle differences between the two. From what I can tell (for simplicity let's assume the uncertainity is in y only), Linear Regression refers to the general case of fitting...

I just gave a try to a statistical excel add-in and found PCA and FA quite interresting. However, I don't see where are the differences between these two analysis, except for the layout of the results. Additionaly, I see the link with multiple regression, but I don't see the link precisely...

Hey. I tried to make a function that could calculate the function of a "average" line. See my picture: http://home1.stofanet.dk/orhan/regr.jpg The language is danish but if you know about regression you will understand the variables. What have I done wrong? or.han

Hi, I am having some difficulty with this problem: what would be Y^h^a^t if s_y_/_x = 439, n = 24 and 95% confidence interval estimate for the average Y given a particular value of X is 1125 and 1695. ----------------- I know Y^h^a^t = b_o + b_1x but I am not sure how I can use the...

Say i have a set of points that aren't necessarily linear, but are planar, and all follow a 'general' trend in the same direction. Say, something like this: http://img343.imageshack.us/img343/2218/pointdistribution1jo.jpg This is an entirely random example, but hopefully it'll help you...

If the regression equation is y=2.3-1(x) and r^2 = 0.78, what is the value of the coefficient of correlation? my answer was 0.88 and i got it wrong, is it -0.88 because of the negative slope in the equation? please help fast.. thnx

I'm writing a philosophy essay and surfing around the internet and talking to my teacher has led me to believe that some poeple believe that there is some inherent inconsistency in the idea of an infinite regression of causes. I can not think of anything concrete, so does anyone have any ideas...

Hi, Complicated stats question, but maybe someone out there knows how to proceed. I am trying to perform regression on two variables, the samples of which have significant, but known error components. Ordinary least squares regression cannot be used as it is assumed that measurements are made...

Why according to statisticians should a regression line (line of best fit) pass through the mean of x and mean of y? (ie - x bar and y bar) Why does this make the regression line more accurate? Thanks in advance. :-)

I have been trying to figure this out for 2 weeks. A helicopter is begins its horizontal motion 2500 ft from the center of a targe 30 ft above the target traveling at 40mph. The target ( a pile of boxes) is stacked 15 ft high off the ground. At the appropriate time, a person is to jump out...

Hello there. I have just finished a biological experiment on "effect of trypsin concentration on rate of casein hydrolysis" I have already obtained a graph, and I used a program called "Graphpad Prism" to analyse the data usin nonlinear regression (3rd degree polynomial). I have got all the...

Past life regression Has anyone else ever tried this? What did you think. Tsunami and I both tried this. A local author and hypnotist offered free hypnosis and regressions so that he could use the data for his book. Since I had practiced self hypnosis for many years I was sure that I could...

Concrete road pavement gains strength over time as it cures. Highway builders use regression lines to predict the strength after 28 days (when curving is complete) from measurements made after 7 days. Let x be strenth after 7 days (in pounds per square inch) and y the strength after 28 days...