regression

  1. M

    Exponential expansion

    I've got a cell line with a gene that gets bigger exponentially. I cultured the cells from 16/1/17 for 295 days and the gene expanded exponentially. For the second culture, cells from culture 1 frozen on 22/5/17 (d127), were thawed on 2/1/18 and cultured for 196 days. For the third culture...
  2. T

    Need help with multivariate non-linear regression on a sizable dataset

    My dataset is attached (it's just a comma-delimited .txt file - change the extension to ".csv" to open in Excel). In the dataset, I have the following values: dfn h p s ul I need to form an equation that best fits my data and solves for "ul" (ul=?). This will not be a linear equation. I...
  3. O

    Finding the curve of best fit

    Hi, I hope someone can help me with the following question: And this is the data: I used the online graphing technology program called, MyCurveFit, and I got the following data for the following functions: Quadratic: y = 395.3571 - 11.28571*x + 0.1285714*x^2 Exponential(basic): y =...
  4. K

    What do I do after a Principle Component Analysis

    So, I work mainly with biological data, and in this case I have data from environmental measurements such as canopy cover, ground cover, species diversity, etc. I measured this data on 4 sites that were grazed by cattle, then the same measurements were taken after the cattle were removed on the...
  5. D

    Post-hoc power analysis in hierarchical regression

    Hi, I am doing a post-hoc power analysis for hierarchical regression. Is it possible to have the power related to the variation of R-square between the first and the second step of the analysis? Can I just put the value of the R-square variation instead of the R-square? Thank you very much...
  6. C

    What test should I use for the given research question?

    It's been a long time since I took stats and since I've done any quantitative analysis. So I'm stuck... Here is the research question: How closely does perceived susceptibility (a quantitative score was calculated in an assessment) correlate with evidence of risk (based on another assessment...
  7. T

    Regression and Propagation of Error Question

    Hello, I am new to this forum and had a question about propagation of error. I have n independent data sets consisting of mn points on which linear regression was performed for each data set. From these analyses, a slope and corresponding error for the slope were calculated. I want to...
  8. M

    Independent boolean values for Negative Binomial Regression

    Hi, I am trying to analyze some data by using the Negative Binomial Regression. Input for a function of the Python library StatsModels are the independent variable x, containing true (1) or false (0) and corresponding y-values with some double values. Does it make sense to use the Negative...
  9. N

    Model Ratio using Linear Regression

    Hello, I have a question about linear regression modeling on ratio. The original model with dependent variable of ratio is Y= (Y1/ Y2). Both Y1 and Y2 are dollar amount represent sales and balance respectively. The dependent variable Y is a continuous variable between 0 and 1. The equation...
  10. C

    What proportions of censored scores can be modeled with Tobit regression?

    Hey all, I'm looking for guidance on proper use of Tobit models: What proportions of censored scores are reasonable to model with Tobit regression? Say you have a ceiling effect on your dependent variable: As the proportion of scores that are censored approaches 0, it seems there is no need...
  11. G

    Linear Regression Equations

    Hi guys im using Open Office to try to solve math problems and i find its not working for linear equations. That above is the data ive entered into my open office when I try to tun LINEST function or use a t 83 graphing calculator to find the regression equation, I am completely unable to do...
  12. mkmath

    Binary Logistic Regression but everything is significant

    I have a question related to Binary Logistic Regression in SPSS. I have a dataset containing longitudinal data related to deaths. The lived/died (Event) indicator is given by 0(live)/1(die). The dataset contains 10,000,000 observations of 200,000 people. Every person experiences the Event at...
  13. L

    test of logistic regression

    Hello guys! I need your advice. I have done a logistic regression to estimate a probability of impaiment occurs or not. My indep.variables were different factors that can inflduence dep.variable. The data is taken from the stock exchange so it is not normally distributed. I got results from...
  14. M

    (Multiple regression) Can I develop an F-test for zero-intercept?

    (Multiple regression) Can we develop an F-test for testing this hypothesis? RM : H0 : Y = e FM : H1 : Y=B0 + B1X1 + .... + BpXp + e (e : error term, r.v) As I learned, when we want to find the fitted regression equation, we should not neglect intercept part. It should not be considered zero...
  15. K

    Liner Regression Help

    I am doing a medical study for my thesis concerning the number of organs a donor (numbers ranging from from 0-7) will produce given certain circumstances. I am monitoring their blood sugar, ejection fraction, etc (which are whole numbers) but I also have categorical figures such as Race...
  16. M

    'Regression line through the origin' problem

    while I'm studying regression, I thought it would be a little bit simple, because I could draw the regression line by using the formula about beta one & two. But after I met this problem, I get to know that I was wrong. The problem :: Consider fitting a simple linear regression model...
  17. U

    Logistic regression

    Hi again, This one will probably be very simple for those of you well-versed in statistics. I am looking into discriminant analysis at the moment (as per my recent thread in this same sub-forum) and I got onto logistic regression. I came across an example which is as follows: $L_( B | x_1...
  18. P

    Simple Linear Regression Model

    Let a simple linear regression model be: Y_i=\alpha +\beta x_i + e_i \ \ \ (i=1, \cdots ,n) e_i\sim N(0,\sigma ^{2}) Least squares estimator of \alpha , \beta are: \hat{\alpha }=\bar{Y}-\hat{\beta}\bar{x}, \hat{\beta}=\frac{S_{(xY)}}{S_{(xx)}} (S_{(XY)} is defined as...
  19. I

    Correlation and regression

    For two random variable x and y, sigma x= 2.1 and sigma y= 1.8, co-efficient of regression of y on x =0.65, what is the co-efficient of correlation between x and y? How will I relate correlation and regression? And how will the apply the value of co-efficient of regression and what result will i...
  20. G

    Regression Model Results in Excel

    Hi Guys! Here is the regerssion model results I got from Excel. What are those numbers next to Occupation and Dance type Representative of? What would the formula be to predict the score of a 38 year old Actor dancing the cha cha ? Coefficients: Occupation Dance Type Intercept 21.12659...