+ Reply to Thread
Page 2 of 2 FirstFirst 1 2
Results 16 to 27 of 27

Thread: Regression analysis with independant variable (error) and multiple dependant variable

  1. #16
    Human
    Points: 12,676, Level: 73
    Level completed: 57%, Points required for next Level: 174
    Awards:
    Master Tagger
    GretaGarbo's Avatar
    Posts
    1,362
    Thanks
    455
    Thanked 462 Times in 402 Posts

    Re: Regression analysis with independant variable (error) and multiple dependant vari




    A multiple linear regression model is linear in the parameters (the "betas") but not necessarily linear in the variables: So this is a linear model:

    y = beta0 + beta1*speed + beta2*speed^2 + beta3*log(voltage) + beta4*sin(angle) + beta5*temp + epsilon

    Where y is the dependent variable (Eloks positional deviation) and epsilon a random disturbance term (that in statistical jargon often is called an "error term").

    In most statistical software you just "mention what explanatory variables you want to have". (In spss you click in then in a box for independent variables). What is Eloks software?

    In R you do:

    Code: 
    lm( y ~ speed + speed^2 + log(voltage) + sin(angle) + temp)
    If Elok is completely unfamiliar with multiple regression I would sugest to consider an statistical experimental plan. It is better with a carefully design plan with 20 - 30 experimental points, than 1000 messy observational points. I suggest to vary two variables, like speed and voltage, each on high and low values.

  2. #17
    Points: 46, Level: 1
    Level completed: 92%, Points required for next Level: 4

    Posts
    13
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Re: Regression analysis with independant variable (error) and multiple dependant vari

    I'm using Matlab but I can open to others software. I got a backgound in programming so I don't mind learning software of language.

    But I'm not sure I follow GretaGarbo's example, but the link I posted in another post is giving me a lot of help so far.

  3. #18
    Omega Contributor
    Points: 38,334, Level: 100
    Level completed: 0%, Points required for next Level: 0
    hlsmith's Avatar
    Location
    Not Ames, IA
    Posts
    6,998
    Thanks
    398
    Thanked 1,186 Times in 1,147 Posts

    Re: Regression analysis with independant variable (error) and multiple dependant vari

    Tell us about your awesome 3-D printer? What do you typically print?
    Stop cowardice, ban guns!

  4. #19
    Points: 46, Level: 1
    Level completed: 92%, Points required for next Level: 4

    Posts
    13
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Re: Regression analysis with independant variable (error) and multiple dependant vari

    I can't, sorry :P

  5. #20
    Points: 46, Level: 1
    Level completed: 92%, Points required for next Level: 4

    Posts
    13
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Re: Regression analysis with independant variable (error) and multiple dependant vari

    Anyway, back to the subject, does anyone of you know how to make this sort of "Polynomial Multiple Regression analysis" like this one? Just show me how I can calculate the curved grid of the picture from a database of [10000 x 3] value. It's all I need.
    Last edited by Elok; 11-20-2014 at 01:22 PM.

  6. #21
    Omega Contributor
    Points: 38,334, Level: 100
    Level completed: 0%, Points required for next Level: 0
    hlsmith's Avatar
    Location
    Not Ames, IA
    Posts
    6,998
    Thanks
    398
    Thanked 1,186 Times in 1,147 Posts

    Re: Regression analysis with independant variable (error) and multiple dependant vari

    It looks like a 3-D correlation or Spline. Have you looked up Spline Regression yet?
    Stop cowardice, ban guns!

  7. #22
    Points: 46, Level: 1
    Level completed: 92%, Points required for next Level: 4

    Posts
    13
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Re: Regression analysis with independant variable (error) and multiple dependant vari

    Quote Originally Posted by hlsmith View Post
    It looks like a 3-D correlation or Spline. Have you looked up Spline Regression yet?
    Will do thanks!

    I also have a friend that told me about a tool on MatLab called Curve fitting tool. Will check that also.

  8. #23
    Human
    Points: 12,676, Level: 73
    Level completed: 57%, Points required for next Level: 174
    Awards:
    Master Tagger
    GretaGarbo's Avatar
    Posts
    1,362
    Thanks
    455
    Thanked 462 Times in 402 Posts

    Re: Regression analysis with independant variable (error) and multiple dependant vari

    oh, he just want to know how to make that graph of the linear regression with polynomials. Not how to analyse the data or do significance test or anything.

    But matlab is a quite old program so I don't think anybody here is particularly enthusiastic about that one. Here is an R link.

    If the results matter to you, (I agree with PeterFlom) go and talk to a statistician.

  9. #24
    Points: 46, Level: 1
    Level completed: 92%, Points required for next Level: 4

    Posts
    13
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Re: Regression analysis with independant variable (error) and multiple dependant vari

    I've read a lot about R and it's performance seem abysimal even compared to MatLab. I was thinking about either Python (anaconda package seem quite awesome) or another program I don't remember the name that my university is offering for free (StatGraphic or something with stat in the name).

  10. #25
    Human
    Points: 12,676, Level: 73
    Level completed: 57%, Points required for next Level: 174
    Awards:
    Master Tagger
    GretaGarbo's Avatar
    Posts
    1,362
    Thanks
    455
    Thanked 462 Times in 402 Posts

    Re: Regression analysis with independant variable (error) and multiple dependant vari

    R - abysmal?

    Such a simple computation can be done in much less than a second.

    But you can download it for free, and start working with it faster than it takes you to walk to, or call, the university administrator to ask for allowance to use statgraphics. R has got 6000 extra packages. Do you think statgraphics has got 60? But you Elok only need the base version and and to study the basic of multiple linear regression.

  11. #26
    Omega Contributor
    Points: 38,334, Level: 100
    Level completed: 0%, Points required for next Level: 0
    hlsmith's Avatar
    Location
    Not Ames, IA
    Posts
    6,998
    Thanks
    398
    Thanked 1,186 Times in 1,147 Posts

    Re: Regression analysis with independant variable (error) and multiple dependant vari

    I dont know GG that linked graph is not as cool as his attached image.
    Stop cowardice, ban guns!

  12. #27
    TS Contributor
    Points: 17,775, Level: 84
    Level completed: 85%, Points required for next Level: 75
    Karabiner's Avatar
    Location
    FC Schalke 04, Germany
    Posts
    2,541
    Thanks
    56
    Thanked 640 Times in 602 Posts

    Re: Regression analysis with independant variable (error) and multiple dependant vari


    But even if each of those individuals parameters doesn't explain my error perfectly, I highly confident a combination of 2-3-4 parameter would have a really high r2.
    Don't forget the possible interactions between parameters.

+ Reply to Thread
Page 2 of 2 FirstFirst 1 2

           




Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts






Advertise on Talk Stats