Statistics - Multiple & Nonlinear Regression

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  • เผยแพร่เมื่อ 1 พ.ย. 2024

ความคิดเห็น • 17

  • @DrCraigMcBridePhD
    @DrCraigMcBridePhD  9 ปีที่แล้ว

    Hey Lukas,
    Those are GREAT questions! First off, this video is done for an introductory statistics class that doesn't dive too deep into this stuff, so it was meant mainly as an informational video so that they knew these types of analyses existed, but it wasn't intended to really teach the concepts that much. From the level of your questions, I would guess that you are much farther along! As to the dummy variable point - yes, it would, and I do have a dummy variable for gender (it is called "sex") At 11:21 I show the table of values and you will see gender of the child. At 11:36 you will see the logistic regression equation with "height of child = 25.6 + 0.377(height of mother) + 0.195(height of father) + 4.15(SEX) and the SEX variable is the gender of the child.
    As for using a quadratic to predict growth. Yes, growth is normally THOUGHT of as being exponential, but the data set we had presented a shape that was more closely MODELED by a quadratic. Go to 13:55 and you will see in the table that the exponential model had a slightly smaller correlation coefficient. This reminds us that prediction really only works well within a small window. Our data was only from 1800 to 2000 with only 11 pieces of data! If we had more pieces of data it is highly likely that an exponential would end up fitting it better.

  • @Ecure51
    @Ecure51 7 ปีที่แล้ว

    +DrCraigMcBridePhD
    Thanks for the concise video, I had a question about your comment regarding the influence the order of inputing the predictor variables has on their importance in the model. In the equation Daughter = 7.5 + .707 Mother + .164 Father, I gathered that if the father variable was input first it may have taken on a value closer to .707 and the mother might have take a value closer to .164. How do you account for this potential bias in the process and how often do you encounter this problem? Is it simply putting in variables that logically seem to have more influence in before others?

  • @weldaygebreegziabher4342
    @weldaygebreegziabher4342 6 ปีที่แล้ว

    hi, it seems best. how can be determined critical period of weed competition in crops following non linear regression equations (Gompertz and Logistic equations)under different periods of weed competition and weed free periods in SAS? the synthax used also.

  • @abaynewdemisew9764
    @abaynewdemisew9764 5 ปีที่แล้ว

    Dear Dr Craig Mc , first of all I would like to say thanks for your video. But if possible I have on question " how can I analyise my data set in non linear least square model?'. let me introduce you about my data set . My deprndent variable is return on asset(ROA) which include negative numbers. And my indpenent varibles are degree of operating leverage, degree of financial leverage and total leverage. there is normality problem in my data and my analysis is panel data analysis. so please help me in my thesis work.
    Thanks!

  • @ginamiranda9911
    @ginamiranda9911 9 ปีที่แล้ว

    I have a question: what analysis should I perform if I want to check if a dependent variable (Y) can be described by several independent variables (in my case three (a, b and c) by using a model with quadratic equation. Example: Y = 5 + 2a - 3b + 6c + 2a*b - 8a^2

    • @DrCraigMcBridePhD
      @DrCraigMcBridePhD  9 ปีที่แล้ว

      Gina Miranda If you have actual data, you can simply compare the observed Ys to the predicted Ys and see how good a model the equation is. If you want to do it in a more "official" way, you will need to compute the multiple regression R and R-squared etc.

  • @matheusgulin6810
    @matheusgulin6810 9 ปีที่แล้ว

    hey, i have a question, what if i have no idea what function describes my set of data? Isnt there a way of figuring it out? For example, i have two independent variables that have influence over a dependent one, how can i come up with a equation that better describe it?

    • @DrCraigMcBridePhD
      @DrCraigMcBridePhD  9 ปีที่แล้ว

      You really have to rely on technology to do it for you. If you are familiar with SAS or R, you can use them to compute the best model possible. Unfortunately, with multiple regression, you can no longer rely on a simple scatterplot to show you the relationship. Some programs can give you 3-D plots for multiple variables, but they can be tricky to understand.

  • @melentievr
    @melentievr 6 ปีที่แล้ว

    So how to build Multiple Nonlinear Regression equation (with different variables like x, y, z, d, r, ...m, not x, x^2, x^3, x^n)?

    • @DrCraigMcBridePhD
      @DrCraigMcBridePhD  6 ปีที่แล้ว

      Melentiev Ruslan the variable letters don't matter. All that matters is the level of measurement. If the variables are all ratio level, nothing changes. If they are ordinal or other levels, you may need to run logistic regression or log regression etc

  • @kakarotomargulis9592
    @kakarotomargulis9592 3 ปีที่แล้ว

    How to do the nonlinear regression of this database? I tried to use the logistic growth function and I couldn't.
    The function of logistical growth is Theta1 + (Theta2 - Theta1) / (1 + exp(( X - Theta3) /Theta4 ) ) .
    The database follows below:
    Year Production
    1971,00 40307,355
    1972,00 41224,341
    1973,00 40772,722
    1974,00 40354,975
    1975,00 42628,578
    1976,00 47343,76
    1977,00 52560,846
    1978,00 57252,182
    1979,00 62749,646
    1980,00 65117,867
    1981,00 62518,976
    1982,00 58409,506
    1983,00 57868,732
    1984,00 57234,72
    1985,00 56936,361
    1986,00 57738,2
    1987,00 57346,604
    1988,00 55884,737
    1989,00 51317,959
    1990,00 43725,048
    1991,00 38653,177
    1992,00 34887,414
    1993,00 32659,597
    1994,00 32640,717
    1995,00 34849,654
    1996,00 36473,318
    1997,00 35980,925
    1998,00 33753,108
    1999,00 34206,223
    2000,00 36641,719
    2001,00 37057,075
    2002,00 36471,8
    2003,00 38382,812
    2004,00 41422,114
    2005,00 41250,078
    2006,00 41230,963
    2007,00 43446,29
    2008,00 46860,677
    2009,00 52334,368
    2010,00 54457,968
    2011,00 58310,146
    2012,00 63291
    2013,00 63082
    2014,00 68974
    2015,00 69966
    2016,00 66087
    2017,00 71113
    Note: I tried to reproduce the results obtained from the link below in the Minitab software and I was not able to.
    www.roperld.com/science/uranium.htm

  • @DrCraigMcBridePhD
    @DrCraigMcBridePhD  9 ปีที่แล้ว

    Yes, but the computations are horrendous! It is best to let some form of technology do it for you. If you run the data in SAS or R, it will produce the equation for you.

  • @Jane-ol8fb
    @Jane-ol8fb 8 ปีที่แล้ว

    How did you enter the data into minitab to get the linear regression equation?

    • @DrCraigMcBridePhD
      @DrCraigMcBridePhD  8 ปีที่แล้ว

      I didn't. It was a print-out from a textbook. I use SAS or R, but I am sure there are Minitab tutorials online you can find.

  • @thusarawickramage6023
    @thusarawickramage6023 3 ปีที่แล้ว

    multiple non linear regression and non linear regression both are same?

    • @craigmcbride2135
      @craigmcbride2135 3 ปีที่แล้ว +1

      no. You can have a nonlinear regression line that is fitted to a single predictor variable. You can also have multiple regression lines of best fit that are linear! The shape and number of predictor variables are independent of each other.

    • @thusarawickramage6023
      @thusarawickramage6023 3 ปีที่แล้ว

      @@craigmcbride2135 thank youu