Leslie Matrices for population age distribution modelling

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  • Опубліковано 16 лис 2024

КОМЕНТАРІ • 53

  • @sineadmoss9924
    @sineadmoss9924 8 місяців тому +3

    you are doing the lords work thank you for saving my life before my exam next week

  • @clubpenguin359
    @clubpenguin359 3 роки тому +20

    Is the video flipped or are u a super genius

  • @k_chantale3692
    @k_chantale3692 2 роки тому +6

    This video is a lifesaver!! Very informative and straight forward!

  • @ProfBoggs
    @ProfBoggs 3 роки тому +4

    Thank you for posting this. It shows a very practical use for matrices. And your ability to draw the text backwards is quite a skill.

    • @ProfBoggs
      @ProfBoggs 3 роки тому +2

      @AL17 AMVs Are you sure? If so, do you happen to have a link that shows where I can buy one of these? I would love to have one of these for teaching purposes.

    • @yashpanjrath3807
      @yashpanjrath3807 2 роки тому +7

      he flips the visuals along the vetical axis bruh

  • @user-lv1zs1cn8l
    @user-lv1zs1cn8l 6 місяців тому +1

    This one really cleared my fundamentals..Thank❤

  • @mijopeido
    @mijopeido 3 роки тому +2

    Thank you so much! This video was really helpful.

  • @lileggy9553
    @lileggy9553 4 роки тому +3

    This is very helpful, thanks 👍

  • @majesticeaglesasquatch7324
    @majesticeaglesasquatch7324 Рік тому +2

    Great video Joel - but how do you write on that board?

  • @abezadama6261
    @abezadama6261 2 роки тому

    thanks Sir. I like the content and your skill to explain.

  • @Syntaxxed
    @Syntaxxed 10 місяців тому

    but for example when working with. 4x4 matrix you put S3 further down diagonally? (in row 4 column 4? element 4,4)

  • @mcgkorea9871
    @mcgkorea9871 Рік тому

    Leslie matrices is really interesting and your explanation was very easy to understand. But I wanna ask you what happens if the birth rate or death rate changes?

  • @NatN-hg5xp
    @NatN-hg5xp Рік тому +1

    Great video! Using 400 for each life stage does make it difficult to follow the math as it's broken down, but otherwise it was really informative!

  • @Syntaxxed
    @Syntaxxed 10 місяців тому

    finally I understand.. thank you!

  • @dylansmyth
    @dylansmyth Рік тому +1

    Is there an easy way to make that P10 calculation? My brain can't wrap around how you got 3018, 2557, 365, without actually doing it all by hand. I'm coming from a basic biology background and not a math background. Thanks!

    • @JoelSperanzaMath
      @JoelSperanzaMath  Рік тому +3

      You're really not going to want to do a matrix to the power of ten by hand. Very easy with technology though. I recommend using something like symbolab to help you

    • @dylansmyth
      @dylansmyth Рік тому

      @@JoelSperanzaMath thanks!

  • @billybobcreek1890
    @billybobcreek1890 3 роки тому

    Oi speraza post some Unit 4 specialist stuff surelyyyyyy. Cheers mate

  • @ted5677
    @ted5677 2 роки тому

    could I do this with a 2x2 matrix, just have b1,b2 on the first row then second row: s1, 0

  • @akilaabesinghe7653
    @akilaabesinghe7653 3 роки тому +1

    Thank you very much!

  • @samkelomsomi3111
    @samkelomsomi3111 4 роки тому

    This is very helpful

  • @Komalkomal-cd6fg
    @Komalkomal-cd6fg 2 роки тому

    Thnkxxx from India.

  • @callingwind5071
    @callingwind5071 3 роки тому +1

    Thank you for the video :)! What about migration in this Leslie's model? I am trying to integrate also this important variable. Any idea?

    • @JoelSperanzaMath
      @JoelSperanzaMath  3 роки тому +3

      So much to talk about with migration. You can use an iterative model, first multiplying by your Leslie matrix, then adding a migration matrix. Then repeating that for every period.
      But... Will the population migrating in have the same birth and death rates as those already in the population? In human populations, this often isn't the case.
      If you want to do that differently, you can treat your migrant population as a sub population of the main population, and use a different Leslie matrix on them.
      Remember, it's a mathematical model to predict population, it's not perfect. You create the model based on observations and assumptions that you make.

    •  3 роки тому +1

      This model is designed for a closed population, which refers to a population with no migratory flow in or out, if you would like to learn more about the population growth models, I recommend you the Lotka-Volterra or the Keyfitz model.

  • @cewinharhar7899
    @cewinharhar7899 Рік тому

    amazing

  • @GoatzAreEpic
    @GoatzAreEpic Рік тому

    you are the GOAT

  • @rkit1571
    @rkit1571 2 роки тому +1

    Wow! Such a fab video! Thank you! I do have to ask though - I noticed a question about migration (I presume emigration would have a similar answer minus a change in birth and death rates), but in an applied scenario is it realistic to presume survival rate and birth rate will stay the same after multiple generations? Is there anyway to integrate some form of stochasticity within a Leslie Matrix?

  • @subheemkumar2037
    @subheemkumar2037 3 роки тому

    Thank you 😀

  • @mehrdadkazemi3969
    @mehrdadkazemi3969 2 роки тому

    Thank you so mcuh

  • @ashleysingh2534
    @ashleysingh2534 3 роки тому +1

    What if the time period you’re working with is like 1 or 2 years?

    • @JoelSperanzaMath
      @JoelSperanzaMath  3 роки тому +1

      As long as you state your fertility rate and survival rate in the same time period, everything works just the same.

    • @ashleysingh2534
      @ashleysingh2534 3 роки тому

      @@JoelSperanzaMath oh cool, thank you!

    • @tapiwamatariranwa1100
      @tapiwamatariranwa1100 2 роки тому

      how to calculate net reproductive rate using Leslie matrix model?

  • @FlexThoseMuscles
    @FlexThoseMuscles Рік тому

    Lifesaver ~ this wasn't in any school manuals 🤩

  • @c4rgob0b
    @c4rgob0b 3 роки тому +1

    how exactly is it that you can write backwards so effortlessly ?

    • @JoelSperanzaMath
      @JoelSperanzaMath  3 роки тому +5

      What if I told you I'm not writing backwards?

    • @c4rgob0b
      @c4rgob0b 3 роки тому

      @@JoelSperanzaMath must be magic 😂

    • @ProfBoggs
      @ProfBoggs 3 роки тому

      ​@@JoelSperanzaMath Do you just reverse the image in post-production so the viewer sees it correctly?

    • @denniscolin790
      @denniscolin790 3 роки тому +1

      @@ProfBoggs Could be an option but his watch is still on the right side of the picture, on his left hand, right?

    • @ProfBoggs
      @ProfBoggs 3 роки тому

      @@denniscolin790 Hmmm. Good point. Maybe he is ambidexterous and then ran it through post-production? To quote my 11-year-old, "I am now confuzzled."

  • @juniorlaognamassi8160
    @juniorlaognamassi8160 10 місяців тому

    j'aime la vidéo

  • @jonathanjavid7206
    @jonathanjavid7206 3 роки тому +1

    The equation Pn=L^n * P is not a valid equation the answer will be different from the actual equation which is Pn= L * Pn-1.

    • @JoelSperanzaMath
      @JoelSperanzaMath  3 роки тому +3

      I like your confidence.

    • @jonathanjavid7206
      @jonathanjavid7206 3 роки тому

      @@JoelSperanzaMath I really like your method the way you teach, I try multiple times this square equation but unfortunately couldn't get my desire answer as Compare that I solved through actual equation.

    • @pritam._
      @pritam._ 3 роки тому

      no?

  • @kyleyim2915
    @kyleyim2915 4 роки тому

    how did you get the birth rate exactly?

    • @ViniciusSantos-mv6zt
      @ViniciusSantos-mv6zt 4 роки тому +1

      I think the birth rate is something that get by looking at how many individuals were born after a reproductive event in a certain area. In his case, he is only using data that was already available. I recommend that you look for videos that explain how calculate the birth rate.

  • @Biruk006
    @Biruk006 Рік тому

    1:31 you show the change in the population of kangaroos in 3 years, how did the new 3-6 age range become bigger than the population of the old 0-3 range? or is that just a little mistake?

  • @zoldickkillua6972
    @zoldickkillua6972 3 роки тому

    thank you so much!