For n = 2 … 11 set up Vandermonde matrix A of size m × n and for each n given data set a. Matlab





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I am given set of 50 data points with values {a^(i),b^(i)} for i=1,...,50
stored in the arrays a and b.
I know that the Vandermonde matrix A has size m x n, where n = 2 ... 11 and m is the size of the array a.



I want to to fit the data with a polynomial of degree (n − 1), for n = 2,...,11. To do that for each n I have to set up the Vandermonde matrix A of size m × n.



The Vandermonde matrix A solves the following equation:
A^T*A*x = A^T*b



Where the A^T is the transpose matrix and I have b already given.
Also we know that Aij = (a^(i))^(j−1) for j = 1,...,n,
What confuses me is how to set the matrix for n = 2,..,11.



What my line of thought is:
I have m = length(a); this will set up m = 50;



n = 11;



Then A=ones(m,n); This creates a matrix A filled with ones that has the correct size.



However I am not sure how to populate the matrix.
I wrote the following for loop which I thought will populate the matrix:



for n = 2:11
j=n;
for i = 1:50
A(i,n) = (a^(i))^(j-1);
end
end


Could you help me please with setting up the matrix?










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    0















    I am given set of 50 data points with values {a^(i),b^(i)} for i=1,...,50
    stored in the arrays a and b.
    I know that the Vandermonde matrix A has size m x n, where n = 2 ... 11 and m is the size of the array a.



    I want to to fit the data with a polynomial of degree (n − 1), for n = 2,...,11. To do that for each n I have to set up the Vandermonde matrix A of size m × n.



    The Vandermonde matrix A solves the following equation:
    A^T*A*x = A^T*b



    Where the A^T is the transpose matrix and I have b already given.
    Also we know that Aij = (a^(i))^(j−1) for j = 1,...,n,
    What confuses me is how to set the matrix for n = 2,..,11.



    What my line of thought is:
    I have m = length(a); this will set up m = 50;



    n = 11;



    Then A=ones(m,n); This creates a matrix A filled with ones that has the correct size.



    However I am not sure how to populate the matrix.
    I wrote the following for loop which I thought will populate the matrix:



    for n = 2:11
    j=n;
    for i = 1:50
    A(i,n) = (a^(i))^(j-1);
    end
    end


    Could you help me please with setting up the matrix?










    share|improve this question

























      0












      0








      0








      I am given set of 50 data points with values {a^(i),b^(i)} for i=1,...,50
      stored in the arrays a and b.
      I know that the Vandermonde matrix A has size m x n, where n = 2 ... 11 and m is the size of the array a.



      I want to to fit the data with a polynomial of degree (n − 1), for n = 2,...,11. To do that for each n I have to set up the Vandermonde matrix A of size m × n.



      The Vandermonde matrix A solves the following equation:
      A^T*A*x = A^T*b



      Where the A^T is the transpose matrix and I have b already given.
      Also we know that Aij = (a^(i))^(j−1) for j = 1,...,n,
      What confuses me is how to set the matrix for n = 2,..,11.



      What my line of thought is:
      I have m = length(a); this will set up m = 50;



      n = 11;



      Then A=ones(m,n); This creates a matrix A filled with ones that has the correct size.



      However I am not sure how to populate the matrix.
      I wrote the following for loop which I thought will populate the matrix:



      for n = 2:11
      j=n;
      for i = 1:50
      A(i,n) = (a^(i))^(j-1);
      end
      end


      Could you help me please with setting up the matrix?










      share|improve this question














      I am given set of 50 data points with values {a^(i),b^(i)} for i=1,...,50
      stored in the arrays a and b.
      I know that the Vandermonde matrix A has size m x n, where n = 2 ... 11 and m is the size of the array a.



      I want to to fit the data with a polynomial of degree (n − 1), for n = 2,...,11. To do that for each n I have to set up the Vandermonde matrix A of size m × n.



      The Vandermonde matrix A solves the following equation:
      A^T*A*x = A^T*b



      Where the A^T is the transpose matrix and I have b already given.
      Also we know that Aij = (a^(i))^(j−1) for j = 1,...,n,
      What confuses me is how to set the matrix for n = 2,..,11.



      What my line of thought is:
      I have m = length(a); this will set up m = 50;



      n = 11;



      Then A=ones(m,n); This creates a matrix A filled with ones that has the correct size.



      However I am not sure how to populate the matrix.
      I wrote the following for loop which I thought will populate the matrix:



      for n = 2:11
      j=n;
      for i = 1:50
      A(i,n) = (a^(i))^(j-1);
      end
      end


      Could you help me please with setting up the matrix?







      matlab matrix






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      asked Nov 26 '18 at 22:27









      Lachezar PetkovLachezar Petkov

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          You should use the vander function. However, vander will return an m x m matrix, which is usually used to fit the data to a polynomial of degree (m-1). Since you want to fit to a polynomial of degree (n-1), you only need the last n columns of that matrix.



          Here's the code:



          A = vander(a);
          A = A(:,end-n+1:end);





          share|improve this answer


























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            1 Answer
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            You should use the vander function. However, vander will return an m x m matrix, which is usually used to fit the data to a polynomial of degree (m-1). Since you want to fit to a polynomial of degree (n-1), you only need the last n columns of that matrix.



            Here's the code:



            A = vander(a);
            A = A(:,end-n+1:end);





            share|improve this answer






























              0














              You should use the vander function. However, vander will return an m x m matrix, which is usually used to fit the data to a polynomial of degree (m-1). Since you want to fit to a polynomial of degree (n-1), you only need the last n columns of that matrix.



              Here's the code:



              A = vander(a);
              A = A(:,end-n+1:end);





              share|improve this answer




























                0












                0








                0







                You should use the vander function. However, vander will return an m x m matrix, which is usually used to fit the data to a polynomial of degree (m-1). Since you want to fit to a polynomial of degree (n-1), you only need the last n columns of that matrix.



                Here's the code:



                A = vander(a);
                A = A(:,end-n+1:end);





                share|improve this answer















                You should use the vander function. However, vander will return an m x m matrix, which is usually used to fit the data to a polynomial of degree (m-1). Since you want to fit to a polynomial of degree (n-1), you only need the last n columns of that matrix.



                Here's the code:



                A = vander(a);
                A = A(:,end-n+1:end);






                share|improve this answer














                share|improve this answer



                share|improve this answer








                edited Nov 27 '18 at 3:12

























                answered Nov 27 '18 at 0:44









                SavithruSavithru

                592511




                592511
































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