HP Forums - Bad argument type, DET(M9)/M8(2,1) in App

eg1. how([1,4,3,2,1,4,4])--> Error: Bad argument type, M0(B,A):=-DET(M9)/M8(2,1) cant be executed.

eg2. how([1,4,k,2,1,4,4])-> expecting [1,k,1,4] into M0 but Error: Bad argument type

Code:

#pragma mode( separator(.,;) integer(h32) )

exc();

dett();

#cas

how(den):= //"Error: Bad argument type if variable say k is insert into the vector den"

BEGIN

n:=length(den);

m:=length(den);

nx:=simplify(poly2symb(den));

IF even(n-1) THEN rw:=((n-1)/2)+1; ELSE rw:=(n)/2 END;

M0:=makemat(n,rw);

c:=0;

WHILE n>0 DO

    a:=1;L1:={};c:=c+1;

    IF n==0 THEN       

       L1(a):=coeff(nx,n); 

    ELSE

       nl:=n-1;

       FOR j FROM c TO length(den) STEP 2 DO

           L1(a):=coeff(nx,x,nl); // "Error: Bad argument type"

           a:=a+1;

           nl:=nl-2;

       END;

    END;

    L2(n):=length(L1);

    FOR j FROM 1 TO length(L1) DO

        M0(c,j):=L1(j);

    END;

n:=n-1;

END;

hw:=M0;

exc();

END;

#end

#cas  

exc()

BEGIN

FOR j FROM 1 TO m-2 DO

    k:=j+1;

    B:=j;

    M8:=subMat(M0,j,1..rw,k,1..rw);

    dett();

END;

END;

#end

#cas 

dett()

BEGIN

//M9:=subMat(M8,1,1,2,2);

M9:=matrix(2,2);

B:=B+2;

A:=1;

    FOR j FROM 2 TO rw DO

        M9(1,1):=M8(1,1);

        M9(2,1):=M8(2,1);

        M9(1,2):=M8(1,j);

        M9(2,2):=M8(2,j);    

        M0(B,A):=-DET(M9)/M8(2,1); //"Error: Bad argument type"

        A:=A+1;

    END;

END;

#end

Hello,

The problem here is that the result of the -DET(M9)/M8(2,1) is not a number, it's a fraction. And this symbolic object can not be stored in a purely numerical 'Home) matrix (M0).

Your program does mix CAS and Home, which, despite being ok in lots of cases, can sometimes lead to strange things.

My #1 advice would be to use CAS variables rather than home variables for your CAS programs.
If you do want to store the data in a home variables, add an evalf around the -DET(M9)/M8(2,1) code: M0(B,A):=evalf(-DET(M9)/M8(2,1));
and it should work.

cyrille

(01-15-2016 07:43 AM)cyrille de brébisson Wrote: [ -> ]Hello,

The problem here is that the result of the -DET(M9)/M8(2,1) is not a number, it's a fraction. And this symbolic object can not be stored in a purely numerical 'Home) matrix (M0).

Your program does mix CAS and Home, which, despite being ok in lots of cases, can sometimes lead to strange things.

My #1 advice would be to use CAS variables rather than home variables for your CAS programs.
If you do want to store the data in a home variables, add an evalf around the -DET(M9)/M8(2,1) code: M0(B,A):=evalf(-DET(M9)/M8(2,1));
and it should work.

cyrille

..Thanks Cyrille,
there is problem of defining a especially matrix under CAS variables....say , M25:=makemat(n,rw);
FOR j FROM 1 TO length(L1) DO
M25(c,j):=L1(j);
END;
Prime seems to have a hard time defining M25 as a matrix, instead it defines M25 as a function(M25(c,j)). hence i am forced to used Home variables M0 instead which would not work on how([1,4,k,2,1,4,4]) containing a variable k for symbolic manipulation under CAS.

(01-15-2016 10:48 AM)toshk Wrote: [ -> ]
(01-15-2016 07:43 AM)cyrille de brébisson Wrote: [ -> ]Hello,

The problem here is that the result of the -DET(M9)/M8(2,1) is not a number, it's a fraction. And this symbolic object can not be stored in a purely numerical 'Home) matrix (M0).

Your program does mix CAS and Home, which, despite being ok in lots of cases, can sometimes lead to strange things.

My #1 advice would be to use CAS variables rather than home variables for your CAS programs.
If you do want to store the data in a home variables, add an evalf around the -DET(M9)/M8(2,1) code: M0(B,A):=evalf(-DET(M9)/M8(2,1));
and it should work.

cyrille
..Thanks Cyrille,
there is problem of defining a especially matrix under CAS variables....say , M25:=makemat(n,rw);
FOR j FROM 1 TO length(L1) DO
M25(c,j):=L1(j);
END;
Prime seems to have a hard time defining M25 as a matrix, instead it defines M25 as a function(M25(c,j)). hence i am forced to used Home variables M0 instead which would not work on how([1,4,k,2,1,4,4]) containing a variable k for symbolic manipulation under CAS.

Use M25[c,j]:=L1(j) instead. From a syntax point of view, no one would know whether you are creating a CAS function named M25 or if you are referring to the cell of a matrix named M25 because the syntax looks exactly the same. Therefore, to avoid ambiguity, use the square brackets for matrices since functions cannot be defined using square brackets.

(01-15-2016 05:13 PM)Han Wrote: [ -> ]
(01-15-2016 10:48 AM)toshk Wrote: [ -> ]..Thanks Cyrille,
there is problem of defining a especially matrix under CAS variables....say , M25:=makemat(n,rw);
FOR j FROM 1 TO length(L1) DO
M25(c,j):=L1(j);
END;
Prime seems to have a hard time defining M25 as a matrix, instead it defines M25 as a function(M25(c,j)). hence i am forced to used Home variables M0 instead which would not work on how([1,4,k,2,1,4,4]) containing a variable k for symbolic manipulation under CAS.

Use M25[c,j]:=L1(j) instead. From a syntax point of view, no one would know whether you are creating a CAS function named M25 or if you are referring to the cell of a matrix named M25 because the syntax looks exactly the same. Therefore, to avoid ambiguity, use the square brackets for matrices since functions cannot be defined using square brackets.

....thanks Han!!