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Sqrt of matrix - Amer7 - 04-11-2022 08:35 AM
Is there a command for finding a SQRT of all elements in the matrix?
Like if I have a matrix (that varies in size)
[attachment=10582]
Like in this Example if I have 3x3 Matrix (M1)-> then I run cas.diag(M1) i will get matrix 1,9,16
now Is there a command to automatically find SQRT values of 1,9,16 ?
So the answer ends up being a matrix with values 1, 3, 4 ?
RE: Sqrt of matrix - StephenG1CMZ - 04-11-2022 12:43 PM
The cas sqrt(matrix) should help.
RE: Sqrt of matrix - parisse - 04-11-2022 01:09 PM
Code:
apply(sqrt,[[4,1],[2,3]],matrix)RE: Sqrt of matrix - roadrunner - 04-11-2022 01:12 PM
I think what Amer7 wants is a matrix containing the square root of each element of another matrix. If that's true then here's an example of how to do that:
[[1,2],[3,4]]▶M1
MAKEMAT(√(M1(I,J)),2,2)▶M2
Now M2 contains:
[[1,1.41421356237],[1.73205080757,2]]
RE: Sqrt of matrix - parisse - 04-11-2022 04:13 PM
Yes, that's precisely what apply(...) does, sqrt on each element.
RE: Sqrt of matrix - Amer7 - 04-11-2022 04:24 PM
@StephenG1CMZ
This works when In CAS
@ parisse
@roadrunner
It works but I have to know the size of the Matrix.
The issue with my programs is when I get an assignment I never hav the same MatrixDimensions. There are a lot of calculations between the Matrices, that's why I have to write these programs.
How can I call CAS in normal program. Like if I have:
Code:
Begin
Local Nn3,Mm3;
Nn3:=M1+M2;
Now do I write?
#CAS
begin
Mm3:=SQRT(diag(Nn3));
END;
EDITMAT(Mm3,"SQRT values of diagonal elements of Matrix Nn3");
END;RE: Sqrt of matrix - StephenG1CMZ - 04-11-2022 06:07 PM
Is this syntax of any help?
[code]
EXPORT RT()
BEGIN
M1:=[1,3,9];
M1:=CAS("sqrt(M1)");
PRINT(M1);
END;
[\code]
RE: Sqrt of matrix - Amer7 - 04-11-2022 06:24 PM
(04-11-2022 06:07 PM)StephenG1CMZ Wrote: Is this syntax of any help?
[code]
EXPORT RT()
BEGIN
M1:=[1,3,9];
M1:=CAS("sqrt(M1)");
PRINT(M1);
END;
[\code]
Yes this works
CAS("sqrt(Matrix variable)");
Thank you this will make my calculations much faster. Thank you all once again!
RE: Sqrt of matrix - roadrunner - 04-12-2022 12:58 AM
(04-11-2022 04:13 PM)parisse Wrote: Yes, that's precisely what apply(...) does, sqrt on each element.
Of course you are right. I failed to mention that I was referring to StephenG1CMZ's post.
RE: Sqrt of matrix - Albert Chan - 04-12-2022 12:39 PM
(04-11-2022 08:35 AM)Amer7 Wrote: now Is there a command to automatically find SQRT values of 1,9,16 ?
So the answer ends up being a matrix with values 1, 3, 4 ?
HOME> [[1, 9, 16]] .^ 0.5 → [[1, 3, 4]]
This has an advantage by not going thru CAS, which may make sqrt inaccurate.
HOME> M1 := [[0.398, 0.571]]
HOME> M1 .^ 0.5
[[0.630872411824, 0.755645419493]]
HOME> CAS("apply(sqrt, M1)")
[[0.630872411823, 0.755645419492]]
RE: Sqrt of matrix - StephenG1CMZ - 04-12-2022 01:50 PM
(04-11-2022 06:24 PM)Amer7 Wrote:(04-11-2022 06:07 PM)StephenG1CMZ Wrote: Is this syntax of any help?
[code]
EXPORT RT()
BEGIN
M1:=[1,3,9];
M1:=CAS("sqrt(M1)");
PRINT(M1);
END;
[\code]
Yes this works
CAS("sqrt(Matrix variable)");
Thank you this will make my calculations much faster. Thank you all once again!
Note: Whilst sqrt(matrix) can be useful, it's not the same as applying sqrt to each element.