input matrix

Hi,

i'm learning how to use lapack library (in particular, Intel MKL). I
wish to know how I have to format the my inputs. I'm calling lapack
functions from c++ (zhetri. zhemm, zgemm, zhseqr, ztrevc).
I declare the 3x3 matrix (in c++) in this way:
complex MyMatrix[9];

I intend MyMatrix[0], MyMatrix[1], MyMatrix[2] as the first row, but
i'm not sure that also lapack routine interpret this the same way (and
not MyMatrix[0],MyMatrix[3],MyMatrix[6] as the first row).
So, how I have to manage matrixes, column major or row major (like in
c++)?.

Thank you

aberte@gmail.com <aberte@gmail.com> wrote:

> i'm learning how to use lapack library (in particular, Intel MKL). I
> wish to know how I have to format the my inputs. I'm calling lapack
> functions from c++ (zhetri. zhemm, zgemm, zhseqr, ztrevc).
> I declare the 3x3 matrix (in c++) in this way:
> complex MyMatrix[9];

> I intend MyMatrix[0], MyMatrix[1], MyMatrix[2] as the first row, but
> i'm not sure that also lapack routine interpret this the same way (and
> not MyMatrix[0],MyMatrix[3],MyMatrix[6] as the first row).
> So, how I have to manage matrixes, column major or row major (like in
> c++)?.

Fortran stores arrays with the first (leftmost) subscript
varying fastest. If the lapack documentations is described
in those terms, you will store them as MyMatrix[0],
MyMatrix[3], MyMatrix[6].

It seems that zgemm has an argument to specify the form
of the input matrix. You can choose the appropriate one!

-- glen