topic You'd have to specify in Intel® Fortran Compiler

norm2 for complex vectors

diedro — Wed, 10 Dec 2014 15:35:14 GMT

dear all,

I usually use NORM2 to compute the error in a while cycle.

However, I have complex vector now and NORM2 does not work.

Is there any norm2 function for complex vectors?

Thanks

Not in the Fortran standard -

Steven_L_Intel1 — Wed, 10 Dec 2014 15:39:16 GMT

Not in the Fortran standard - NORM2 is defined for REAL only.

Dear all, Dear Steve,

diedro — Wed, 10 Dec 2014 15:43:14 GMT

Dear all, Dear Steve,

Ok. Do you have some suggestion to overcome this?

this is my code, I use norm2 to compute the error:

 DO WHILE(NORM(R1)>=eps*NORM(BBg))
        !
        P1 = R1 + beta0*P0
       !
       ........
       ........
      .........
   ENDDO

where R1 and BBg are complex vectors

Thanks for any help

You'd have to specify

TimP — Wed, 10 Dec 2014 16:44:14 GMT

You'd have to specify explicitly how you want NORM calculated.

There is a routine NRM2 in

mecej4 — Wed, 10 Dec 2014 17:13:40 GMT

There is a routine NRM2 in MKL, of which the flavors SCNRM2 and DZNRM2 pertain to complex vectors. There is an overloaded routine NRM2 available through the F95 interface.

I can't understand at all why

JVanB — Thu, 11 Dec 2014 01:30:41 GMT

I can't understand at all why NORM2 for complex input isn't in the standard. Stuff like NORM2(transfer(x,[real(kind(x))::])) or NORM2([NORM2(real(x)),NORM2(aimag(x))]) is possible.

Dear all,

diedro — Fri, 12 Dec 2014 08:29:06 GMT

Dear all,

thanks a lot.

NRM2 and NORM2([NORM2(real(x)),NORM2(aimag(x))]) work for me.

I have only to compute the difference between two complex vectors

thanks again