[FLASH-BUGS] bug in hydro flash2.3

[Mike Zingale]

Markus, I believe that that loop in interp is too big, and should only
have to go from 2 to nzn6 (maybe nzn5 actually).  I will look into this.

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Michael Zingale
UCO/Lick Observatory
UCSC
Santa Cruz, CA 95064

phone:  (831) 459-5246 
fax:    (831) 459-5265
e-mail: zingale at ucolick.org
web:    http://www.ucolick.org/~zingale

"Once something has been approved by the Government, It's no longer immoral."
   -- Reverend Lovejoy







On Tue, 10 Jun 2003, Markus Gross wrote:

> Hi!
> 
> I presume my earlier mail now went through fine.
> 
> On another topic (maybe I am lucky and I catch two birds with one stone ...):
> 
> 
> line 96-line 100:
> 
> !!****f* source/hydro/explicit/splot/ppm/interp
> ! assemble the left and right interface values using the quartic polynomial,
> ! Eq. 1.6 from Colella & Woodward
>     
>     do i = 2, nzn6+1
>         ar(i)  = a (i) + coeff5(i) * scrch1(i+1) + coeff3(i) * dela(i+1)
>        ar(i)  = ar(i) + coeff4(i) * dela(i)
>        al(i+1)= ar(i)
>     end do
> 
> 
> This causes a runtime error. This one was bothering for quite a while, but it 
> is so tempting to avoid errors but simply ignoring compiler flags ;-)
> 
> when I look into:
> 
> !!****f* source/hydro/explicit/splot/ppm/coeff
> 
> I find that coeff5(nzn6+1) and coeff3(nzn6+1) are actually not computet!
> 
>     do i = 2, nzn6
>        temporary = 1. / ( scrch1(i) + scrch1(i+2) )
>        coeff3(i) = -temporary * dx(i)   * scrch1(i)   / scrch3(i+1)
>        coeff4(i) =  temporary * dx(i+1) * scrch1(i+2) / scrch2(i+1)
>        coeff5(i) = dx(i) - 2.e00 * (dx(i+1) * coeff3(i) + dx(i) * coeff4(i))
>        coeff5(i) = coeff5(i) / scrch1(i+1)
>     end do
> 
> and hence not initialized!
> 
> I will dig out my copy of Colella & Woodward tonight still, but any hint is 
> of course appreciated.
> 
> Regards,
> 
> Markus.
> 
> _______________________________________________________________
> 
> Markus Gross AMIMechE BEng (Hons.) Mechanical Engineering
> 
> Heriot Watt University Edinburgh
> School of Engineering and Physical Sciences
> James Nasmyth Building
> Edinburgh
> EH14 4AS
> UK
> 
> Member of  IMechE, SPIE, CSME and VDI
> _______________________________________________________________
> 
> further contact:
> 
> Phone   : +44 (0) 131 451 4737
> 
> UNiX talk: talk markus at lasersim.mce.hw.ac.uk
> 
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