uote=abhosekar post_id=29253 time=1637252514 user_id=1684]
what you show in equations and what you are writing in GAMS are two very different equations. Which one is right?
Based on what you wrote, your equation should be
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ir =g= 0.0055*Qi**(-0.47)
ir =l= 4.65*Qf**(-0.67)
not sure how that translates to what you have in the code block.
- Atharv
[/quote]
Hi,
Yes, it is different
If I put as
Code: Select all
ir =g= 0.0055*Qi**(-0.47)
ir =l= 4.65*Qf**(-0.67)
GAMS return
Code: Select all
8 error(s): vcPower: FUNC DOMAIN: x**c, x=0, c<0
If I put as
Code: Select all
ir *Qi**(0.47)=g= 0.0055
ir*Qf**(0.67) =l= 4.65
GAMS return
Code: Select all
3 warning(s): vcPower: GRAD SINGULAR: x**c, x=0, 0<c<1
So I changed
" **(-0.47)", and I multiplied Q to the other side of the equation.
0,47 to a fraction (7/15) and 0,67 (2/3), because GAMS does not accept an exponential number lower than 1.
Code: Select all
ir**15*(Qi)**7 =g= 0.0055**12 ;
ir**3 *(Qf)**2 =l= 4.65 **3 ;
This is the form that I not obtain an error.
But returns
"All Jacobian elements in the row are very small."
Using SBB solver, I don't know if this solver interferes with this equation.
I declared
POSITIVE VARIABLES ir;
ir.l = 0.0001;