Originally posted by: skyskyhuanghuang

Hi,everyone:

   I encountered a problem. When defining the decision variables, I wrote the following form

//using CP;
int M=2;
float H[1..M][1..M]=...;
float B0=...;
float n0=...;

dvar float+ PVariety[1..M];

maximize
PVariety[1]*H[1][1]*H[1][1]/
  (n0+H[2][2]*H[2][2]*PVariety[2]);
subject to
{
forall(i in 1..M)
0<=PVariety[i]<=0.251;
sum(i in 1..M)PVariety[i]<=0.502;                                                                                         
}

But it's wrong, how do I define the float decision variable？

Hi,

since you divide by PVariety this model is not linear. I d rather use CPO:

.mod

using CP;

int scale=100000;
int M=2;
float H[1..M][1..M]=...;
float B0=...;
float n0=...;

dvar int+ scalePVariety[1..M] in 0..10*scale;

dexpr float PVariety[i in 1..M]=scalePVariety[i]/scale;

maximize
PVariety[1]*H[1][1]*H[1][1]/
  (n0+H[2][2]*H[2][2]*PVariety[2]);
 
 
subject to
{
forall(i in 1..M)
0<=PVariety[i]<=0.251;
sum(i in 1..M)PVariety[i]<=0.502;                                                                                         
}

.dat

H=[[5 6.1][1 2]];
B0=1.2;
n0=1.3;

works fine

regards

Originally posted by: skyskyhuanghuang

thank you