Hi,

For example, if yours variable is H(A) the first element corresponds to H(‘a1’)

Bye

Hi

If you want a specific set element, you can also use the ord and card functions:

```
set
A/a1,a2/;
parameter h(a);
* first element
h("a1")
h(a)$(ord(a) = 1)
* second element
h("a2")
h(a)$(ord(a) = 2)
* last element
h(a)$(ord(a) eq card(a))
```

Cheers

Renger

Does GAMS not distinguish capital and lower letters?

True. It does not.

To “populate” a set:

```
set A /a1,a2/;
set B(A);
B(A)=YES$(ord(A)=2);
display B;
```

Hi Renger,

when I assign an element of a parameter to a scalar, error happens with “Uncontrolled set entered as constant” and “Set for ‘ord’ is not controlled”

Set A /a1,a2/;

parameter h(a) /a1*a2 2/;

scalar y /0/;

y=h(a)$(ord(a) = 1);

Could you please tell where the problem is? Thank you.

Best regards,

Yongning

Hi

y is defined as a scalar, so no index. If you write it like you did, Gams expects a set indicator also on the RHS. But this might not what you want, as you set the values for y for all other elements of a to zero:

```
parameter y(a);
y(a)$(ord(a) =1) = h(a);
display y(a)
```

You could keep y as a scalar and write the following

```
loop(a,
y = h(a)$(ord(a) = 1);
);
```

or

```
y = h("a1")
```

Hope this helps

Cheers

Renger