Error : Constant Operands

13 views (last 30 days)
Life is Wonderful
Life is Wonderful on 23 Mar 2022
Edited: Life is Wonderful on 31 Mar 2022
Hi
Iam implementing following code as show below
m = 10;
v = [1 1 2 : m]
v = 1×11
1 1 2 3 4 5 6 7 8 9 10
If I try to make fixed point , I am getting the error "Operands must be constants." I don't understand what is expected here. Can someone help me ?
Thank you
  2 Comments
Geoff Hayes
Geoff Hayes on 23 Mar 2022
@Jogger - please clarify what you mean by "try to make this fixed point". What line of code leads to the error message?
Life is Wonderful
Life is Wonderful on 25 Mar 2022
try to make this fixed point - Sorry I didn't write my requirment clearly.
I mean m is a Embedded.fi object here . Let say m = 10 , then class of m is 'double' but when I use numerictype or fi, then m is translated to 'embedded.fi'.
The problem i see colon operator doesn't seems to work for 'embedded.fi'.

Sign in to comment.

Accepted Answer

David Hill
David Hill on 25 Mar 2022
Does changing to double work? I don't have the toolbox
v = [1 1 2 : double(m)]

More Answers (1)

Andy Bartlett
Andy Bartlett on 29 Mar 2022
I'm puzzled by the error you described "Operands must be constants.".
When I attempt to reproduce the issue, I don't observe any problem.
I created this simple function.
function y = makeVec(m)
y = [1 1 2 : m];
end
When I test this with double or fixed-point inputs
u1 = 10;
u2 = fi(10);
y1 = makeVec(u1)
y2 = makeVec(u2)
the outputs are as expected.
y1 =
1 1 2 3 4 5 6 7 8 9 10
y2 =
1 1 2 3 4 5 6 7 8 9 10
DataTypeMode: Fixed-point: binary point scaling
Signedness: Signed
WordLength: 16
FractionLength: 0
Code generation can provide additional restrictions, so I tried that too.
codegen makeVec -args {u1} -o makeVec1_mex
codegen makeVec -args {u2} -o makeVec2_mex
y1m = makeVec1_mex(u1)
y2m = makeVec2_mex(u2)
Again, the outputs were as expected.
y1m =
1 1 2 3 4 5 6 7 8 9 10
y2m =
1 1 2 3 4 5 6 7 8 9 10
DataTypeMode: Fixed-point: binary point scaling
Signedness: Signed
WordLength: 16
FractionLength: 0
If you could clarify the original reproduction steps, that would be appreciated.
Andy
  1 Comment
Life is Wonderful
Life is Wonderful on 29 Mar 2022
Edited: Life is Wonderful on 31 Mar 2022
The problem i see is coming from factorial function in matlab . Factorial function is unsupport by the fixed point designer . So I wrote my own implementation. I reliased the mistake in declaring fi Object and double togeather.

Sign in to comment.

Products


Release

R2021b

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!