Embedded Function Error-algebraic loop error message in Simulink

Hi,Help please,when i try to run my Simulink model, i obtain this error:

Cannot solve algebraic loop involving 'Nussbaum/Switch' because it consists of blocks that cannot be assigned algebraic variables, i.e., blocks with discrete-valued outputs, blocks with non-double or complex outputs, Stateflow blocks, or nonvirtual subsystems

Answer 1

[Kaustubha Govind]

Do you have an output connect as an input (in a loop)? Perhaps you might want to avoid the algebraic loop in the first place so that Simulink doesn't have to solve it. Please see What are algebraic loops in Simulink and how do I solve them? and this blog post: http://blogs.mathworks.com/seth/2008/07/03/how-did-i-get-an-algebraic-loop-error-when-the-diagnostic-was-set-to-warning/

Also, this previously answered question has a lot of good tips: http://www.mathworks.com/matlabcentral/answers/34478-is-this-the-way-to-solve-algebraic-loops

[iman]

Dear Kaustubha,

thank you for your help so very much!!!

I solved my problem related to this error,but in this simulink model i use another Embedded MATLAB block and i have a new error as following:

Output argument 'sn1' is not assigned on some execution paths.

Code generation failed Errors occurred during parsing of MATLAB function 'Nussbaum/Nussbaum4'

Errors occurred during parsing of MATLAB function 'Nussbaum/Nussbaum4'

this is my code in embedded:

function sn1 = fcn(xs,sn,SN)

%eml

sn = sign(sn);

if sn == +1

if SN <= xs^1.5, sn1 = 1;

elseif SN > xs^1.5, sn1 = -1; end

elseif sn == -1

if SN < -xs^1.5, sn1 = 1;

elseif SN >= -xs^1.5, sn1 = -1; end

else

sn1=1;

end

Please Help me!!!

[Kaustubha Govind]

Iman: Ideally, you should post this as a new question, but I'll try and answer it anyway. I think you need to "pre-allocate" sn1. Just add something like "sn1=0" before the if block.