Matlab error: The expression to the left of the equals sign is not a valid target for an assignment

Hi! I'm a beginner and i'm trying to run this code in matlab

plot2d([0:1:itermax]',[Tfixe' Topt' Trand'],logflag = 'nl'; style=[1 2 3]);

xtitle('','k','||xk-x||')

legends(['pas fixe';'pas optimal';'randomis'],[1 2 3],opt='ll')

but when i do run it , this error comes out : The expression to the left of the equals sign is not a valid target for an assignment.

can you help mefind the solution ? thank you!

[madhan ravi]

You need to explain what that code does.