when I change the spacing in linspace, that change my plot values drasticaly

this is part of my code

syms x;
 w=symfun(2*pi*x,x); 
%%%%%% 
f = linspace(10,500,490);
%Electrico
 Lvc=0.00145;
 Rvc=5.5;
 Red=3.9;
 
 %Mecanico
 Mmasa=9.74999*(10^-2);
 Rm=58.1;
 Fo=40;
  %Constantes
 BL=19.2;
 Dspeaker=0.335;
 
 %parametros
 Fmin=10;
 Fmax=500;
 
  RadioSpeaker=Dspeaker/2;
 AreaSpeaker=(RadioSpeaker^2)*pi;


 Girador=BL^2;
 TransGirador=Girador/((AreaSpeaker)^2);
 
 Cm=(((2*pi*Fo)^2)*Mmasa)^-1;
 
 %I0
Ibobina=1i*w*Lvc;
I0=(((Ibobina^-1)+(Rvc^-1))^-1)+Red;

%I1
Imasa=Girador*((1i*w*Mmasa)^-1);
IRmecanico=Girador/Rm;
Icompliancia=Girador*1i*w*Cm;

I1=((Imasa^-1)+(IRmecanico^-1)+(Icompliancia^-1))^-1;

%%%
Ielectrica=abs(I0+I1);%I0 and I1 depends of w
IelectricaPLOT=Ielectrica(f);
plot(IelectricaPLOT);
set(gca, 'XScale', 'log')

and with f = linspace(10,500,1000);

[Matt J]

Provide us enough code and input data to reproduce it.

[Vitto Torres]

done

Answer 1

[Image Analyst]

The signal value is the same, 10.28, but since you're plotting the x as the index, not some actual x value, the x value will of course change because you are changing the number of indexes. That's why you get 31 one time and 61 the next time. Makes perfect sense, don't you think?

If you don't want that, plot(x,y) instead of just plot(y) which will assume x as the index of the vector.