help, pls how can i convert from syms to double

1 Ansicht (letzte 30 Tage)
abdulwahab ibrahim
abdulwahab ibrahim am 16 Mär. 2016
Kommentiert: Javier Bastante am 28 Mär. 2016
clc
clear all
syms s
Kw= 0.05;Ka=0.01;
T=0.1; R=500;
f=50; L=2500*10^-6;
X=2*pi*f*L;
d0_1=-0.019; d0_2=0.019; dw1=0.5; dw2=-0.5; dV1=0; dV2=0;
dPavg1=-10; dPavg2=10; dQavg1=0; dQavg2=0;
M=4*X + X^3/R^2;
t=(0:0.2:2)
V1eq=23;
V2eq=23;
O1eq=0.019;
O2eq=-0.019;
a1=(2*X*V1eq/R + 2*V2eq*sin(O1eq - O2eq) + X*V2eq/R*cos(O1eq - O2eq))/4*X + X^3/R^2;
b1=(2*V1eq*sin(O1eq - O2eq) + (X/R)*V1eq*cos(O1eq - O2eq))/M;
c1=(2*V1eq*V2eq*cos(O1eq - O2eq) - (X/R)*V1eq*V2eq*sin(O1eq - O2eq))/M;
d1=-c1;
a2=(2*V2eq*sin(O2eq - O1eq) + (X/R)*V2eq*cos(O2eq - O1eq))/M;
b2=(2*V2eq*X/R + 2*V1eq*sin(O2eq - O1eq) + V1eq*(X/R)*cos(O2eq -O1eq))/M;
c2=(-2*V1eq*V2eq*cos(O2eq - O1eq) + (X/R)*V1eq*V2eq*sin(O2eq - O1eq))/M;
d2= -c2;
a3=(2*(X^2/R^2 + 2)*V1eq - 2*V2eq*cos(O1eq - O2eq) + X/R*V2eq*sin(O1eq - O2eq))/M;
b3=(-2*V1eq*cos(O1eq - O2eq) + X/R*V1eq*sin(O1eq - O2eq))/M;
c3=(2*V1eq*V2eq*sin(O1eq - O2eq) + X/R*V1eq*V2eq*cos(O1eq - O2eq))/M;
d3= -c3;
a4= (-2*V2eq*cos(O2eq - O1eq) + (X/R)*V2eq*sin(O2eq - O1eq));
b4=(2*(2+X^2/R^2)*V2eq - 2*V1eq*cos(O2eq - O1eq) + X/R * V1eq*sin(O2eq - O1eq))/M;
c4=(-2*V1eq*V2eq*sin(O2eq - O1eq) - X/R*V1eq*V2eq*cos(O2eq - O1eq));
d4=-c4;
X1=[d0_1; d0_2; dw1; dw2; dV1; dV2; dPavg1; dPavg2; dQavg1; dQavg2];
A1=[0 1 0 0 0 0 0 0 0 0;
0 0 0 1 0 0 0 0 0 0;
(-Kw*c1)/T (-Kw*d1)/T -1/T 0 (-Kw*a1)/T (-Kw*b1)/T 0 0 0 0;
(-Kw*c2)/T (-Kw*d2)/T 0 -1/T (-Kw*a2)/T (-Kw*b2)/T 0 0 0 0;
(-Ka*c3)/T (-Ka*d3/T) 0 0 (1+Ka*a3)/T (-Ka*b3/T) 0 0 0 0;
(-Ka*c4)/T (-Ka*d4)/T 0 0 (-Ka*a4)/T -(1+Ka*b4)/T 0 0 0 0;
c1/T d1/T 0 0 a1/T b1/T -1/T 0 0 0;
c2/T d2/T 0 0 a2/T b2/T 0 -1/T 0 0;
c3/T d3/T 0 0 a3/T b3/T 0 0 -1/T 0;
c4/T d4/T 0 0 a4/T b4/T 0 0 0 -1/T]
sX1=A1*X1
plot(t,dPavg1)
  3 Kommentare
Ced
Ced am 16 Mär. 2016
You are defining a symbolic variable s, but I cannot see you using it anywhere?
Walter Roberson
Walter Roberson am 16 Mär. 2016
Note that your dPavg1 is just the scalar value -10 so you would have trouble seeing your plot.

Melden Sie sich an, um zu kommentieren.

Akzeptierte Antwort

Javier Bastante
Javier Bastante am 16 Mär. 2016
Bearbeitet: Javier Bastante am 28 Mär. 2016
It's true that you haven't used s but the answer to your question is as easy as this:
>> syms s
>> number=s+s-3/4 %The result will be 3/4 as symbolic
>> number2=double(number) %Now the result is 0.7500
So, the function is double(var)
Hope it's useful. Regards
  1 Kommentar
Javier Bastante
Javier Bastante am 28 Mär. 2016
I wrote syms x instead of syms s. Sorry about that. It's already been corrected

Melden Sie sich an, um zu kommentieren.

Weitere Antworten (0)

Tags

Community Treasure Hunt

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

Start Hunting!

Translated by