help, pls how can i convert from syms to double

조회 수: 1 (최근 30일)
abdulwahab ibrahim
abdulwahab ibrahim 2016년 3월 16일
댓글: Javier Bastante 2016년 3월 28일
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)
  댓글 수: 3
Ced
Ced 2016년 3월 16일
You are defining a symbolic variable s, but I cannot see you using it anywhere?
Walter Roberson
Walter Roberson 2016년 3월 16일
Note that your dPavg1 is just the scalar value -10 so you would have trouble seeing your plot.

댓글을 달려면 로그인하십시오.

채택된 답변

Javier Bastante
Javier Bastante 2016년 3월 16일
편집: Javier Bastante 2016년 3월 28일
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
  댓글 수: 1
Javier Bastante
Javier Bastante 2016년 3월 28일
I wrote syms x instead of syms s. Sorry about that. It's already been corrected

댓글을 달려면 로그인하십시오.

추가 답변 (0개)

카테고리

Help CenterFile Exchange에서 Assumptions에 대해 자세히 알아보기

태그

Community Treasure Hunt

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

Start Hunting!

Translated by