Error using Integral - IntegralCalc - Syms

2017 4 27
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更新时间：2017 4 27
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Hi, This is my Code
clc
clear all
syms Th
th1=5*pi/12 ;
th2=7*pi/12;
A11= @(Th) (10279222485063723*cos(Th).^2)/2684354560000 + (9*((7138348947960919*cos(Th).^2)/8589934592 + 1142135831673747/4294967296))/(625*cos(Th).^2)
A11Bar=integral(A11,th1,th2)
Acap =(10279222485063723*cos(Th).^2)/2684354560000 + (9*((7138348947960919*cos(Th).^2)/8589934592 + 1142135831673747/4294967296))/(625*cos(Th).^2)
Acap11 = @(Th) Acap
Acap11Bar=integral(Acap11,th1,th2)
I am trying to Integrate the Equation in A11 with limits th1 and th2. Using the Integral command, If I am using the equation directly it gives me the answer. But if Define the equation as Acap, Acap becomes symbolic and I dont get answer and the error comes as follows. My Question is , Th is a sym, but I get the answer for A11Bar, when using Th in A11, But why not the same in the other case.
A11 =
@(Th)(10279222485063723*cos(Th).^2)/2684354560000+(9*((7138348947960919*cos(Th).^2)/8589934592+1142135831673747/4294967296))/(625*cos(Th).^2)
A11Bar =
4.090565444758960e+04
Acap =
(2569805621265931*cos(Th)^2)/671088640000 + ((64245140531648271*cos(Th)^2)/8589934592 + 10279222485063723/4294967296)/(625*cos(Th)^2)
Acap11 =
@(Th)Acap
Error using integralCalc/finalInputChecks (line 511) Input function must return 'double' or 'single' values. Found 'sym'.
Error in integralCalc/iterateScalarValued (line 315) finalInputChecks(x,fx);
Error in integralCalc/vadapt (line 132) [q,errbnd] = iterateScalarValued(u,tinterval,pathlen);
Error in integralCalc (line 75) [q,errbnd] = vadapt(@AtoBInvTransform,interval);
Error in integral (line 88) Q = integralCalc(fun,a,b,opstruct);
Error in Untitled (line 13) Acap11Bar=integral(Acap11,th1,th2)

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 采纳的回答

Torsten
Torsten 2017-4-27

1 个投票

Use
Acap11 = matlabFunction(Acap)
Best wishes
Torsten.

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Hi Torsten, Thanks for your response, it did work, but there are few errors. Could you help on it as the answer varies.
A11 =
function_handle with value:
@(Th)(10279222485063723*cos(Th).^2)/2684354560000+(9*((7138348947960919*cos(Th).^2)/8589934592+1142135831673747/4294967296))/(625*cos(Th).^2)
A11Bar =
4.0906e+04
Acap =
(2569805621265931*cos(Th)^2)/671088640000 + ((64245140531648271*cos(Th)^2)/8589934592 + 10279222485063723/4294967296)/(625*cos(Th)^2)
Acap11 =
function_handle with value:
@(Th)cos(Th).^2.*3.829308779933946e3+1.0./cos(Th).^2.*(cos(Th).^2.*7.479118710808487e6+2.393317987458716e6).*(1.0./6.25e2)
Warning: Minimum step size reached near x = 1.5708. There may be a singularity, or the tolerances may be too tight for this problem. > In integralCalc/checkSpacing (line 456) In integralCalc/iterateScalarValued (line 319) In integralCalc/vadapt (line 132) In integralCalc (line 75) In integral (line 88) In Untitled (line 12)
Acap11Bar =
1.9726e+17
Torsten
Torsten 2017-4-27
编辑：Torsten 2017-4-27
cos(Th) = 0 at Th=pi/2, so you divide by 0.
Best wishes
Torsten.
Hi Torsten,
But if you check in my program given above, I have set the limits from 75 degrees to 105 degrees. I have not used 90 degrees ( pi/2 ) .
clc
clear all
syms Th
th1=5*pi/12 ;
th2=7*pi/12;
A11= @(Th) (10279222485063723*cos(Th).^2)/2684354560000 + (9*((7138348947960919*cos(Th).^2)/8589934592 + 1142135831673747/4294967296))/(625*cos(Th).^2)
A11Bar=integral(A11,th1,th2)
Acap =(10279222485063723*cos(Th).^2)/2684354560000 + (9*((7138348947960919*cos(Th).^2)/8589934592 + 1142135831673747/4294967296))/(625*cos(Th).^2) Acap11 = matlabFunction(Acap) Acap11BarA=integral(Acap11,th1,th2)
A11 =
function_handle with value:
@(Th)(10279222485063723*cos(Th).^2)/2684354560000+(9*((7138348947960919*cos(Th).^2)/8589934592+1142135831673747/4294967296))/(625*cos(Th).^2)
A11Bar =
4.6631e+04
Acap =
(2569805621265931*cos(Th)^2)/671088640000 + ((64245140531648271*cos(Th)^2)/8589934592 + 10279222485063723/4294967296)/(625*cos(Th)^2)
Acap11 =
function_handle with value:
@(Th)cos(Th).^2.*3.829308779933946e3+1.0./cos(Th).^2.*(cos(Th).^2.*7.479118710808487e6+2.393317987458716e6).*(1.0./6.25e2)
Warning: Minimum step size reached near x = 1.5708. There may be a singularity, or the tolerances may be too tight for this problem. > In integralCalc/checkSpacing (line 456) In integralCalc/iterateScalarValued (line 319) In integralCalc/vadapt (line 132) In integralCalc (line 75) In integral (line 88) In Untitled (line 12)
Acap11BarA =
1.1694e+18
Torsten
Torsten 2017-4-27
编辑：Torsten 2017-4-27
90° is in between 75° and 105°, and you integrate over the entire interval.
Note that x=1.5708 is approximately pi/2.
Best wishes
Torsten.

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