Input function must return 'double' or 'single' values. Found 'sym'.

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shahin hashemi 2020-4-7

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https://ww2.mathworks.cn/matlabcentral/answers/516195-input-function-must-return-double-or-single-values-found-sym

评论： Ameer Hamza 2020-4-8

采纳的回答： Ameer Hamza

在 MATLAB Online 中打开

dear all

when i using integral command although i define z i get the following error

clc
clear all
E2=10;
E1=20;
lE=E2/E1;
n=1;
h=2;
v1=30;
v2=40;
lv=v2/v1;
sym z
Eb=1+(((2*z+h)/2*h)^n)*(lE-1) 
vb=1+(((2*z+h)/2*h)^n)*(lv-1) 
fun=@(z) Eb/((1-(v1^2)*(vb^2))*h)
A11=integral(fun,-1/2,1/2)

and the error :

Undefined function or variable 'z'.
Error in first (line 13)
Eb=1+(((2*z+h)/2*h)^n)*(lE-1)

and also when i use syms z instead of sym z i get the following one :

fun =
  function_handle with value:
    @(z)Eb/((1-(v1^2)*(vb^2))*h)
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 first (line 18)
A11=integral(fun,-1/2,1/2)

i really appreciated if someone could help me with this

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采纳的回答

Ameer Hamza 2020-4-8

2
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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/516195-input-function-must-return-double-or-single-values-found-sym#answer_424727

在 MATLAB Online 中打开

Correct syntax is to use 'syms', not 'sym'. Also you should use matlabFunction to convert symbolic equation to numeric

clc
clear all
E2=10;
E1=20;
lE=E2/E1;
n=1;
h=2;
v1=30;
v2=40;
lv=v2/v1;
syms z
Eb=1+(((2*z+h)/2*h)^n)*(lE-1) 
vb=1+(((2*z+h)/2*h)^n)*(lv-1) 
fun= matlabFunction(Eb/((1-(v1^2)*(vb^2))*h))
A11=integral(fun,-1/2,1/2)