Error using sum Invalid data type. First argument must be numeric or logical.

Hi everybody.

I try to make integration over the variable q for the expression with inside integration and summation and find the answer in the form of the numerical value. Here my simple code

function z=self_energy_summation

k=1;
w=10;

z1=load('test.txt');

tt=z1(741,1);
T_c=z1(741,2);
mu=z1(741,3);

N=1:10;
nn=10^4;

fun1=@(a,q) a.*tanh((a.^2-mu)./(2*T_c)).*log((2*a.^2+2*a.*q+q.^2-2*mu-1i*2*pi.*N(1:10).*T_c)./(2*a.^2-2*a.*q+q.^2-2*mu-1i*2*pi.*N(1:10).*T_c))./q-2;
Gamma0=@(q) tt+integral(@(a)fun1(a,q),0,nn,'ArrayValued',true);
fun2=@(q) k*w*Gamma0./q.^3;

R=@(q) sum(fun2);

y=integral(@(q) R(q),0.001,nn,'ArrayValued',true)

end

Before the last integration I get the error

"Error using sum Invalid data type. First argument must be numeric or logical."

If I execute my script without last integration then the program works correctly.

Could you help me?

Answer 1

[Walter Roberson]

R=@(q) sum(fun2(q));

[Yuriy Yerin]

Thank you. But after this correction I still have the same error.

[Guillaume]

But after this correction I still have the same error

Very doubtful. You may get an error but it shouldn't be the exact same error. What is the error you now get?

[Yuriy Yerin]

I apologize. I provided incorrect information. Anyway I have an error

Undefined operator '*' for input arguments of type 'function_handle'.

Error in self_energy_summation>@(q)k*w*Gamma0./q.^3 (line 12) fun2=@(q) k*w*Gamma0./q.^3;

Error in self_energy_summation>@(q)sum(fun2(q)) (line 13) R=@(q) sum(fun2(q));

Error in self_energy_summation>@(q)R(q) (line 14) y=integral(@(q) R(q),0.001,nn,'ArrayValued',true)

Error in integralCalc/iterateArrayValued (line 156) fxj = FUN(t(1)).*w(1);

Error in integralCalc/vadapt (line 130) [q,errbnd] = iterateArrayValued(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 self_energy_summation_test (line 14) y=integral(@(q) R(q),0.001,nn,'ArrayValued',true)

[Guillaume]

fun2 = @(q) k*w*gamma0(q)./q.^3;

possibly, assuming gamma0 is supposed to use q as input.

[Steven Lord]

You cannot perform arithmetic operations on function handles, nor can you sum them. Instead perform arithmetic or call sum on the values returned by evaluating the function handle.

f = @(x) x.^2;
g1 = 2*f(1:10) % works
g2 = 2*f % does not work