Error: File: centraldiff.m Line: 1 Column: 11 Unbalanced or unexpected parenthesis or bracket

function[U(m+1)]=centraldiff(Tn,zeta,U(1),U(2),acc(m),dt)

%Tn=2*pi*sqrt(m/k)

%U(1)=0; % displacement at point t=0 of SDOF

%V(1)=0; % velocity at point t=0 of SDOF

%zeta=0.05;

%Tn=2.5

%U(2)=0;

for m=2:20;

U(m+1)=-acc(m)/(1/dt^2+2*pi*zeta/Tn*dt)+((-1/dt^2+2*pi*zeta/Tn*dt)/(1/dt^2+2*pi*zeta/Tn*dt))*U(m-1)+((-4*pi^2/Tn^2+2/dt^2)/(1/dt^2+2*pi*zeta/Tn*dt))*U(m)

end

[TT]

when evaluating function it gives Error: File: centraldiff.m Line: 1 Column: 11 Unbalanced or unexpected parenthesis or bracket. What is the error

Answer 1

[Steven Lord]

When you define your function, the function declaration line should include the names of the variables into which the input arguments will be stored. It cannot contain expressions like U(1) or U(m+1).

When you call your function, specify the exact values on which you want your function to operate. The call can contain expressions.

This is an incorrect way to define the addme function:

function z = addme(2, 3)
z = 2+3;
end

This is a correct way to define the addme function:

function z = addme(x, y)
z = x + y;
end

and these are correct ways to call the addme function.

theOutput(17) = addme(2, 3)
theOutput(2) = addme(pi^2, sind(45))

See this documentation page for more information on defining functions.