问在循环中工作而不调用文件的quad函数

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    clear all;
clc;
%% All the constants and initial conditions

% the position conponents are "r" and "z"
% the velocity conponents are "vr" and "vz"

% the initial position components
rInitial= 10; %kpc
zInitial= 0; %kpc
% the initial velocity components
vrInitial= 0; %km/s
vzInitial= 150; %tangential velocity component
vtInitial= 150; %not used
% the height
h= rInitial*vzInitial; %angulan momentum constant
tInitial=0;
Dt=1e-3;
%ThetaiPlus1= Thetai + ( ( Dt*h ) / ( riPlus1Over2^2 ) );

%% The for loop

    % the position components
    riPlus1Over2= rInitial + 0.5*Dt*vrInitial;
    ziPlus1Over2= zInitial + 0.5*Dt*vzInitial;

    % integrating to solve for the acceleration components
    % needed for the integration
    b=0;
    e=0.99;
    pc=11613.5;
    AInitial= (1/e)*sqrt( ( rInitial^2*( sin(0) )^2 ) + ( zInitial^2*( tan(0) )^2 ) );
    aInitial=2.8;
    fe=asind(e); % the upper limit of th integral
    db= fe / 20; %4.094519277200290

    % solving for the accleration compoenet in the r diection
    KrInitialIntegratedPart= quad('(sin(x))*(exp(-AInitial/aInitial))*(db)', 0, fe)
    KrInitialFirstPart= -4*pi*pc*sqrt( 1-(e^2) / (e^3) )*rInitial;
    KrInitial= KrInitialFirstPart*KrInitialIntegratedPart;