how to use integral function

i have problem where i need to use integral but it must be function handle.

here my coding

freq_n_1 = 0
freq_n = max (freq)
b = 1./(freq_n-freq_n_1).*(integral(y_amp_transpose,freq_n_1,freq_n));

where my y_amp_transpose in matrix

how can i use this equation

[Torsten]

Use "trapz" instead of "integral" :

dt = ...;
t = frq_n_1:dt:freq_n;
summe = trapz(t,y_amp_transpose)