How to I create the average of spectra in a hypercube?

Hello!

Ive captured the hypercubes for white reference,dark reference and object as part of normalisation and getting the object reflectance of a SpecIm hyperspectral camera.

Ive read the data using multibandread.How do I -

1. First using the cube of white ref, create an average spectra and obtain a vector white_ref[i], i = 1 to all wavelengths

2. Using the cube dark ref (taken at integration time of white reference), create an average spectra across one line and obtain a matrix : dark_ref_white[i, j], i=1 to all points along a line perpendicular to scan direction. j = 1 to all wavelengths

3. Using the cube dark ref(taken at integration time set for objects), create an average spectra and obtain a matrix : dark_ref_object[i,j], i=1 to all points along a line perpendicular to scan direction. j = 1 to all wavelengths

Its only after I can do this, can I implement the formula to get reflectance :

Object_reflectance [i,j,k] = ( ( object_captured [i,j,k] - dark_ref_object[j,k] )*tint_white_ref ) / ( ( white_ref[j,k] – dark_ref_white[j,k])*tint_object)

where tint = integration time( i have this from the header files,so no problem)

Thank You