hi , i have problem with running the demo file in nifty_rec folder. when i running them this error display:
(i run et_demo_mlem.m )
??? Undefined function or method 'et_project_mex' for input arguments
of type 'double'.

Error in ==> et_project at 91
sinogram = et_project_mex(activity, cameras, attenuation, psf,
use_gpu, background, background_attenuation,
truncate_negative_values);

Error in ==> et_demo_mlem at 54
ideal_sinogram = et_project(phantom, cameras, attenuation, psf, GPU);
could anyone help me? what can i do to run them
my matlab is 2012 and my windows is 32 bit