I don't understand this error in Matlab 2021a: Error using slice (line 65) V must be a 3-D array.

I'm trying to simulate photon interaction on a Z-layered slab, my code is below:

cfg.shapes=('{"Shapes":[{"Grid":{"Tag":1,"Size":[60,60,60]}},{"ZLayers":[[1,5,2],[5,10,3],[10,20,4]]}');

cfg.prop=[0.0000, 0.0000, 1.0000, 1;

3.5640, 1.0000, 1.0000, 1.3700;

18.0543, 9.3985, 0.9000, 1.3700;

1.4000, 30.0000, 0.9000, 1.3700];

cfg.tstart=0;

cfg.tend=5e-9;

cfg.tstep=5e-10;

figure

% a pencil beam outside the volume

cfg.srctype='pencil';

cfg.srcpos=[30 30 -10];

flux=mcxlab(cfg);

fcw=flux.data*cfg.tstep;

hs=slice(log10(abs(double(fcw))),[],25,1);

Any help would be great thanks.

Answer 1

[Voss]

This error happens because fcw is not a 3-D array. You should inspect flux.data to see if it's what you expect.

[Fraser Eadie]

Thanks! It was a completely empty object.