Error reading .mrc file

I am using the ReadMRC function that @Fred Sigworth provided Imagic, MRC and DM3 file i/o

However, when I try opening a file using

ReadMRC(sample.mrc)

I always get the error

Undefined variable "sample" or class "sample.mrc"

I can't seem to find what I am doing wrong. I am using version R2017a on Linux

Answer 1

[José-Luis]

 ReadMRC('sample.mrc')

[Anand Dwivedi]

Thanks!Is there a way to display the 3d model as well?

[yin zhen]

Rchannel = map(:,:,1);
Gchannel = map(:,:,2);
Bchannel = map(:,:,3);
figure;
scatter3(Rchannel(:),Gchannel(:),Bchannel(:));