meaning of parameters in classification

[zazuo]

Hi, I have read code in classification and I got some problems:

1. line 68-69 in classification.c

    mat = Mat_Open("/data1/sguo/CCDC/classification/Xs.mat",MAT_ACC_RDONLY);
    mat2 = Mat_Open("/data1/sguo/CCDC/classification/Ys.mat",MAT_ACC_RDONLY);

I'm not quite sure about the input files Xs.mat and Ys.mat. I think they might be the samples(Xs.mat) and labels(Ys.mat), but I dont know the structure of these files. And is Xs.mat created with the result of CCDC? Can you give me an example or demo files?

2.I am confused with the meaning of virable ref_x and x.

classRF(ref_x, dimx, y, &nclass, cat, &maxcat,
	     &sampsize, &strata, Options, &ntree, &mtry,&ipi, 
         classwt, cutoff, &nodesize,outcl, counttr, &prox,
	     impout, &impSD, &impmat, &nrnodes,ndbigtree, nodestatus, 
         bestvar, treemap,nodepred, xbestsplit, errtr,&testdat, 
         &xts, &clts, &nts, countts,&outclts, labelts, 
         &proxts, &errts,inbag,0);

Here I see the used of ref_x in line 208, but I can't find the initailization of it. So what's this virable for and is it part of x?

Looking forward for your reply.