float THD_pval_to_stat( float pval , int statcode , float * stataux )
{
float stat = -1.0 ; /* error flag */
if( pval >= 0.999999 ) return 0.0 ; /* WTF */
if( stataux == NULL && statcode != FUNC_ZT_TYPE ) return pval ;
switch( statcode ){ /* if statcode is illegal, will return -1 */
/** the routines below are in mri_stats.c **/
case FUNC_COR_TYPE:
stat = correl_p2t( pval , stataux[0] , stataux[1] , stataux[2] ) ;
break ;
case FUNC_TT_TYPE:
stat = student_p2t( pval , stataux[0] ) ;
break ;
case FUNC_FT_TYPE:
stat = fstat_p2t( pval , stataux[0] , stataux[1] ) ;
break ;
case FUNC_ZT_TYPE: /* only type that doesn't */
stat = normal_p2t( pval ) ; /* use stataux parameters */
break ;
case FUNC_CT_TYPE:
stat = chisq_p2t( pval , stataux[0] ) ;
break ;
case FUNC_BT_TYPE:
stat = beta_p2t( pval , stataux[0] , stataux[1] ) ;
break ;
case FUNC_BN_TYPE:
stat = binomial_p2t( pval , stataux[0] , stataux[1] ) ;
break ;
case FUNC_GT_TYPE:
stat = gamma_p2t( pval , stataux[0] , stataux[1] ) ;
break ;
case FUNC_PT_TYPE:
stat = poisson_p2t( pval , stataux[0] ) ;
break ;
}
return stat ;
}
void process_volume (float * ffim, int statcode, float * stataux)
{
int ixyz; /* voxel index */
int icount; /* count of sorted p-values */
float fval; /* voxel input statistical value */
float pval; /* voxel input stat. p-value */
float qval; /* voxel FDR q-value */
float zval; /* voxel FDR z-score */
float qval_min; /* smallest previous q-value */
voxel * head_voxel = NULL; /* linked list of voxels */
voxel * voxel_ptr = NULL; /* pointer to current voxel */
int ibin; /* p-value bin */
int * iarray = NULL; /* output array of voxel indices */
float * parray = NULL; /* output array of voxel p-values */
float * qarray = NULL; /* output array of voxel FDR q-values */
float * zarray = NULL; /* output array of voxel FDR z-scores */
float numer ;
/*------------ 18 Jan 2008: use the 'new' method? ------------*/
if( FDR_old < 1 ){
MRI_IMAGE *qim ; int flags=0 ;
qim = mri_new_vol_empty( FDR_nxyz,1,1 , MRI_float ) ;
mri_fix_data_pointer( ffim , qim ) ;
if( FDR_mask != NULL ){
float zz = (FUNC_IS_STAT(statcode)) ? 0.0f : 1.0f ;
for( ixyz=0 ; ixyz < FDR_nxyz ; ixyz++ )
if( !FDR_mask[ixyz] ) ffim[ixyz] = zz ;
}
if( FDR_curve ){ /* hidden option: produce t-z curve */
floatvec *fv = mri_fdr_curve( qim , statcode , stataux ) ;
if( fv == NULL ) ERROR_message("mri_fdr_curve fails!") ;
else {
printf("# FDR thresh-z curve\n") ;
for( ixyz=0 ; ixyz < fv->nar ; ixyz++ )
printf("%g %g\n", fv->x0+ixyz*fv->dx , fv->ar[ixyz] ) ;
}
exit(0) ;
} else { /* normal operation: convert to z(q) or q */
if( FDR_pmask == 0 ) flags |= 1 ; /* compatibility mode */
if( FDR_cn > 1.0f ) flags |= 2 ; /* dependency flag */
if( FDR_qval ) flags |= 4 ; /* qval flag */
(void)mri_fdrize( qim , statcode,stataux , flags ) ;
}
mri_clear_data_pointer(qim); mri_free(qim);
return ;
}
/*---------------- back to the 'old' method ------------------*/
/*----- Allocate memory for screen output arrays -----*/
if (FDR_list)
{
iarray = (int *) malloc (sizeof(int) * FDR_nthr); MTEST(iarray);
parray = (float *) malloc (sizeof(float) * FDR_nthr); MTEST(parray);
qarray = (float *) malloc (sizeof(float) * FDR_nthr); MTEST(qarray);
zarray = (float *) malloc (sizeof(float) * FDR_nthr); MTEST(zarray);
}
/*----- Loop over all voxels; sort p-values -----*/
icount = FDR_nthr;
for (ixyz = 0; ixyz < FDR_nxyz; ixyz++)
{
/*----- First, check if voxel is inside the mask -----*/
if( FDR_mask != NULL && !FDR_mask[ixyz] ) continue;
/*----- Convert stats to p-values -----*/
fval = fabs(ffim[ixyz]);
if (statcode <= 0)
pval = fval;
else
pval = THD_stat_to_pval (fval, statcode, stataux);
if (pval >= 1.0)
{
/*----- Count but don't sort voxels with p-value = 1 -----*/
icount--;
if (FDR_list)
{
iarray[icount] = ixyz;
parray[icount] = 1.0;
qarray[icount] = 1.0;
zarray[icount] = 0.0;
}
}
else
{
/*----- Place voxel in p-value bin -----*/
ibin = (int) (pval * (FDR_MAX_LL));
if (ibin < 0) ibin = 0;
if (ibin > FDR_MAX_LL-1) ibin = FDR_MAX_LL-1;
head_voxel = new_voxel (ixyz, pval, FDR_head_voxel[ibin]);
FDR_head_voxel[ibin] = head_voxel;
}
}
/*----- Calculate FDR q-values -----*/
qval_min = 1.0;
ibin = FDR_MAX_LL-1;
numer = (FDR_pmask) ? icount : FDR_nthr ; /* 18 Jan 2008 */
while (ibin >= 0)
{
voxel_ptr = FDR_head_voxel[ibin];
while (voxel_ptr != NULL)
{
/*----- Convert sorted p-values to FDR q-values -----*/
pval = voxel_ptr->pvalue;
qval = FDR_cn * (pval*numer) / icount;
if (qval > qval_min)
qval = qval_min;
else
qval_min = qval;
/*----- Convert FDR q-value to FDR z-score -----*/
if( !FDR_qval ){
if (qval < 1.0e-20) zval = 10.0;
else zval = normal_p2t(qval);
} else { zval = qval ; }
icount--;
/*----- Save calculated values -----*/
if (FDR_list)
{
iarray[icount] = voxel_ptr->ixyz;
parray[icount] = pval;
qarray[icount] = qval;
zarray[icount] = zval;
}
voxel_ptr->pvalue = zval;
voxel_ptr = voxel_ptr->next_voxel;
}
ibin--;
}
/*----- Write out the calculated values -----*/
if (FDR_list)
{
printf ("%12s %12s %12s %12s \n",
"Index", "p-value", "q-value", "z-score");
for (icount = 0; icount < FDR_nthr; icount++)
{
if (FDR_input1D_filename != NULL)
ixyz = iarray[icount] + 1;
else
ixyz = iarray[icount];
printf ("%12d %12.6f %12.6f %12.6f \n",
ixyz, parray[icount], qarray[icount], zarray[icount]);
}
/*----- Deallocate memory for output arrays -----*/
free (iarray); free (parray); free (qarray); free (zarray);
}
/*----- Place FDR z-scores into float array -----*/
save_all_voxels (ffim);
/*----- Deallocate linked-list memory -----*/
delete_all_voxels();
}
