Bonferroni Step-down correction

//*********************************************************************
// statsBSDC
//
// Implements Bonferroni Step-down correction. 
//
// Parameters:
// w - input wave of p-values
// 
// Optional Parameters:
// ncol - column number of p-values if input wave w is a 2D matrix
//*********************************************************************
function statsBSDC(w,[ncol])

	//-----------------------------------------------------------------
	// parameters
	//-----------------------------------------------------------------
	wave w;
	variable ncol;
	
	//-----------------------------------------------------------------
	// variables
	//-----------------------------------------------------------------
	variable npnts,ndim;
	
	//-----------------------------------------------------------------
	// init variables
	//-----------------------------------------------------------------
	
	if(paramIsDefault(ncol))
		ncol = 0;
	endif
	
	npnts = dimsize(w,0);
	ndim = dimsize(w,1);

	//-----------------------------------------------------------------
	// main function
	//-----------------------------------------------------------------
	
	// copy p-values out to new wave and make index wave
	make/free/n=(npnts) wpv,wpi;
	
	if(ndim)
		wpv[] = w[p][ncol];
	else
		wpv[] = w[p];
	endif
	
	// populate index wave
	wpi[] = p;
	
	// sort from lowest to highest p-value
	sort wpv,wpv,wpi;
	
	// perform scaling correction
	wpv[] = wpv[p]*(npnts-p);
	
	// restore original sorting
	sort wpi,wpv,wpi;
	
	// copy adjusted p-values to original wave
	if(ndim)
		w[][ncol] = wpv[p];
	else
		w[] = wpv[p];
	endif

	// set p-values greater than 1 to 1
	w[] = w[p] > 1 ? 1 : w[p];

end