question: @ Override public void deleteColumns ( int start , int len ) throws FitsException { ensureData ( ) ; Object [ ] newData = new Object [ this . nFields - len ] ; int [ ] newOffsets = new int [ this . nFields - len ] ; int [ ] newLengths = new int [ this . nFields - len ] ; Class < ? > [ ] newTypes = new Class [ this . nFields - len ] ; String [ ] newNulls = new String [ this . nFields - len ] ; System . arraycopy ( this . data , 0 , newData , 0 , start ) ; System . arraycopy ( this . lengths , 0 , newLengths , 0 , start ) ; System . arraycopy ( this . types , 0 , newTypes , 0 , start ) ; System . arraycopy ( this . nulls , 0 , newNulls , 0 , start ) ; System . arraycopy ( this . data , start + len , newData , start , this . nFields - start - len ) ; System . arraycopy ( this . lengths , start + len , newLengths , start , this . nFields - start - len ) ; System . arraycopy ( this . types , start + len , newTypes , start , this . nFields - start - len ) ; System . arraycopy ( this . nulls , start + len , newNulls , start , this . nFields - start - len ) ; for ( int i = start ; i < start + len ; i += 1 ) { this . rowLen -= this . lengths [ i ] + 1 ; } this . data = newData ; this . offsets = newOffsets ; this . lengths = newLengths ; this . types = newTypes ; this . nulls = newNulls ; if ( this . isNull != null ) { boolean found = false ; boolean [ ] newIsNull = new boolean [ this . nRows * ( this . nFields - len ) ] ; for ( int i = 0 ; i < this . nRows ; i += 1 ) { int oldOff = this . nFields * i ; int newOff = ( this . nFields - len ) * i ; for ( int col = 0 ; col < start ; col += 1 ) { newIsNull [ newOff + col ] = this . isNull [ oldOff + col ] ; found = found || this . isNull [ oldOff + col ] ; } for ( int col = start + len ; col < this . nFields ; col += 1 ) { newIsNull [ newOff + col - len ] = this . isNull [ oldOff + col ] ; found = found || this . isNull [ oldOff + col ] ; } } if ( found ) { this . isNull = newIsNull ; } else { this . isNull = null ; } } this . buffer = null ; this . nFields -= len ; }
target:  Delete columns from the table.