private void calculateAllChangesForInterval(float startDate,
			float[] startPrices, float[] endPrices) {
		float[] changes = new float[dbSet.size()];
		int errors = 0;
		for (int i = 0; i < dbSet.size(); i++) {
			if (endPrices[i] != endPrices[i]
					|| startPrices[i] != startPrices[i])
				errors++;
			// can be NaN for now
			if (startPrices[i] > 0)
				changes[i] = (endPrices[i] - startPrices[i]) / startPrices[i];
			else
				changes[i] = 0.0f / 0.0f;// NaN
			// changes[i] = (endPrices[i]/startPrices[i] ) -1 ;//alternate
			// method
		}

		// System.out.println("changes: 	" + Arrays.toString(changes));
		WEEKLY_MARKETCHANGE.put(startDate, averageMarketChange(changes));
		UNFORESEEN.put(startDate, changes);
	}