### Composite recalculation window

This dialog allows automatic calculation of number and volume of advancing/declining/unchanged
issues. Also possible in this dialog is calculation of volume numbers for indexes
if imported incorrectly. Note well, that automatic recalculation of composite
data makes only sense when you follow whole exchange (all symbols are included
in your database) otherwise this calculation will give wrong results.

In order to calculate the composites in the database it's necessary to set the base index for the market, as it may happen that not all stocks are quoted every businness day. AmiBroker checks the 'base index' quotations dates and tries to find the corresponding quotes of all the stocks belonging to that market, to find out how many issues advanced, declined and not changed at all.

To calculate composities you need to:

- Open Categories window using Symbol -> Categories menu item.
- Select base index for given market in Markets tab and Base indexes for - Composites combo.

For example if you are following NYSE this can by ^DJI (Dow Jones Average)
^DJI must be marked as index in Symbol -> Information and must belong to the same market.
- Choose "Symbol ->Calculate composites" menu item to open the window shown below and mark :
*Number of advancing/declining issues* and choose markets that you calculate composities for and the time range.
- Click Calculate.

There are also two additional fields available:

**Volume for base index**
**Copy volume to all indexes**

These fields are provided in case you DON'T have real volume data for index quotes. In that case AmiBroker can calculate volume for index as a sum of volumes of all stocks belonging to given market.
First option assigns calculated volume only to *base index*, the second copies the volume figure to all indices belonging to given market.