Loading data into a da_datastore - 5.2 English - 68552

Data can be loaded into a da_datastore by adding blocks of data from different sources. A typical example is to load data from a file and add columns that were allocated dynamically in your program. This can be achieved by calling da_data_load_from_csv() and da_data_load_col_int() consecutively, for example.

When calling any of the da_data_load_row_? or da_data_load_col_? functions on a da_datastore that is not empty, certain constraints must be respected.

• While adding columns, the number of rows in the block to be added must match the current number of rows present in the da_datastore (da_data_get_num_rows() can be used to query the dimension).

• New rows can be added in several sub-blocks. However:

  • the da_datastore will be locked until the current number of columns in the store matches the number of columns of the new block;

  • each sub-block has a minimum column size determined by the number of consecutive columns of the same type in the store. For example, if a given store already has two integer columns and a float column, new rows can be added in two sub-blocks (one with two integer columns and one with the remaining float column).

The final way to load data into a data store is from another da_datastore. Calling da_data_hconcat() will horizontally concatenate two da_datastore objects with matching numbers of rows.