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CombineTableWorkspaces v1¶

Summary ¶

Algorithm takes two table workspaces and, if they have the same column titles and data types, combines them into a single table. Currently supports data types of double, int, float, string, bool, size_t and V3D.

Properties ¶

Name	Direction	Type	Default	Description
LHSWorkspace	Input	TableWorkspace	Mandatory	The first table workspace.
RHSWorkspace	Input	TableWorkspace	Mandatory	The second table workspace.
OutputWorkspace	Output	TableWorkspace	Mandatory	The combined table workspace.

Description ¶

This algorithm can be used to combine a pair of Table Workspaces into a single table. The current algorithm is very lightweight and is intended for situations where multiple tables are produced by the same processing pipeline, but ultimately the output of all the generated data in a single table would suffice. As such, the algorithm requires that the Column names match exactly, are in the exact same order and that corresponding columns have identical data types.

The currently supported data types are double, int, bool, float, string, size_t, and V3D.

Example Usage ¶

Here we have a python function to generate us some example table workspaces:

def create_example_table(table_name, data_types, column_names, n_rows, data):
    """
    table_name: name for output workspace
    data_types: collection of strings of data types, one for each column
    column_names: collection of strings of column names, one for each column
    n_rows: number of rows in table
    data: collection of collection of values for each row, if only one is specified it will be
          reused for all rows
    """
    table = CreateEmptyTableWorkspace(OutputWorkspace = table_name)
    for i, dt in enumerate(data_types):
        table.addColumn(dt, column_names[i])
    for r in range(n_rows):
        if len(data) == 1:
            table.addRow(data[0])
        else:
            table.addRow(data[r])

# here is an example table with two columns, labelled 1 and 2, with 2 rows each, both taking integer values
create_example_table("test_table1", ["int", "int"], ["1", "2"], 2, ([0,1],[2,3]))

We can use this helper function to demonstrate the algorithm usage:

create_example_table("test_table1", ["int", "int"], ["1", "2"], 2, ([0,1],[2,3]))
create_example_table("test_table2", ["int", "int"], ["1", "2"], 2, ([4,5],[6,7]))

CombineTableWorkspaces("test_table1", "test_table2", OutputWorkspace = "comb1")

This also works for tables with mixed data types

create_example_table("test_table3", ["str", "bool", "int"], ["1", "2", "3"],
                 50, (["a", True, 1],))

CombineTableWorkspaces("test_table3", "test_table3", OutputWorkspace = "comb2")