<｜begin▁of▁sentence｜>### Instruction:
Given a graph which you can read from graph_data.gml, can you determine the indices of vertices that are in the same component as a given vertex, say vertex 0, considering all the connections? The graph can be either directed or undirected.
### Response:
```python
from igraph import Graph
import igraph as ig

# Read the graph from the file
graph = ig.read('graph_data.gml')

# Choose a vertex index, for example, vertex 0
vertex_index = 0

# Get the subcomponent that includes the chosen vertex
subcomponent_vertices = graph.subcomponent(vertex_index, mode='ALL')

# Print the indices of the vertices in the subcomponent
print(subcomponent_vertices)
```
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