When you add a metric to the graph, the default graph type is a column chart. This chart type can be changed as per your requirements to any type of graph.
Additionally, many further settings can be specified in order to customize each graph as per requirements. These settings (including the graph type) can then be saved into a “Graph Preset”, which means that the next time that the graph is displayed for the given metric(s), it will automatically load the graph preset.
Post your comment on this topic.