Use the Controls to set the frequency range. I don't think there is anything that explicitly shows a single value on the chart, but you can roll your own by taking input from an HTML form field (or something similar) and searching the DataTable for the frequency using the DataTable#getFilteredRows() method (which will return the rows matching the filter) and fetching the associated strength by calling the DataTable#getValue() method.
I can't help you much with getting data from the radio - you'll have to work that out for yourself. I presume this will involve some server-side processing to pull data from the radio, which you can then pass to the client via PHP scripting or AJAX calls to a server script. -- You received this message because you are subscribed to the Google Groups "Google Visualization API" group. To view this discussion on the web visit https://groups.google.com/d/msg/google-visualization-api/-/NuHoyEw4498J. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-visualization-api?hl=en.
