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Info |
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This exercise involves:
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Preparations
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- set the plot type to geo points
- select the columns holding the latitude and longitude by their index
- carefully specify the table delimiter and header information by setting
- table_delimiter to whitespace (enter a space character here)
- table_combine_delimiters to on
- table header_row to 0
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To finalise the track plot you need to add the date/time labels to the track points. This can be done with a Symbol Plotting icon by specifying the list of labels you want to plot into the map. Since it would require too much editing you will learn a better (programmatic) way of doing it by using Metview Macro.
Create a new Macro and edit it. First, read the CSV file in with the Table Reader:
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Code Block |
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labels=nil for i=1 to count(val_date) do labels = labels & ["dPart = " & substring(string(val_date[i]),7,8) & "/"tPart &= val_time[i] label = " " & dPart & "/" & tPart labels = labels & [label] end for |
Finally, define a Symbol Plotting visual definition and return it.
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- the x-axis type to date
- the x axis minimum to 2012-10-27 and its maximum to 2012-10-31
- the y-axis label to hPa
- the y-axis minimum value to 940 and its maximum is to 1000
Computing the minimum pressure along the track
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Next, compute the minimum of the field you read in the subarea using the minval()
macro function:
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Code Block |
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vis = input_visualiser ( input_x_type : "date", input_date_x_values : trDate, input_y_values : trVal ) return [vis] |
By returning the visual definition visualiser you built a Macro that behaves as if it were an Input Visualiser icon. Now visualise your Cartesian View icon and drag your Macro into it.
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Creating a title
Define a custom title to as shown in the example plot with a new Text Plotting icon.
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With a new Display Window icon design an A4 portrait layout with two views: your Geographical View icon should go top and your Cartesian View icon into the bottom. Now visualise your icon and populate the view views with the data.
Extra Work
Try the following if you have time.
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