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• you read the track points from the CSV file
• define a lotlat-lon box around each point
• read the forecast mean sea level data for the box for the corresponding time
• compute the minimum of the pressure in the box
• from these minimum values you can build the curve data to plot .
  
  

Create new Macro and edit it. First, read the CSV file in the very same way as before but this time on top of date and time you also need to Now read the date and time (from the first two columns) into separate latitude and longitude into vectors:

val_lat=values(tbl,3)
val_lon=values(tbl,4)

Next, you need to build the list of labels. Each label is made up from a day and an hour part separated by a slash. Use this loop to construct the list:iterate through the track points (i.e. using the val_date vector)

labels=nil

for i=1 to count(val_date) do
	labels = labels & ["   " & substring(string(val_date[i]),7,8) & "/" & val_time[i] ]
end for

or each point construct an area of e.g. 10 degrees wide centred on the the point. Then retrieve the data for the current step and area:

Finally, define a Symbol Plotting visual definition and return it.

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