I have faced a problem with data preparation for hub line(s) analysis in Qgis. I have searched for a whole day for the solution to my problem. There are a few topics related with that subject, although I haven’t found any detailed and useful information that would help me to solve my problem.
I’d like to visualize the network of air/train connections between cities in Europe. I have the vector layer containing 20k cities as points.
I prepared a csv. sheet in which I marked hub cities and other cities to which connections are established. The table looks like that:
I wanted to join that csv. table i.e. columns ‘hub id’ + ‘City_hub’ to the first copy of 20k cities layer.
Then columns “connected to” + “connected id” I’d like to join to the second copy of the20k cities layer.
However in that second layer, in the column: ‘connection id’ e.g. Berlin should have ‘1’, ‘2’ and ‘3’. How to do it where that particular column could store only one number?
I have seen a lot of images in the Internet f.e. http://michaelminn.com/linux/mmqgis/screenshots/mmqgis_hub_lines.png
This is the effect I’d like to achieve. The only solution that comes to my mind at the moment is that maybe should I copy and past ‘Berlin’ three times in the second layer? (but that method means a lot of work cause I cannot imagine how to automate it)
أكثر...
I’d like to visualize the network of air/train connections between cities in Europe. I have the vector layer containing 20k cities as points.
I prepared a csv. sheet in which I marked hub cities and other cities to which connections are established. The table looks like that:
I wanted to join that csv. table i.e. columns ‘hub id’ + ‘City_hub’ to the first copy of 20k cities layer.
Then columns “connected to” + “connected id” I’d like to join to the second copy of the20k cities layer.
However in that second layer, in the column: ‘connection id’ e.g. Berlin should have ‘1’, ‘2’ and ‘3’. How to do it where that particular column could store only one number?
I have seen a lot of images in the Internet f.e. http://michaelminn.com/linux/mmqgis/screenshots/mmqgis_hub_lines.png
This is the effect I’d like to achieve. The only solution that comes to my mind at the moment is that maybe should I copy and past ‘Berlin’ three times in the second layer? (but that method means a lot of work cause I cannot imagine how to automate it)
أكثر...