This video shows how to create a proportional symbol map and legend using QGIS 3.x open source GIS software. Tutorial performed using QGIS 3.4. Skip to 5:48 for legend creation.
This is one of the most professional tutorials in the field. Great diction and pace; well prepared; no annoying 'out-takes'; very clear graphics. Excellentissimo!
Hi, Samara. Thanks for the video, it was incredebly helpful. I've been trying to create a legend for a proportional symbol flow map, but the option "Data defined size legend" doesn't seem to be available for linear shapefiles. Have you ever needed to deal with this issue? Thanks again! =)
Hello, I was wondering if it’s possible to make a collapsed legend, with graduated symbols? i.e. a collapsed legend that shows proportional sizing, mixed with a gradient of colors from light to dark depending on said size, if that makes any sense. Thanks!
Great video Samara! I wonder if you could provide a solution for a small issue. When i try to enter data-defined size legend there is an error that says "Data-defined size is not enabled". Have you ever encountered this issue?
Hi there Samara, ive been learning from your videos. In this particular Video at 3.51 when you selected the Symbol Input Source. On my side the input source does not show... am i missing something? Im using QGIS3
Hi there - are you sure that you have numeric fields in your source dataset? The fields won't show up in the Source dropdown list if they are text fields.
Thank you for the good video Samara. I am trying to draw this kind of map but it returns way too many circles in a single location. I think I have to change the specific field data to point data instead. The field in question is from a .csv file joined with the spatial layer. What should I do?
Very good instructions! thank you very much. If one needs to use both proportional symbol and graduate the colour of them based on another value of the same shp, how that can happen? Thanks again!
I have two polygons I'm trying to merge, 4 points on a top one with a line on the polygon below it. I keep getting "invalid" errors when I try to dissolve, and a general "error" message when I just try to merge them. I can't for the life of me figure out what's wrong. They are on the same layer, they have the same attributes (a number and a "year'). Help.
Samara: thank you so much for this video it has helped me very much. I am QGIS self taught/still a lot to learn. I am tasked with creating proportional symbol maps and the data points I have are plotted via LAT & LONG. having said that, when I got to marker assistant size the only sources to choose from are lat and long but I need volume data. are you able to assist, give me any pointers?
Hi Monica, I'm guessing that maybe your volume field is not a numeric field (double or integer) and that's why it doesn't show up. I have another tutorial video about how you can change the field type from text to a numeric type that might be helpful: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-y51CLkgkmX8.html
@@smebinger good morning. With your help, I was able to create my maps, but was wondering if there is a way to limit the symbol scheme legend and individually edit the sizes?
Hi Samara, Greetings ! I am wondering where can I download this data set that you are demonstrating on? I tried the WMATA web site but does not give me the numbers for the rider frequency.
Hi there - you can get the ridership data in tabular format through the National Capital Region Transportation Planning Board - I joined a cleaned up version of the table to a metro station shapefile but I notice they also have an API that might be an easier route if you're familiar with using APIs: rtdc-mwcog.opendata.arcgis.com/datasets/metro-rail-ridership-historical
