colorqgis
I have a txt file added like a layer to QGIS 3.4.2. File number 1. It is an attribute table.
I have a shapefile (a map) added to QGIS 3.4.2. This shapefile has all the countries of the world.
Both files are joined by a key field.
In the file number 1 I have a list of countries:
Key file – Name country – Color
1 – Canada – #000000
2 – US – #FFCC00
How can I change the background of all the countries of the map with the field "color" of every country?
You should not join tables together: it will cause multiplication of the same geometries (countries). Add a column to the .shp with countries and store number of people there. (But it seems that you should count numbers of people in other software - I don't see 'count' option in field calculator.) Then colourise your map using this field.
If the table with names and nationalities is constantly updated, then you should think about using spatial database for dynamical update of your map. You may store there table with countries and table with names and use view (that will count people and join this number with countries) to produce your map layer.
Well, not that easy, as QGIS does not come with predefined Robinson or Miller projections.
So I tried a Custom CRS and got this picture (not in first run!):
For a central meridian at 150° West, it is necessary to split the world boundaries shapefile at 30° East (to be precise, at 29.9 and 30.1 to avoid intersections)
So these are the steps:
Save As ... into WGS84, and add that to the canvasOn-the-fly-projectionNr;WKT
1;POLYGON((30.1 89, 29.9 89, 29.9 -89, 30.1 -89, 30.1 89))
Text delimited layer, using semicolon as separator and WGS84 as CRS (you will get a very thin polygon around 30°E)Vector -> Geoprocessing -> Difference with the two polygon layers+proj=robin +lon_0=-150 +x_0=0 +y_0=0 +ellps=WGS84 +datum=WGS84 +units=m +no_defs
On-the-fly projection and choose Robinson as project CRSFor the Miller projection, you can use the same pre-cut shapefile. In Proj, Miller has some problems with the ellipsoid, so we take a sphere instead (you won't see a difference):
+proj=mill +lon_0=-150 +lat_0=0 +R=6371000 +units=m +no_defs
With on-the fly activated, it does not look as well, New Zealand is missing at full extent, but returns when zooming in. So we need to Save As ... the shapefile in miller projection, and show only that, without on-the-fly reprojection:
Best Answer
Open
symbology tabof your layer and selectdata defined overrideatfill color, asfield typechooseyour color field.