5.7 Density Map
Level of expertise required for this Chapter: Advanced; general Map Maker training
You have points and want to produce a density map. For example, you know all clinics and want to produce a map with the intensity of clinic pattern.
1. Create point DRA file
Most likely, you already have a point DRA file, or you convert a LOC file to a DRA file.
2. Create a DTM (TER file)
Utilities > 3D surface utilities > Create surface > Density surface from spot values
> Select DRA file of step 1 > Density surface window: Accept all as proposed > OK
> 'Save as' window to save as TER file > Enter new name > Save
3) Produce contour (DRA line) file (if required)
Utilities > 3D surface utilities > Export surface > As contours
> Step 1: 'Choose source TER file' and select from 2) above > Next step
> Step 2: Select highest possible (10) > The ..... should be somewhere between the min and the max z (in this example: Z is between 1 and 7: Good entry is 1)
> Step 3: 'Choose target file' > Enter new name for the new DRA line file > Finish > Confirm save
4) Produce contour (DRA line) file (if required)
Polygons are based on the DRA line file, created in the previous step:
Utilities > Vector utilities > Actions > Select DRA line file from previous operation > Polygon manipulation > Convert lines to polygons > OK >
Convert lines to polygons' window: Accept all as proposed > OK > 'Save as' window: Enter new name for this new DRA polygon file.
You might have to do some editing of the styles to get the right colors.
5) Produce raster (JPG or similar) file as background (if required)
Utilities > 3D surface utilities > Create bitmap > Altitude > Select TER file created in step 2 > Open > Settings: Pixels per cell: 10 >
Colours > by Bands > Define your favourite. In most cases a dark-light pattern fits best, i.e at Top colour, define a dark gray, in Bottom colours, define a light gray:
OK > Ok > 'Save as' window to save as JPG (or BMP) file > Enter new name > Save > Map Maker calibration > OK