QGIS Atlas – Set Scale and Scale Bar to Round Number

atlasqgisscale bar

My AOI table looks like

I have the following settings in the map frame.

Notice the scale is not a round value.

I have tried to change the value for 'Margin around feature' to 0 but this doesn't change it. The AOI polygons are set to be exactly 1:10k, 5k, 2.5k

I have also tried to set the properties–>view settings to these values and also the override to be "Scale"

I was expecting functionality similar to Data Driven Pages in ArcMap – https://desktop.arcgis.com/en/arcmap/10.3/map/page-layouts/creating-data-driven-pages.htm#ESRI_SECTION1_9F531CE4A9E24F2D900F87CE6A328876

Linked to this, how can I get the scale bar and text to be a fixed length but change the tick marks based on the scale with the items centered?

with settings as

I am using 3.22

Best Answer

You could try "predefined scale (best fit)" under Map Item properties.

Set the scales under Settings - Options - Map tools:

Related Solutions

QGIS – Subdividing Scale Bar Segments Using QGIS

There's a few steps involved:

Create your first scalebar showing kilometers and set the relevant options:

Select the first scalebar and copy/paste it below the original and set the relevant options:

For the copied scalebar, set its Font colour to have an opacity of 0%:
```
Item Properties > Fonts and colours > Font colour
```

Move the copied scalebar and align it to match the original scalebar. Select both these scalebars and group them:

You should hopefully have a scalebar with subdivided segments:

ArcGIS Data Driven Pages – How to Change Scale Bar Interval and Settings

I don't think you can change the properties of the scale bar using the out-of-the-box Data Driven Pages functionality.

However, that is not to say that what you're looking to do is impossible.

It wouldn't be terribly difficult to do this using ArcPy and is roughly described in this [ESRI Help Page][1]. Using their example, you could set up multiple scale bars, one for each setting you prefer, and then move them on and off the page based on scale of a given data-driven page.

To get it to work you would have to bypass the normal data-driven pages export and loop through the pages using Python and the above example.

Something along these lines (I HAVE NOT TESTED THIS, YOU WILL HAVE TO ADAPT IT TO YOUR DOCUMENT):

#You're going to need to reference your current map document and the data frame, assuming you just have one 
mxd = arcpy.mapping.MapDocument("CURRENT")
df = arcpy.mapping.ListDataFrames(mxd)[0]

#Associate scale bars in your layout with variables that arcpy can manipulate
m_scale = arcpy.mapping.ListLayoutElements(mxd, "MAPSURROUND_ELEMENT", "m scale bar")[0]
km_scale = arcpy.mapping.ListLayoutElements(mxd, "MAPSURROUND_ELEMENT", "km scale bar")[0]

#Iterate through all the pages, for each page, look at the scale, then adjust the scale bars to be on, or off, the page.
for page in range(1, mxd.dataDrivenPages.pageCount +1):

    #Check the scale and move the elements around to get the right scale bar on the page
    if df.scale < 25000:
        m_scale.elementPositionX = 5 #on the page
        km_scale.elementPostitionX = 15 #off the page

        #Export the current page to a pdf, using a specified path
        arcpy.mapping.ExportToPDF(mxd, r"C:\Project\Output\Project1.pdf", df)
    else:
        m_scale.elementPositionX = 15 #off the page
        km_scale.elementPostitionX = 5 #on the page

        #Export the current page to a pdf, using a specified path
        arcpy.mapping.ExportToPDF(mxd, r"C:\Project\Output\Project1.pdf", df)
    mxd.dataDrivenPages.refresh()

Best Answer

Related Solutions

QGIS – Subdividing Scale Bar Segments Using QGIS

ArcGIS Data Driven Pages – How to Change Scale Bar Interval and Settings

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