How to reclassify a raster to show values greater than or equal to 56 in range of 1:139 in ArcMap?

[SangamAdhikari]

 

Hi spatial thinkers! I need some help with the question. How do I reclassify the CostRegion raster according to Step 9? Please guide me through this. The result would look like the last image.

[ChristopherCounsell]

The reclassify tool takes the input values and changes them.

https://desktop.arcgis.com/en/arcmap/latest/tools/spatial-analyst-toolbox/reclassify.htm

In your screenshot you can change the entries for old/new values to what you desire. e.g. you could reclassify values:

• 0-56 = 0
• 56 - 137 = 1

The output would be a raster with two values, 0 or 1. A 0 values indicates that the cell value is under 56 and a 1 value indicates it is higher (with 137 just being the highest value of the input raster).

Having a 0 or a 1 value makes it easier to do further analysis. E.g. multicriteria analysis would exclude sites that don't meet the criteria - excluding 0 - but could also weight sites, like giving values of 2 for those with scores over 100.

Your 'result' image has 4 output values. So it doesn't look like they've changed the values. They've just removed the value ranges below 56. 

A solution is in the geoprocessing tool, delete the entries 1-10, 10-27, 27-41, 41-56. This will give you a raster with four output range values above 56.

If this is exactly correct, had to say without the full procedure, but you should be able to navigate it now with the above understanding. 

[SangamAdhikari]

Thanks, Christopher. I tried but that didn't work. I can't get the desired layer. Maybe I'm wrong in earlier processes.

[ChristopherCounsell]

Maybe. Looking at your image, that's a lot of black. All values are 1?

Apply coloured symbology to your raster you are trying to reclassify. You
should be able to visualise it before the reclassify. You can symbolise the
ranges.

I'd walk through the steps again and check your raster outputs at each
step. Good luck!

[SangamAdhikari]

Steps 3 to 7 look like this. And Step 1 is creating a slope from DEM. Step 2 is creating a cost distance surface from the road and slope.

11 is the true value in step 5, right? 

My layers look like this in TOC.

I feel like I'm doing things correctly but I can't get to the final result.

[SangamAdhikari]

Would you mind if I ask for more help on this?

[ChristopherCounsell]

Did you mark the false data (12, 21, 22) as NoData? It looks like your input for question 9 is a value of 1 and fully contiguous.

[SangamAdhikari]

Yes, I did. 

This is what I was told.

W

Where should I put NoData in here?

Maybe my calculation for step 8 is wrong??