Python Minimum or Maximum Values in ArcGIS
Let’s say you have 2 separate columns in an attribute table and you want to find the minimum or maximum values between these columns. This would require a bit of Python coding.
Let’s say your fields are set up as follows:
You can use the field calculator and minimum or maximum functions.
How to calculate minimum values using Python in ArcGIS
Right-click the empty field Min, and select “Field Calculator…”. Select the Python radio box. Use the following code:
FOR MINIMUM:
min([!Rank!, !Rank2!])After running the field calculator with the code above, the minimum values will be calculated in the “Min” field.
| Rank1 | Rank2 | Min |
|---|---|---|
| 8 | 3 | 3 |
| 7 | 164 | 7 |
| 7 | 98 | 7 |
| 8 | 17 | 8 |
How to calculate maximum values using Python in ArcGIS
Similarly, you can use the maximum function to attain the highest value from multiple fields.
FOR MAXIMUM:
max([!rank!, !rank2!])After running the field calculator with the Python code above, the “Max” field will have the maximum value from the “rank1” and “rank2” fields.
| Rank1 | Rank2 | Max |
|---|---|---|
| 8 | 3 | 8 |
| 7 | 164 | 164 |
| 7 | 98 | 98 |
| 8 | 17 | 17 |
Maximum or minimum values from multiple fields
Python has the flexibility to evaluate the minimum and maximum values from multiple fields. After the comma, you can add additional fields to calculate minimum or maximum values.
FOR MINIMUM:
min([!Rank!, !Rank2!, !Rank3!])
FOR MAXIMUM:
max([!Rank!, !Rank2!, !Rank3!])After running the Python code above, the minimum and maximum values will be evaluated for multiple fields.
More built-in functions
Python is a diverse programming language that can suit the needs of GIS users.
It has hundreds of functions readily available. This includes a lot of the “helpers” you can find in ArcGIS Pro.
Built-in functions can be found in the Python documentation found on the Python Docs page.
We also have a thorough list of GIS programming tutorials to help guide you. Finally, check out our guide on how to capitalize the first letters with Python.
Thank you for this!
Two quick questions: How can I get the name of the column from which the max (or min) value was obtained?
Second, I analyze a row and find the max value but then I want to find the min value to the right (later in time) of the max value, how can I limit my search to min values to the right of the max value?