Symbology for specific values

Question

I want to apply a symbology scheme for the final layer of my model. Rules are -

All negative - Symbol A
0 - Symbol B
All positive symbol C
unknown - symbol D

I am not sure how I can define these intervals under Classification of Layer Properties. The minimum and maximum can vary since it will be used in a model. I tried to define manually (among other options - defined, standard deviation...etc.) but it worked only for that sample and failed for another example. I am using 'Apply Symbology from Layer' to display the model output finally.

Thanks

Answer 1

Finished with a categorical variable: I created another field to store values for this elevation difference (if ele_diff is less than 0 then ele_rank is -1...etc.). So now have only 4 unique values in the new column. It may not be the best solution but closing with it for now.

EDITED FOR CLARITY

Apparently @user8732 is reclassifying one column into 4 categories. This can be done using some python inside of field calculator.

Pre-Logic Script Code:

def check_ele(in_column):
    if in_column < 0:
        return -1
    elif in_column == 0:
        return 0
    elif in column > 0:
        return 1
    else:
        return None  # or some unique value... using None would retain the 'unknown' understanding of elevation presented in the question

FieldName =

check_ele(!ele_diff!)