If statements

When you want a variable to have different values or formulas based on a condition, you can use if-statements. They always have to follow the structure if condition then X else Y

You can link multiple conditions with and and/or or:

• if condition1 or condition2 then value1 else value2
• if condition1 and condition2 then value1 else value2

You can also link conditions with a list using the syntax IN, for example:

• if month in [11, 12, 1, 2] then 90% else 100% -> means if the month is Nov, Dec, Jan or Feb, return 90% else return 100%.
• You can also use categories / category items in if-statements, see Category Items in formulas for more.

You can also link conditions with the exclusion of a list using the syntax NOT IN, for example:

• if month not in [11, 12, 1, 2] then 90% else 100% -> means if the month isn't Nov, Dec, Jan or Feb, return 90%, if it is return 100%.

You can have multiple layers of if statements too, for example:

• if condition1 then value 1 else if condition2 then value2 else [...]
• You can break each of these layers out onto separate lines of your formula editor using shift + enter
• Note that every if statement must have an else, otherwise Causal will return an error.

Examples of if statements:

• if timestep > 4 then 1 else 0
• if variable1 > variable2 then 100 else 200
• if timestep > 4 and timestep < 10 then 1 else 0
• if variable1 < 10 then 100 else if variable1 < 20 then 200 else 300