topic Modelbuilder: Calculating value on added field in ModelBuilder Questions https://community.esri.com/t5/modelbuilder-questions/modelbuilder-calculating-value-on-added-field/m-p/811234#M135 <HTML><HEAD></HEAD><BODY><SPAN>I have a county level database of population statistics and am creating a model that will add a new field to the database, pop_density (population density). After adding the new field, I want the model to calculate the population density by dividing population by area. Both population and area already exist in my database. </SPAN><BR /><BR /><SPAN>I insert the Calculate Field tool and specify as the input for Calculate Field the output file from the Add Field tool. When I go to input the expression for pop_density in Calculate Field, it only shows me the Pop-Density field I just added, and it does not show me any of the pre-existing fields in my database. How do I use the Calculate Field tool when one of the variables in the calculation formula does not exist until the model has been run?</SPAN></BODY></HTML> Tue, 29 May 2012 20:29:41 GMT JohnWarden 2012-05-29T20:29:41Z Modelbuilder: Calculating value on added field https://community.esri.com/t5/modelbuilder-questions/modelbuilder-calculating-value-on-added-field/m-p/811234#M135 <HTML><HEAD></HEAD><BODY><SPAN>I have a county level database of population statistics and am creating a model that will add a new field to the database, pop_density (population density). After adding the new field, I want the model to calculate the population density by dividing population by area. Both population and area already exist in my database. </SPAN><BR /><BR /><SPAN>I insert the Calculate Field tool and specify as the input for Calculate Field the output file from the Add Field tool. When I go to input the expression for pop_density in Calculate Field, it only shows me the Pop-Density field I just added, and it does not show me any of the pre-existing fields in my database. How do I use the Calculate Field tool when one of the variables in the calculation formula does not exist until the model has been run?</SPAN></BODY></HTML> Tue, 29 May 2012 20:29:41 GMT https://community.esri.com/t5/modelbuilder-questions/modelbuilder-calculating-value-on-added-field/m-p/811234#M135 JohnWarden 2012-05-29T20:29:41Z Re: Modelbuilder: Calculating value on added field https://community.esri.com/t5/modelbuilder-questions/modelbuilder-calculating-value-on-added-field/m-p/811235#M136 <HTML><HEAD></HEAD><BODY><SPAN>Those fields should be there. First try saving and closing your model, them re-opening it. Next, check if you have done any previous operations that might have removed them, such as Buffer? If so, you may need to perform a join to get your original fields back.</SPAN></BODY></HTML> Tue, 29 May 2012 21:12:36 GMT https://community.esri.com/t5/modelbuilder-questions/modelbuilder-calculating-value-on-added-field/m-p/811235#M136 EadieKaltenbacher 2012-05-29T21:12:36Z