Vensim has a number of options for importing data. Data can be directly accessed from an active spreadsheet application and it can be imported from simple text files in .dat format and also from tab delimited and spreadsheet formats. Which format you choose to work with depends largely on the sources from which you will be collecting data. Independent of the data source, the following are worth remembering:
| • | For comparison, use the same name for data series and variables in the model. |
| • | For Data variables, use the name of the Data variable in the data file. |
| • | Data need not be equally spaced, or present at all time points. |
| • | There is no limit to the number of data series used or the number of data points in a data series. |
