# International Futures Help System

## Computations Systematically (Algebraic Computations)

To access Computations, open Self-Managed Full Variable/Parameter Display.

Click on Computations. A new window will appear. In the box, type in a formula you would like IFs to calculate. For our example, we know that we have the percent of literate people in each country and the absolute number of people in each country, so we simply need to multiply the percentage of literate people with the total population. Our formula will be a*b (or any other letter). Use standard symbols in order to distinguish different mathematical functions. Use * for multiplication, / for division, + for addition, - for subtraction, () to group terms etc. After typing in this formula, click Enter. This will bring up a new window. From this window, you can accomplish the following:

Formula Name, Dimensions Name, Units Name: These three naming options are available but only the Formula Name is required. The Dimensions Name could be used to describe, for example, the geographic bounds of your formula. The Units Name could be used to describe the units being displayed in your formula (thousands of US\$).

After you have typed in the names you prefer, click Enter. This will bring you back to the Type your Formula window, also known as the Computations window.

The variables you used in your formula are now displayed in lower half of the Computations window in the left column: Now, click on Select Vars or on the variable. You will return to the Full Variable/Parameter Selection window where you will select a variable. For our example, we have two variables. For the first variable, we would like to select the LIT.

After you have selected the LIT variable, you will be asked to choose a geographic location. For our example, make sure country/region is selected and choose ALL. After choosing your first variable, you will return to the Computations window. From there, chose your second variable, which will return you to the Full Variable/Parameter Selection window. From there, choose the POP variable for ALL counties/regions. Now, your formula of variables will be displayed in the Display Box.

Click on Display and choose a Line Graph. You can now display the absolute population in each country that is literate, a variable that is not directly available for display in IFs, but that is available after creating a formula of variables.

Save Formula in Analog Option: Click on this option to save your formula. This will bring up a warning that, if you want to firmly save changes, you will have to manually copy IFsVar.MDB from the local driver to the Data directory after exiting IFs.

Display Formula: Select this option to display the formula currently used.