Last month I began a series of articles in an effort to explore some of the ways a microcomputer can be utilized in the practice of Landscape Architecture other than through Computer Assisted Design and Drafting (CADD). This month I thought it might be a good idea to delve into how to use the computer to handle some of the `’number crunching” chores all offices have to accomplish.

The most common method for generating estimates, invoices, or bills of material with a microcomputer is through the use of a software program called a “Spreadsheet.” These programs are to numbers related work, what the word processing program is to typing. Spreadsheet programs such as Lotus 123, SuperCalc3, Multiplan, and others have gained tremendous popularity in recent years as the need to prepare all kinds of numeric related documents has increased. The ease with which this type of information can be entered, modified, and printed is one of the major reasons Spreadsheets have become so widely used. Another benefit that these programs provide is the ability to easily do “What-if” analysis. For example, answering a client’s question about the difference in price for using concrete instead of asphalt would take less than a minute on a Spreadsheet.

It is when you examine the cell ?EUR??,,????'??D2?EUR??,,????'?? that the difference between this type of program and a word processing program becomes apparent.

All Spreadsheet programs are made up of a grid (intersecting rows and columns). Wherever a row intersects a column you have a cell. These cells can hold one of three items in them: 1. a number, 2. a text label, or 3. a formula. All cells have a unique address such as: B25, which would be the address for the cell in column “B” and row “25.” Generally, the rows are used for itemizing the information to be calculated and the columns are used for the grouping of like elements and calculations. Below is a simplified example of a spreadsheet segment:

As you can see, the cell “A 1 ” has the label “Plant List” in it and the cell “B1 ” has “Quantity” entered. These are labels, which is one type of information that a cell can hold. Cell “B2” has the number”17” and “C2” has “19.50” in it. These are examples of the second type of entry a cell can have, that of a number. It is when you examine the cell “D2” that the difference between this type of program and a word processing program becomes apparent. At first glance this cell looks simply as if the number “331.50” has been entered. In reality this cell has the formula “B2*C2” stored in it. This formula tells the computer to multiply the number found in “B2” times the number found in “C2” and display the result of that calculation. The cells “D3”, “D4”, and “D5” also have a similar formula adjusted for their respective row numbers. Cell “D7” has a different formula, this one says: add up all the numbers found in column “D”, rows 2 through 5. Depending on which Spreadsheet program in use, it might look something like: Sum(D2:D5). All of the numerical information in our sample Spreadsheet is now inter-related and if we change any of the entries in it, the entire Spreadsheet will re-calculate itself to reflect the changes.

Wow! If you followed me through all that, you deserve a medal. I almost got lost myself and I’m writing all this! As you can see Spreadsheets are not quite as easily understood as word processing, but I am also sure you can see the tremendous potential they offer for manipulating number related information. Actual Spreadsheet programs can have several hundred rows and columns, so the complexity possible is staggering. Most popular Spreadsheet programs can also produce graphs based on the numbers and relationships you set up in the program.

Next month we will venture forward into the un-charted depths of Data Base Management and its application to Landscape Architecture.