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Equation Manager
The Equation Manager tool allows users with an understanding of algebraic equations and agronomy to write their own equations for use within the Fertility Module. This user facing tool can be used to create custom "one off" or even more comprehensive ones given the desired recommendation output.
Opening Equation Manager and Creating Equation Folders
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Creating Equations
1. Within the Equation Manager tool, right click over any equation folder.  2. Select "Add Equ", from the menu that appears 3. Give the equation set a name and click "Add" Equation Manager Functions Once an equation folder and equation set have been created, the user can now access the equation functions. Clicking the printer icon will open a separate browser window and deliver "Equation Details" report. Clicking " Edit" will allow the equation to be viewed and edited. Clicking " View" will allow the equation to be viewed, but not edited. Clicking " Copy" will allow the equation to be copied and renamed. Clicking " Download" will deliver an xml file download of the equation logic within a compressed zip folder. Clicking " Upload" will allow an equation downloaded from the system to be re-uploaded (requires that it is within a compressed zip folder). The "Note" area retains input text. The "Active" check box allows for equations to be activated and deactivated. The "Save" button saves changes made. Defining Equations (Adding Elements and Commodities)Once an equation has been created, it can be edited to contain equation logic. Please Note: The following screen shots will show a simple example equation for reference. The equation logic shown is not intended to suggest an optimal equation setup. 1. Click the " Edit" link text (shown in the section above). 2. The "Define Equation" window opens, click " Rx Data Type" . 3. "Add Data Type" drop down appears, select a soil element that the equation will contain, then click the plus icon. 4. Repeat step 3 to add another soil element, or click "Commodity" from the tree area 5. Select a commodity from the drop down menu and then click the plus icon 6. Repeat step 5 to add another commodity, or move on by clicking the commodity added in step 5. 7. The logic window opens, see section "Logic Window Explained" below for window functionality explanations, then see "Defining Equations Continued" section below. |
Define Equation Window Explained
| Click the Pencil icon [1] to edit the commodity. Click the plain "X" icon [2] to delete the commodity from the equation. Click the green plus [3] symbol to add the Equation Input defined. Select the desired unit of measure[4] that the result should be in. The "Database Variable" [5] drop-down menu allows for the selection of a database nutrient variable. The "Select Unit" [6] drop down menus correspond with the Define Equation Inputs, and allow a selection of applicable unit of measure. The "Default Value" [7] drop down menus also correspond with the Define Equation Inputs, and allow for a default value to be substituted in the equation in cases where there are no values available within the sample layers. The "User Variable" [8] input creates a variable input within the Fertility module that the user will define at the time of Rx creation. Example: One of the most common User Variable input is Yield Goal, but it could potentially be anything that the user should define at the time of creation. If a "User Variable (Var)" is defined by the user as "Yield Goal" in bu/acre unit, with a default value of 200, the equation will load "200" as the user input value by default. The "Multi-Depth Layer" [9] drop-down menu allows for a default depth to be selected for sample sets that have multiple depths. The "Define Equation" [10] buttons allow for the functions of the equation to be selected. Please Note: Equations always start with an "IF statement, and a result for the IF statement. The "Save Equation" [11] button allows for the equation logic to be saved for use in Fertility. The "Clear Equation" [12] button clears away any of the logic defined. The "Test Equation" [13] button opens a window where example input variables can be provided and the system offers a mathematical result based on the equation logic. This allows the user to quickly determine if required elemental output is correct without having to test the equation in Fertility. |
Creating an Equation (continued)
| 1. Begin by creating Variables in the "Define Equation Inputs" [14] 2. Added Variables will display in the "Database Variables" [15] 3. Equations always start with an "IF" statement, Click "IF" [16] 4. Input an IF statement, for example "[P] <= 50" Please Note: Variables/Operators [17] can be added into your equation logic by right clicking inside the "IF" and "Result" boxes. 5. Click "Result" [18] inside the "IF" box. Please Note: Results are in elemental lbs/ac, and as such the amount of product will differ based on the purity/percentage of the specific product 6. Input a Result Statement, for example "((50 - [P]) + (0.30 * [Yield Goal]))" Please Note: Parenthesis denote Order of Operation, an equal number of left/right parenthesis must be in place for the equation logic to work 7. "ELSE IF" and "ELSE " statements may be added to an "IF" statement to catch cases that fall outside the original "IF" statement. a. ELSE IF = Use else if to specify a new argument to test, if the previous conditions are false. b. ELSE = Use else to specify an argument to be executed at the end of the Equation logic to clean up anything not defined in previous "ELSE IF" Statements.
8. Click " ELSE IF" [19] and enter the desired argument for example "[P] > 50 and [P] <= 60" 9. Click " Result" [20] inside the "IF" box and enter the desired result for example "20 " NOTICE: Before Testing the Equation use the "Save Equation" button to save your progress. If not saved and the equation logic is invalid upon testing all progress will be lost. |
