Custom Calculations

Custom calcs is an optional plugin that can be used to calculate a complex manufacturing cost, using all sorts of interesting formulas.

See below an example screenshot for the "making of curtains" that would be used along side a chosen "material"  (fabric).

The customer is asked to choose a "pleat style" and "width" and "height" dimensions. 

These choices are saved in a "variable name", and those variables become available to the calculations thereafter. 

The pricing steps happen in order from top to bottom.  

Depending on the type of a step, it may lookup a value, calculate a value, or output a value to be visible to the customer. eg in this case we want the customer to know how much material is consumed.  If the material is unknown, we set a default minimum width of 900 for the unknown fabric roll. 

The pleat style is convered to 2 different multipliers. One is to determine how much more fabric will be consumed to generate the fullness of the pleat style. The other factor is to consider how much manufacturing/sewing effort will occur. 

Once we know the basic dimensions and factors, we can start to calculate the derived variables. 

The Drops required is output to the cart, so that the customer can consider if the pleat style or dimension has pushed them to an extra drop. Each extra drop consumes much more fabric. 

Once we know the material consumption, we can set the quantity of that item, assuming the fabric is in our cart already (and we have standard approaches to make that possible)

The total cost of manufacture can be used to generate a cost on top of the base unit price, or to override the unit price. In this case, we want the manufacturing priced from: $100. Therefore we are reseting the line item price to be the greater of the cost of manufacture, or 100.. Rather than adding the manufacture cost on top of the $100, which is possible depending on your scenerio.

We also set a special variable called "showCalcDebug". If this variable exists, and has a positive number assigned, then we will output a detailed table showing all the calcs, so that you can work through any debugging issues while you setup your perfect manufacturing product.

Lookup Data

There are several lookup approaches. 

Lookup Simple

Converts an answer from a known option list (eg a combo box, button set), into a value for use in calculations. It's very important that your lookup variable is named exactly the same as the equation variable. The result of the lookup will be saved as the "Save variable". Often lookups are used for multiplication factors. If you are using multiplication factors, consider setting the default value to 1, or something that will work if you accidently add options to your option list, but forget to set a multiplication factor. 

Lookup Table (Exact Match)

A lookup table needs 2 variables to check, and these are specified in the equation area separated by a comma. The first value finds a row based on the left column of the table. The second value is finds the desired column based on the value in the top row. It should be noted that the exact match search requires that the row or column values are found successfully, using an exact ext search. So it is possible to search for text... 

eg

Equation=RodStyle,RodSize   

Equation=B,12   

Result = 9

Lookup Table (Nearest Match)

This works very similar to the lookup table above, however, the variables specified are assumed to be numbers. 

The nearest search will find the column or row with an equal or lessor value. 

The assumption is that customer values will be "rounded up" to the nearest value.

eg

equation=height,width   

equation=190,2200 

result = 100

Pasting Tabular Lookup Data From Excel

Most often a customer might fetch their tabular data from excel. Take care with some data sources that formatting may create too much hidden code, and the table won't save properly. Tip: remove all formating from the table prior to pasting it. Or use the cleanup buttons on the toolbar to tidy up the table prior to saving. You can also copy and paste HTML tables from websites, or anything that produces a table in the pasting area.  

1. Open your spreadsheet
2. Select only the relevant table cells, ignoring headers. We only want the applicable data and lookup values. 
3. Remove cell formating
4. Copy those cells from spreadsheet.
5. Paste into the lookup data area in our CMS.
6. Use the cleanup buttons to remove styling.
7. Save the form. 

Understanding Calculations / Equations

The product price calculator runs a sequence of calculation steps. Each step evaluates one equation. Its answer can be saved as a new variable for later steps, or used to set a price or another product value.

The Calculator only evaluates the equation. The surrounding product system supplies values such as quantity, weight, height, width, depth, and answers saved by earlier steps.

A simple calculation sequence

1. Calculate volume with width * height * depth and save the answer as volume.
2. Calculate material cost with volume * material_rate and save the answer as material_cost.
3. Calculate the total with money(material_cost * quantity) and use the answer as the price.

Variable names are not case-sensitive. A missing or null variable is treated as blank text, or as zero when a number is required.

Writing equations

• Use ordinary decimal numbers, for example 12, 3.5, or 1.2e3.
• A leading dollar symbol is ignored on a number, so $55 is treated as 55. Currency symbols supplied with numeric variable values are also ignored.
• Use ASCII operator characters. For example, use * for multiplication and / for division.
• Use parentheses to control the order, for example (width + 10) * quantity.
• A value directly followed by parentheses implies multiplication, so 5(5) means 5 * 5. Using * is usually clearer.
• Separate function arguments with commas, for example max(width, height, depth).
• Put text inside single or double quotes, for example 'Large' or "Blue".
• Functions and variable names are not case-sensitive.
• The words true, yes, y, and t mean true. The words false, no, n, and f mean false.
• The constants pi and e are available.

Operators

Division results are rounded to five decimal places using normal half-up rounding. The money(value) function rounds a final monetary value to two decimal places.

Normal calculation order applies: parentheses first, then powers, unary signs and NOT, multiplication/division/remainder, addition/subtraction, comparisons, bitwise operators, AND, and OR. Use parentheses whenever the intended order may not be obvious.

Common numeric functions

Advanced numeric functions

Text functions

The legacy text functions length, strlen, charcount, textequals, textcontains, and textstartswith accept plain unquoted text. An argument matching a variable name uses that variable; otherwise it is treated as literal text. For example, TEXTEQUALS(OperatingSystem,Chain Driven) compares the variable OperatingSystem with the text Chain Driven.

Conditions and choices

HTML entity text

Text supplied by product content may contain HTML entities. The calculator decodes numeric entities and common named entities before using the text. An encoded character counts as one character, so length('£12') returns 3. Common supported names include &, <, >, ", ',  , ¢, £, ¥, €, ©, ®, ™, and °.

Decimal numeric entities such as A and hexadecimal numeric entities such as A are also supported. Unknown or incomplete entities are left unchanged.

Invalid equations

An invalid equation does not stop later calculation steps. It records an error message so the product system can display the problem. Depending on the result requested by the product system, an invalid equation produces false for a Boolean, zero for a number, Error for text, or no general result.

Useful product examples