Description

Formulaic is for anyone who uses equations - i.e. YOU - whether at work, study or play. Select an equation from the library, or easily create your own by typing in what you would write. Equations can be as simple as a conversion of units (e.g. from miles to kilometers), or involve multiple variables, nested subexpressions, etc.

Formulaic will not only evaluate your equation with the values you assign to variables, but it also includes a numerical solver that works backwards: You specify the result value of the equation; Formulaic determines the input value of any one variable used in the equation (but see limitations, below).

Consider the "Profit" equation in the "Business" section of the equation library, as shown in the application screenshots. In addition to computing profit based on the quantity, selling and cost prices you provide, Formulaic will also answer these questions: "How many units do I have to sell for a profit of 100?", or "What price do I have sell my widgets at, to make 5000 profit from 2752 units?". The same forward and backward computations can be applied in corporate finance (e.g. balance sheet ratios), engineering, product management, physics, or any other discipline; even daily life (e.g. "If I give a tip of 25, what percentage of the bill does that represent?"). We believe Formulaic is like a calculator on steroids :)

Features

• Numerically evaluate equations - from very simple to rather complex - based on input values you provide
• Numerically solve equations for any one input variable, such that the desired result value is achieved
• Get started quickly with a library of over 100 equations, including unit conversions, as well as business, mathematical and scientific equations
• Create you own equations in simple algebraic notation, with virtually no limit on number of variables or complexity of the equation
• Use any of the built-in functions in your own equations, such as sin(), acos(), log(), min(), sqrt(), and many more, as well as constants, such as PI

Limitations: The numeric solver has been tuned to work well with the equations in the library. Some equations are not easily (or not at all) solvable using a numerical approach. For example, 4 = x^2 + 20 does not have a "real" solution for x, and the Formulaic solver doesn't know about complex numbers.

What's New in Formulaic?

Formulaic 1.2

• Rename existing equations
• Email user equations (and if you’ve computed a solution, all variable values)
• Import equations sent by others (as above) using “click here” in Formulaic emails from others

Formulaic 2.0

• User equations get their own separate library, and can be grouped into custom categories
• Constants move to an editable library, so you can add your own

Formulaic 2.1

• Variable values can be input using expressions, e.g. you can type in "sqrt(PI / 2)", and Formulaic will set your variable to the computed result

Use

After launching Formulaic, start by exploring the existing equation library:

1. Select an equation of interest by tapping on its title. The starting window shows several sections, each with one or more equations.
2. The “Solve” window shows the equation you’re working with in the top section, and the variables in the lower section. You can tap the blue button to the right of the equation to look at it (or edit it if its one of yours).
3. In the “Solve” window, supply values to the variables by tapping in the input-field for each value in turn.
4. Once you have provided all input values, tap on the question mark in the line which you want to solve for. The top line is reserved for the value of the equation (in gray), and any other lines correspond to the variables in the expression.

Once you’re happy with using equations from the library, you can proceed to defining your own equations:

1. From the main Formulaic window, tap in the + button in the top right.
2. The “Solve” window appears with a sample equation to get you started.
3. Tap the blue button to the right of the equation to edit it to your liking.
4. Tap “Save”. If your equation could be interpreted, you’ll be back on the “Solve” page allowing you to exercise your own equation just like you would any in the library. If there was a problem with your equation, an error message will provide details. If you don’t want to save changes, tap “Cancel”.

You’ll notice that your equations are retained, as are the values of your variables. One useful insight is that Formulaic differentiates between “local” and “global” variables. Local variables start with a lowercase letter, and their values are visible only in the equation in which they are defined. Global variables (which start with an UpperCase Letter) are shared amongst all equations.

For additional details on creating your own equations, check out Formulaic Reference.

Quick Tips

• To rename a user equation, tap the action button in the top right corner of the “Solve” page, and select “Rename Equation” from the action sheet.
• To delete a user equation, swipe over its entry from left to right in the main “Formulaic” page. Tap on the red “Delete” button that appears.
• To email an equation, tap the action button in the top right corner of the “Solve” page, and select “Email Equation” from the action sheet. The iPhone’s Mail application will display a new email template, with the subject set to the name of your equation, and the message body showing your equation.
• For more information about using Formulaic, see the Formulaic Reference and Equation Library.