Custom Formulas

BinaryEarth

About this app

This powerful app lets you create your own custom formulas and then perform computations using them by prompting you for the input values.

This app is easy to use, but unlike simpler apps, multiple entered values can be fed into multiple formulas and multiple output values can be displayed. The output of one formula in a group can be fed into the next by using the same variable name.

Related formulas can be grouped into categories to make them easy to find. e.g. Maths formulas, Surveying formulas, Loan interest formulas etc.

The order of variables displayed to the user can be changed, as can the number of decimal digits of precision shown in the output fields.

Three example formulas are pre-installed with the app. In order of increasing complexity they are: slope percentage, compound interest, and point scale factor. There are also a growing number of formulas available to easily download directly in the app from a web sharing hub. Current categories include health, finance, and surveying.

A formula group can be exported or emailed, allowing you to share your creations with other users of the app.

The results from multiple computations using the same formula can be saved to a CSV file for later viewing in a spreadsheet. You can also choose to compute the sum of the formulas for a range of values of one of the input variables using the sigma button.

In addition to evaluating formulas, there is also a calculator tool and a linear equation solving tool on the main page menu.

You can view the online help here: https://www.binaryearth.net/CustomFormulasHelp/

Ratings and reviews

I was originally looking for a programming app when I found this one. I watched the video and this is above and beyond the functionality I was initially seeking! I would love to see more in depth documentation or a user manual. I received developer feedback on the usage of the 'if()' statement. Turns out I was not using it correctly. Update: The developer replied to my email with some excellent feedback and examples! Now 5 stars!

Its good but still needs tweeking. I like the app and it's functionality, the biggest issue I have is it keeps forcing every number I input and the outputs, into scientific notation, including constants I put into formulas, which isn't an issue if that's what you want. But I don't always like using SN, because sometimes I just need to see my actual numbers without having to do the extra rearrangement in my head, especially if I'm a bit tired. Needs an option to fully disable SN.

Excellent app, but, what would make it even better would be the app database saved somewhere that doesn't need root to play around with. I find it easier to edit the database on the PC. That way I also have a backup copy. Any chance this could be done?

What's new

9.1: Allow entry of formulas in Linear Solver without having to insert *'s between coefficient and variable name.
9.0: Updated calculator tool.
8.9: Updated to target Android SDK 34.
8.8: Updated to target Android SDK 33.
8.7: Bug fix.
8.6: Added min(), max(), and avg() functions which each take two values.
8.5: Added an option under the "Copy database" button on the "About" dialog to restore the internal database from a copy in the app folder.