Blog | Formula Sheet

# Formula Database

June 5th, 2013

I have just launched the beginnings of a formula database for the website! You can find it here. The idea is to build up an extensive and authoritative collection of formulas, available for free to the whole web. While Wikipedia has done well so far as a means to search for formulas, the formulas typically lack titles, descriptions, and proper categorization. Building a formula database at formulasheet.com should help to alleviate some of these shortcomings. Creating a formula database is no small task, and will be very difficult to accomplish alone (hence my initial reliance on Wikipedia). If you would like to be involved in this project to create a free database of formulas, please contact me. You would be surprised how far sending me a few of your formulas or allowing me to use one of your existing lists in the database will go. I will double check over all of the formulas for validity before including them in the database.

Cheers,

- Tim

# Donate and Intro Video

May 15th, 2013

To offset some of the costs of running Formula Sheet, I have added a donation button at the bottom of the main page (also below). Formula Sheet is provided completely free of charge, but is not free to run. The cost of hosting it is higher than that of a typical website, because it is not just static content, but a full web application with LaTeX running in the background. As a result, it is necessary to host Formula Sheet on a 'virtual private server', which is essentially the same as renting a full computer in cyberspace. If you find Formula Sheet to be a valuable resource and would like to see it stay alive, please take 30 seconds and donate below using PayPal or credit card. Your donation will go a long way toward the monthly cost of hosting the website. Thank you very much!

After countless hours of content creation and editing, I have created a Formula Sheet intro video. I hope that this video will quickly acquaint new users with the features of the site, as well as show off some capabilities that experienced users may have missed. Check it out!

As always, if you have any suggestions, you can contact me. Cheers,

- Tim

# Calculators and Tour

March 12th, 2013

Hi again everyone. I recently introduced a feature which I think is really cool: calculators. You can now solve selected formulas right here on FormulaSheet! Simply enter the variables that you know, and our calculator will solve for the one that you are trying to find. Any constants required by the formula are provided, making it a breeze to use. Click here to try it out for Newton's law of universal gravitation. Just plug in whichever variables you know, and the calculator will do the rest. You may use scientific notation (e.g. by typing '5.9736E24' to denote 5.9736×1024). Calculators are only available for a limited, but growing, number of formulas. You can see all of them by navigating to the 'Browse' tab, and clicking 'See all' adjacent to 'Most popular formula calculators.', or by clicking here. Hover over the formula and click 'Calculate' to access the calculator.

In the image above I was solving for the force of gravity between the Earth and a human-sized mass at its surface. I input the variables I knew (the two masses and the distance) and the calculator output the force that I was looking for. I could just have easily entered any other three of the four variables and it would have solved for the unknown one. Give it a try!

On another topic, I have added a tour of FormulaSheet to better explain its features in an immersive way. Click 'Take a tour' on the front page or from the help menu to check it out and discover features you may have overlooked. That's it for now. Cheers.

- Tim

# New features and recent publicity

January 29th, 2013

I've been working hard on FormulaSheet over the past couple of months, adding some features that I'd always wanted to include but hadn't gotten around to. The best way to keep up to date on new features is through our Facebook page, which if you 'like' will keep you well informed of the latest and greatest additions. Below is a summary of the features that I've added over the past month, as well as links to some publicity we've received.

One of my favourite FormulaSheet features is the ability to copy-to-Word and forgo the clunky Microsoft Equation Editor interface. When I launched the site I was only able to offer copy-to-Word capabilities for the {equation}, {displaymath}, and {align} LaTeX environments. Recently, I expanded FormulaSheet's capabilities, and it is now possible to copy-to-Word for the {eqnarray} and {multline} environments.

Formula lists are the easiest and quickest way of collecting and organizing formulas on FormulaSheet. To make lists more useful I have added the ability to render them as .pdf or .tex files. This means that lists can quickly be printed without needing to create a formula sheet.

Shared lists and sheets have been made more accessible through the addition of a 'Browse' tab. You can now browse all of the publicly shared content, putting more information at your fingertips.

The search feature has also been upgraded. From the search bar, you can now search your own stuff (when logged in), public content, and Wikipedia. Names and tags are searched, providing results for formulas, lists, and sheets. Search suggestions have been improved, and should offer more relevant query ideas. I hope that you enjoy the improved search feature!

FormulaSheet has seen some publicity recently. Check out what people are writing about us on MakeUseOf and EduTechIntegration.

That's all for now. As usual I welcome any feedback and read each email and comment personally.

- Tim

# The first couple of months since launch and the latest developments

December 27th, 2012

As a FormulaSheet user, you get 200 formulas worth of storage by default. I feel that this should be enough for most users. If you need to store more than 200 formulas, you can now earn 200 additional formulas for every 4 users that you refer. To do this, simply copy and paste the link found in your 'Account Settings' in the gears menu in the top right of the site. The link has the form http://formulasheet.com/#su|yourusername. After your referred user is verified, you will receive credit for the referral. For now, you can use this method to expand your storage. In the future, I may offer a premium storage package, which would give you the possibility of storing up to 5,000 formulas for a small monthly fee.

I have set up a Facebook page to keep you, the users, in the loop, and to allow you to share the concept of the site easily with friends. Be sure to 'Like' the page, and you will be the first to know about new features!

Signing into FormulaSheet every time you would like to access your stuff is time consuming, so I have modified the site to let you stay signed in. This option is enabled by default, but can be disabled by unchecking 'Keep me signed in' in your 'Account Settings'. So sign in now, for the last time!

I am going to continue improving the site in the new year. Your feedback will be essential to this process, so if you have suggestions, or find bugs in the web application, do not hesitate to leave a comment below, contact me by email, or leave your feedback on our Facebook page. I wish you a happy new year!

- Tim

# A better way to manage formulas

November 3rd, 2012

Formulas are the most compact form of knowledge available, distilling complex concepts in mathematics, science, and physics. Why have computers and the web, while meeting almost all of the world's informational needs, failed so gravely with formulas?

TeX, a markup language that allows users to input equations, was released in 1978. Since then, not a lot has changed. Microsoft has made some poor attempts at developing an equation editor; anybody who has used either TeX or LaTeX and Microsoft Word equation editor can attest to the magnitude of Microsoft's failure. Online and desktop equation editors have tended to only solve part of the problem.

I have created FormulaSheet as an attempt to bring formula creation and management into the 21st century, as well as to introduce formula search. You be the judge, but in my opinion, I have at least partially succeeded. Below I will outline the site's features and give some insight into how they work.

## Formula search

Finding formulas on the web is pretty difficult. Since I couldn't create a database of formulas by myself, I leveraged one of the internet's greatest resources: Wikipedia. On Wikipedia, formulas are written in LaTeX and rendered on their servers. Using a script, FormulaSheet extracts the LaTeX markup from Wikipedia on the fly. It then presents it in a way that allows you to use it immediately: save the image, copy the LaTeX or MS Word 2007+ source, or render it differently. Search can be done from the search bar at the top of the site. I hope that this feature will save people time. For example, you might not mind typing out the Pythagorean theorem.

	$$a^2 + b^2 = c^2$$


But you might be less thrilled about typing out longer formulas, like this Navier-Stokes equation from fluid mechanics, which I just used the search function to copy and paste here within seconds.

	$$\rho \left(\frac{\partial u}{\partial t} + u \frac{\partial u}{\partial x} + v \frac{\partial u}{\partial y}+ w \frac{\partial u}{\partial z}\right) = -\frac{\partial p}{\partial x} + \mu \left(\frac{\partial^2 u}{\partial x^2} + \frac{\partial^2 u}{\partial y^2} + \frac{\partial^2 u}{\partial z^2}\right)+ \rho g_x$$


The copy-to-Word button, present for both formulas that you search and formulas that you create by yourself, means that you won't have to wrestle with Microsoft Equation Editor ever again!

If you're in a technical field and you already have TeX or LaTeX documents lying around, there's no need to retype your formulas in order to start taking advantage of FormulaSheet. Simply upload your .tex file and a script will extract all of your formulas enclosed in $...$, $$...$$, $...$, align, alignat, displaymath, eqnarray, equation, flalign, gather, multline, or split environments. File upload can be performed in the 'My Stuff' tab.

## Formula creation

Formulas are created using the LaTeX markup language. I have put a lot of effort into trying to make the best online LaTeX equation editor.

I have tried to include all of the available symbols and operators in LaTeX — if I have missed any, please let me know in the comments below. For users not familiar with LaTeX markup, this editor is a great place to start. Advanced users will appreciate the editor's ability to create formulas in several different LaTeX environments. Formulas are rendered in real time when the 'Render' tab is open, meaning that you get immediate feedback on how the formula looks. Registered FormulaSheet users can add meta data in the 'Info' tab, including a title, tags, and a description.

## Formula management

Keeping all of your formulas in one place means that you'll never have to remember which file holds the formula you're looking for. Just log into FormulaSheet and access it via 'My Stuff' in your preferred format. Formulas can be grouped into lists to keep them organized. Formulas can also be used, together with diagrams and text boxes, to create a formula sheet. I envision this feature being used by students, professors, teachers, and teaching assistants to prepare for tests and exams. Since lists and sheets can be shared, professors and teaching assistants can share them with their class. Sheets can be accessed online or printed in .pdf format.

## Sharing

Registered users may publicly share lists and sheets that they create. The list or the sheet that's useful for you might also be useful for your colleagues, classmates, students, or anyone using FormulaSheet. That's why I incorporated the option to share into FormulaSheet. A unique link to your list or sheet allows others to view it, like for videos on YouTube. You can continue to edit the list or sheet while it's shared, and you can always stop sharing it if you change your mind.

## Formula rendering

FormulaSheet renders formulas the instant they are typed, outputting them as .png images, .pdf files, or .tex files. You can change the formula's look with different fonts and sizes. You can make a formula fit into any slideshow presentation or graphic by choosing colours for the text and the background. For .png images, you can choose your preferred resolution.

I hope that FormulaSheet teaches you something, saves you some time, makes teaching or studying easier, or makes you more productive. Please leave your feedback, good or bad, as a comment below.

- Tim