## Monday, June 24, 2013

### Tips for Creating your Formula

Although formula creation is a simple process, typing your formula is the correct and the most efficient way is essential to make it work.

Here are a few tips :

1. When you use variables, try and make them of single character only. This ensures that all the variables are unique. For example, if you are looking to make the formula for speed, which is distance/time, you should write is as d/t
2. When you define a formula, it contains a number of variables. These variables are the values which the user is required to provide at the time of solving the formula. So, it is essential to let the user know which variable stands for which value. To ensure maximum user friendliness of your formula, enter a useful description.
3. Remember that the variables listed in the variables field should be absolutely the same as the variables used in the formula. For example, defining a formula as 'length*breadth' and then defining variables as 'l,b', will not work. Defining the formula as 'l*b' and defining the variables as 'l,b' or even 'b,l' will work.
4. A useful description must tell the user which variable stands for which value. For example, consider this description for the formula of speed, "Formula to Calculate speed. Here, d = distance and t = time".
5. Typing formulas on your computer is very different from writing them paper. On the computer, you will find that typing the formula is a bit more complicated, as it has to be understood by a computer and not a human. Using brackets and operators are important.
6. Remember that if you have to multiply two variables, d and t, then dt will not work. You have to type it as d*t. Even dXt will not work. You have to use the proper operator as the computer understands it.
7. You will find that when you have entered the formula and are checking it, it does not look very organized or legible as the formulas that are already there. This is because to look legible, the formula has to be parsed as MathML, which is not possible until the formula has been approved by a moderator. Once the formula has been approved, MathML parsing is enabled for the formula and then your formula starts to look good.

## Saturday, June 22, 2013

### I verified my formula, then why does it still not appear on the website?

The formula that you have newly created will only appear on the website when a moderator has verified it on his end.

Basically, at the time when you verify the formula, we intimate the moderator about this and then he/she goes ahead and checks the formula and allows it to go live on the website.

### What happens when I save a formula I just created and checked?

After you have correctly filled out the form for formula creation and have then checked that the formula is working, then the application will ask you whether you want to save it. Once you opt in to saving it, the website will send a verification link to your email id. You need to click on that link. Once you click, you will be taken to the verification page where the formula will be automatically verified.  Remember that I have put a dual verification in place. So after you have verified the formula, a moderator also has to verify it. Only after it has been verified by both you and the moderator, will this formula appear on the website.

### What are constants and how to use them?

Constants is the name that we have given to the  symbols or functions that we use in maths. Symbols like Pi, Squareroot, Power etc which are not just symbols but have a purpose or a value are listed here.

When you need to use any one these, hover your mouse on the button of the constant and a tip for using it will appear. When you click on the button, the symbol is appended to the end of the formula, as it is currently typed. Don't try and cut/paste this symbol to change its position, as this probably might not(or probably will) work.

### How to Create a New Formula?

Creating a new formula is one of the most interesting and important parts of this website. This is page through which a user can add his own formula to our storage and share it with other users from around the world.

Following is a brief overview of the process involved:

1. Click on the button 'CREATE A FORMULA' which leads you to the formula creation page.
2. The first field 'Enter the display name' requires you to enter your own name. This will be shared with other users, so you can choose it as per your choice, but whatever you choose, maintain the same in all the formulas that you create in the future. This will let other users appreciate your work better.
3. The second field 'Enter your email id' requires you to enter the email id that you can currently access. Immediately after you fill out the form for creating this formula, we send you a verification link on this email id, to confirm that you are a genuine user. An important point to note is that this id is not shared with the other users. Also, we intend to store this id with the formula to help in getting in touch with you in case we have any doubts regarding the formula.
4. The third field 'Enter the Formula Name' requires you to name your formula. If its an existing formula, enter the name accurately and if this formula is your own creation, then enter a name which can be easily recognized by other users.
5. The forth field 'Enter a short description' requires you to describe the formula briefly. This description should ideally contain information about the variables to be used or any other info about the working or need of the formula. This description is displayed to the users when they use your formula and thus it needs to be accurate and concise.
6. The fifth field 'Choose a category' requires you to choose a category to place your formula in. Choosing the right category is important to enable other users to easily find and use your formula.
7. The sixth field, 'Enter the complete formula' requires you to accurately and carefully enter the complete formula. This, needless to say, is the most important part of the process. The hardest aspect of this part is that we hardly ever type formulas so it is difficult to accurately type the formula here. You will find that the format for entering the formula is kept simple, but maybe you will require to try a few times before you get it to work.
8. The next part is not a field, but a set of constants. Constants is the name that we have given to the  symbols or functions that we use in maths. Symbols like Pi, Squareroot, Power etc which are not just symbols but have a purpose or a value are listed here. When you need to use any one these, hover your mouse on the button of the constant and a tip for using it will appear. When you click on the button, the symbol is appended to the end of the formula, as it is currently typed. Don't try and cut/paste this symbol to change its position, as this probably might not(or probably will) work.
9. The seventh field 'Enter all the variables' requires you to enter the variable names, as used in the formula. If there is more than one variable you need to enter the variables, separated only by a comma. Dont use space or full stop or anything else, as it will not work. A variable is the value which needs to be fed in by the user at the time of using the formula, so basically, you are specifying the values that the formula will need while being used. For eample: if you have a formula to find the area of a rectangle which is L*B, then you need the user to enter the values for L and B which using the formula. So, you will enter 'L,B' in this field(ignoring the single quotes).
10. The last field is the captcha verification, which is very commonly used to ensure genuine users. You just need to enter the text that you see in the box, into the field.

Once you have correctly filled out the form, you can click the submit button, after which, you will be taken to the next page where you will shown the formula you have entered and you can try out it out by entering values for variables. If, in case you have not entered the formula correctly, the solver will not be able to solve the formula and will tell you about it.

In such a case, go back, make some changes in the formula that you may think would make the formula work, submit again and try again. I have not been able to a build error detection into the solver yet, so the website that only tell you that the formula is not working but cannot tell the reason for this. You have to figure that out yourself.

When you have your formula working, you can go ahead and save it. This will send a verification link to your email id. You need to click on that link. Once you click, you will be taken to the verification page where the formula will be automatically verified.

Remember that I have put a dual verification in place. So after you have verified the formula, a moderator also has to verify it. Only after it has been verified by both you and the moderator, will this formula appear on the website.