Welp, I've finally decided to actually give this a shot. I've wanted to make a program derive equations that are fed into it.

I've gotten some functionality out of it...but I can only input in a certain format. I CANNOT have spaces in between terms and operators...

4x^2+2x+1 = OK
4x^2 + 2x + 1 != OK

I'm using Java for this, mainly because I don't know squat about Regular Expressions, which are used in .Net. The only language of .Net I know worth anything is VB, which I still don't feel comfortable with, since I learned it on my own, and relied on a lot of my VB6 knowledge.

Any suggestions on how to go about this...?

And yes I know there are better ways to implement these things, but this is a rough version, I started it yesterday.

PS: It works for any terms (with no negative or multi-term exponents) (using the power rule)

f(x) = x^n ----> f'(x) = nx^(n-1)

I don't have any other rules coded out yet.

Here's the source code if you wanna look at it. It's just one file for now, with a small main method for testing.

 Function.zip ( 1.73k ) Number of downloads: 10


This post has been edited by Locke37: 25 Sep, 2008 - 02:23 PM

Doesn't Java have any function to strip certain characters away? You can just get rid of the spaces.

I found this with Google. It says it can strip characters away, but I'm no Java expert, so you can take a look at it yourself:

http://www.java-tips.org/java-se-tips/java...m-a-string.html

I'm way outta my league with this...I know...

I can strip spaces and such, it's just that it's hard to get at individual terms the way I did it, and if you enter spaces...it can't get at the terms correctly, it adds a null term.

And dammit I lost that idea...

This post has been edited by Locke37: 25 Sep, 2008 - 02:06 PM

Here is a very simple little "eliminate spaces" script that I came up with.:



And here is another quicky:


Hope that comes into use and you can get it to work nicely with your project

Java Strings have a split method.
string.split("\\s");
Will return an array of strings that have been split around whitespace.

You can then iterate through the array and append all of the elements to another sting.

You're making this way too hard. This quick test seems fine:

That makes sense...duh

I R dum. Because that worked...can't believe I didn't think of that, it's so simple.

Thanks a lot by the way!

This post has been edited by Locke37: 26 Sep, 2008 - 07:53 AM

This might help you along the way.

Ok, new task. Figuring out how to do the quotient rule.

For those of you who don't know...

f(x) = a / b --> f'(x) = (ba' - ab') / (b^2)

And, this is a future task, but...any ideas on how to actually make the program figure out what method to use to derive the given term/equation?