Math Terms - Visually Described ?

bobbym · 2010-12-25 04:10:01

Hi;

I am not sure what you are asking.

SuperLynx · 2010-12-25 11:38:51

In post #195 the first 4x4 matrix how is that read in 3D ? See how you have sX diagonally what do the other columns represent ?

How did you get latex to create a space between each number in your matrix graphs ?

Do you know a page that list all the symbols used in a latex in that program so I understand ?

In post #177 you list a matrix with a,b,c,d,e,f (etc) those are just variables that you could enter in numbers, as you mentioned matrix use variables which can be replaced with the numbers aka they are a fill in the blank type system

bobbym · 2010-12-25 15:05:31

Hi

In post #195 the first 4x4 matrix how is that read in 3D ? See how you have sX diagonally what do the other columns represent ?

The sx is the scaling factor of the x coordinate, sy is the scaling factor of the y coordinate, sz is the scaling factor of the z coordinate.

Do you see on your gui where it says scaling? Do you see where you can enter a number for x,y,z? Supposing I enter 3 for the x, 13 for the y and 2 for the z.

Then S would look like this.

Okay, but I think the codecogs site is better. For more info on latex.

http://www.mathisfunforum.com/viewtopic.php?id=4397

http://www.artofproblemsolving.com/Wiki … X:Commands

http://www.artofproblemsolving.com/Wiki … eX:Symbols

SuperLynx · 2010-12-25 16:28:27

What does the other rows and columns in that example represent?

bobbym · 2010-12-25 16:30:48

Nothing, the S matrix is for scaling an object. That is all it does. Try that in your program if you know how to work it.

SuperLynx · 2010-12-25 17:05:07

What does the other empty parts of that matrix, represent they must represent something ?

bobbym · 2010-12-25 17:07:30

They are filled with zeroes so that they do not add anything to the vector they are going to work on. The 3 entries on the diagonal are what scales the x,y,z point.

SuperLynx · 2010-12-26 07:22:06

The 3 entries on the diagonal are what scales the x,y,z point.

If the three entries on the diagonal are what scales the x,y,z point what do the other empty areas on that matrix represent, because I have to practice with latex I'm going to write it out.

X - 0 sX 0
Y - 0 sY 0
Z - 0 sZ 0

What do the other zero represent ? As far as I know a matrix in this case has sub-matrices if the middle of a matrix represents the sY in geometry what do the other rows represent ?

bobbym · 2010-12-26 08:15:41

Hi SuperLynx;

Forget about sub matrices, they have nothing to do with what we are talking about. The scaling matrix S is not an object. It is not a collection of x,y,z coordinates. It only requires three boxes to be filled each one will multiply x,y,z by the appropriate amount.

The scaling matrix is the one on the left it scales the vector which represents the 3D point (3,4,5). It outputs a new vector with the new position of the point. The x coordinate is multiplied by 2, the y coordinate is multiplied by 3, the z coordinate is multiplied by 4,.
The new position of the point (6,12,20). That is a scaling , think of it as the line from the origin to (3,4,5) has been stretched to (6,12,20). Try this in your program to see it.

SuperLynx · 2010-12-26 08:41:44

I understand how a matrix to vector works. If a matrix is converted to the scale of a object that would be x,y,z, I'm sorta understanding.

In your example you have 2,3,4 for the scale X,Y,Z what if you put 2 in the last column what axis is that ?

bobbym · 2010-12-26 08:49:11

I have no idea matrix multiplication has rules. In order to multiply each coordinate by the scaling factor you input only those 3 boxes can have anything in them. The rest are zeros. If you only wanted to scale or stretch the y coordinate by a factor of 5, you would enter:

Notice only the y coordinate of the point in the vector has been changed. It has been multiplied by 5.

SuperLynx · 2010-12-26 12:05:15

I'm going to do some studying on matrix, but before I take some time for that since I'm struggling with matrices, are Arrays just as difficult ?

bobbym · 2010-12-26 19:19:15

Arrays are a container. They are used in programming. They are used to hold information. They are really quite simple . They are not a mathematical term.

SuperLynx · 2010-12-27 00:13:11

Can you give an example, so they appear easier hopefully for me to understand as I want to try them out, unless that is you'll maybe need to know the tools names with what I use ?

bobbym · 2010-12-27 00:22:44

What language do you speak?

SuperLynx · 2010-12-27 00:57:03

I just asked for a few examples of Arrays ? You know what I'll give you some Array terms and you tell me what they mean, sound good

bobbym · 2010-12-27 01:02:06

An array is a programming container or construct. It is used by computer languages to hold data for quick access. Each language that supports them has a different syntax for them. That is why I ask you, what language do you wnat to implement them in?

SuperLynx · 2010-12-27 01:34:56

JScript.
What do the following terms mean:

- Build Array
- Insert in Array
- Find in Array

bobbym · 2010-12-27 01:58:34

Where did you get those terms from? You create an array in JScript like this:

http://msdn.microsoft.com/en-us/library … 80%29.aspx

I do not remember a whole about it as I do not speak scripting languages. I would guess once you understand what an array is, the terms finding an element in an array or inserting an element in an array will be easier.

SuperLynx · 2010-12-27 02:44:28

Arrays are from programming, I remember reading that when I was and still am studying Javascript. Those terms are from the 3D program, I want to know how to create a simple array.

bobbym · 2010-12-27 06:13:42

Hi SuperLynx;

If you mean from that 3D program I have no idea. Creating them in JScript is described in that link I gave you. Try the examples on the page.

SuperLynx · 2010-12-27 09:01:45

I'm going to do some matrix and array studying, when I have question I'll update

bobbym · 2010-12-27 17:28:56

Hi SuperLynx;

That is good. Buzz me when you got a question and good luck!

SuperLynx · 2011-01-19 15:20:36

Update: I have figured out how you add / subtract / multiple matrices. I don't know how you divide matrices and how matrices are written, for example there is always a big letter outside of the brackets and smaller letters within the brackets.

Bobby you were or still am a programmer, maybe you can help me understand arrays. You know I'm working with a visual based math in my 3D program that is identical to MatLab.

bobbym · 2011-01-19 15:29:56

Hi SuperLynx;

I will do what I can but I must tell you I would not use Matlab or anything like it on a bet. 5 gigabyte programs make me want to format my hard drives with them on it. But arrays are a common data structure so please post your questions.

Also as a programmer I was a nutcase, I did not program top down ( I work bottom up ) goto less, object oriented or anything like it. I do not bulk up code with comments or 5k long variable names. I come from a time where you had to fit an entire program in 158 bytes. Todays boys from Redmond cannot program in less than 10 gigabytes. I do not like procedural languages but favor functional ones. Programming is an art not a skill that you teach someone. You do not crank out programmers like you are baking chocolate chip cookies.

Anyway, what the heck were we talking about?

Math Is Fun Forum

#201 2010-12-25 04:10:01

Re: Math Terms - Visually Described ?

#202 2010-12-25 11:38:51

Re: Math Terms - Visually Described ?

#203 2010-12-25 15:05:31

Re: Math Terms - Visually Described ?

#204 2010-12-25 16:28:27

Re: Math Terms - Visually Described ?

#205 2010-12-25 16:30:48

Re: Math Terms - Visually Described ?

#206 2010-12-25 17:05:07

Re: Math Terms - Visually Described ?

#207 2010-12-25 17:07:30

Re: Math Terms - Visually Described ?

#208 2010-12-26 07:22:06

Re: Math Terms - Visually Described ?

#209 2010-12-26 08:15:41

Re: Math Terms - Visually Described ?

#210 2010-12-26 08:41:44

Re: Math Terms - Visually Described ?

#211 2010-12-26 08:49:11

Re: Math Terms - Visually Described ?

#212 2010-12-26 12:05:15

Re: Math Terms - Visually Described ?

#213 2010-12-26 19:19:15

Re: Math Terms - Visually Described ?

#214 2010-12-27 00:13:11

Re: Math Terms - Visually Described ?

#215 2010-12-27 00:22:44

Re: Math Terms - Visually Described ?

#216 2010-12-27 00:57:03

Re: Math Terms - Visually Described ?

#217 2010-12-27 01:02:06

Re: Math Terms - Visually Described ?

#218 2010-12-27 01:34:56

Re: Math Terms - Visually Described ?

#219 2010-12-27 01:58:34

Re: Math Terms - Visually Described ?

#220 2010-12-27 02:44:28

Re: Math Terms - Visually Described ?

#221 2010-12-27 06:13:42

Re: Math Terms - Visually Described ?

#222 2010-12-27 09:01:45

Re: Math Terms - Visually Described ?

#223 2010-12-27 17:28:56

Re: Math Terms - Visually Described ?

#224 2011-01-19 15:20:36

Re: Math Terms - Visually Described ?

#225 2011-01-19 15:29:56

Re: Math Terms - Visually Described ?

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