22 replies to this topic

[maurice1979]

If anyone got url's for tutorials, tips, questions, ect.
I thougth it would be nice to put them here instead in the 'cp300 questions' that should handle more technical about the cp300

[maurice1979]

So I've got one.
I want to create a function but it's kinda complex to create just with 'define'
what I want to do is define a vector {a,b,c,d,....,n} it goes on -> calculate it's length en the sum of the lengths
the angle between the vectors.

using define I input this for length: define vlength(a,b,c,d,e,f) = sqrt(a^2+b^2+c^2+d^2+e^2+f^2)
UserC300, thank you for that tip.
but then I would have to type in vlength(1,2,0,0,0,0) , I just want to put any amount of numbers.
I think that would require more skill in programing.

[Andy.Davies]

couldnt you put it ina FOR loop? to repeatedly do the squareroot until it has done it for each variable/number

[BiTwhise]

didn't you read my post...

use a list as the argument to your function, that way you can have any size vector..

what I wrote:

alternatively you can define a function that takes any vector (as a list variable):

define len(v)=sum(v^2)^.5

for using it:

len({1,1,1})
(would give sqrt(3))

[UserC300]

BiTwhise is right, we already had that in the "CP300 Question-Topic".
By the way, why do you need to know the length of a more than 3-dim-Vector?

If someone is interested, I made an eActivity about "Vektoren":

eActivity Vektoren

[Overlord]

don't you never use more-than-3-dim vectors ?

[UserC300]

I did, but I can`t recall using or looking for the length of a 6-dim-or- something-vector as a number like |[2,4,7,1,3,4]|=9.75. That`s why I`m asking.

btw: at first, when I was just looking at your avatar(kinda scary) and not really reading your post, I misinterpreted it to:
Don`t you ever use 3-dim vectors! (no offence)

[maurice1979]

didn't you read my post...

define len(v)=sum(v^2)^.5

I did try define len(v)=sum(v^2)^.5
but instead of v I used x wich somehow didn't work, but I just tried out your method with a v and it worked like a charm

I need it for 5 or more dim vectors.
thnx a million

[BiTwhise]

No problem

[maurice1979]

I think I'm getting the hang of it, I was able to create a funtion to calculate the angle between 2 vectors,
but I want to learn more about programming, does anyone know some links??

[CrimsonCasio]

ask questions, I'll be happy to do a tutoring session with you

btw: what programming experiance do you have? (if any)

[maurice1979]

I am familiar with Macomedia's Director
Not that much, but still more than just a little

But with calculators none
your dealing with a dummie

[CrimsonCasio]

ok, lets go over a few core commands of basic:

{data} => {var}
the assignment opperator, takes the data and stores it in a variable, the data can be a string, number, list, or matrix (i think thats all).

1=>A //A now equals 1
"Hi"=>Str //Str contains the string "Hi"
{1,2,3}=>Array //Array now contains a 3 dimentionall list
[[0,0][0,0]]=>Mat //Mat contains a 2x2 matrix filled with 0's

= > < >= <=
these check to see if a condition is true or false, if its false the statement will evaluate to 0 if true it will be 1

lets do a quick program:

Lbl prgm //a Lbl is a marker that can be jumped to durring the program by using Goto {lbl name}
InputStr MyName,"Type in your name.","Your Name" // creates an input box that exepts a string, it ask the user for their name and stores it in MyName.
StrJoin "Hello ",name,txt //joins "Hello " and name and stores the result in txt
Print txt //outputs the text

try playing with that a bit, then I'll give you your next lesson

[BiTwhise]

Sorry for going back to this after such a long time..

Anyways, a note on the vector length function

If you use the built in vector functions, you probably have your vectors stored in "matrix" format, with '[' and ']' brackets, rather than the list format

To retreive the length of a vector in that format, you can take use of the built in dot product function. Hence the new len(v) function would be defined like this:

define len(v)=dotP(v,v)^.5

[maurice1979]

no I'm using the list format, but I saw that there is a resemblance between matrix- en list format in these calculations.
I created a function wich already excisted namely Crossp()
wich works better 'cause I weren't able to do this in list format.
with Crossp you can use 2 matrix vectors with list it's (1,2,3,4,5,6) instead of {1,2,3},{4,5,6}
It takes a lot of time to learn how to use your CP.

[BiTwhise]

I would recommend you take use of the built in functions to their fullest, that's eaiser.
If you work alot with vectors, you should switch over to the matrix format and get used to it asap. It makes it much easier to perform, for example, transformations, building arrays of vectors, etc.

[Overlord]

why don't use the norm function ? norm([5,9,1]) = norm of the vector (5,9,1)

[BiTwhise]

Because we are all retarded fools

Perhaps I should have a seccond look at that .. what was it called.. aye, manual

[Overlord]

you know today i opened and reread some sections of the manual... and i found commands like cross product, scalar product, conversion tu gauss-jordan matrix, ...

all what would have been useful for the past trimester to save time...

*feels like an idiot*

[maurice1979]

why don't use the norm function ? norm([5,9,1]) = norm of the vector (5,9,1)

Crossp = the norm of 2 vectors crossing

[Overlord]

the norm of 2 vectors crossing >> don't understand

[maurice1979]

I mean the normal

[Overlord]

yes but you must also know the direction of the vector and its length