Quick matlab question

  • MATLAB
  • Thread starter elbarto
  • Start date
  • #1
33
0

Main Question or Discussion Point

Homework Statement


Hi,
Just wondering if someone could please steer me in the right dirrection for the correct syntax in matlab. I am trying to create a variable from an array of numbers and combine it with the letter k, to give me k1=[] k2=[] k3=[] etc. where [] is a 3x3 matracie




Homework Equations





The Attempt at a Solution



This isn't the problem I am working on but the solution to this would be a great help.

a=[1 3];
['k' int2str(a(2))]=[0 1 2;1 2 3;0 1 2]
??? Error: An array for multiple LHS assignment cannot contain character string.



Trying to get this

k3 =

0 1 2
1 2 3
0 1 2


Thanks
Elbarto

Homework Statement





Homework Equations





The Attempt at a Solution

 

Answers and Replies

  • #2
chroot
Staff Emeritus
Science Advisor
Gold Member
10,226
34
Use sprintf and eval.

- Warren
 
  • #3
33
0
Thanks for the reply, I did get the function to work, but I did read on the net that this was a long winded way of going through the process. does matlab have any operations to make this simpler?
 
  • #4
33
0
Just one more question regarding matlab, I am having trouble working with angles. I think sin(alpha) needs to be -1 {or I might just be haveing a realy bad day with my maths}. Either way, can someone please explain what I need to do to get pi() instead of 0. I wrote a program the works off inputted co-odinates and it is not operating like it should for horrizontal member.
consider moveing from point (0,0) to (-1,0)

>> dx=-1-0

dx =

-1

>> dy=0- 0

dy =

0

>> alpha=atan(dy/dx)

alpha =

0

>> sin(alpha)

ans =

0

For the rest of my program to work, I need to be able to evaluate sin properly otherwise the output is useless.

This is probably an easy question and the solution might be quite obvious but with my limited experience I haven't managed to think of anything yet.

Thank You
Regards Elbarto
 
  • #5
D H
Staff Emeritus
Science Advisor
Insights Author
15,393
682
Use atan2 instead of atan.
 
  • #6
33
0
Thanks allot for the reply. Works a treat, just what I was looking for.

Regards Elbarto
 

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