Incrementally growing and adding to a matrix

Hello,

I'm new to matlab and am having a lot of trouble figuring out how to add elements to a matrix while simultaneously increasing the value of the existing elements.

For example, if my increment of change is .2, then i would want each number in my matrix to grow by .2 during each timestep. However, I also need to be making the matrix one element larger at each timestep.

t1 = .2 t2 = .4 .2 t3 = .6 .4 .2

I'm kind of at a loss, so any help would be greatly appreciated!
etc, etc.

Answer 1

[Jan]

t = [];
for i=1:100
  t = [t, 0] + 0.2;   % Or [t + 0.2, 0.2];
end

Another method:

for i = 1:100;
  t = (i:-1:1) * 0.2;
end

Be aware that a growing array is a very inefficient method. It is better to create the vector once and use indexing to operate on parts:

tFull = (100:-1:1) * 0.2;
for i = 1:100
  t = tFull(101-i:100);
end

Answer 2

[Sean de Wolski]

Don't do this!!

http://matlab.wikia.com/wiki/FAQ#How_can_I_create_variables_A1.2C_A2.2C....2CA10_in_a_loop.3F

t = 0.2:0.2:maxt

or; if you need what you have above

t = tril(toeplitz(0:.2:1));

t(3,:)

[Jan]

The FAQ concerns the formulation "t1=..., t2=...". As fas as I understand, the OP does not really want to create these different variables explicitely. If he does: Please follow Sean's link. +1

Answer 3

[Aryn]

I tried the first method and it worked. Luckily, I only have to go through 30 or 40 iterations. The second method might be a little complex for me at this point, but I will definitely look into it.

Thanks to both for the quick response!!!

[Sean de Wolski]

If you give us an idea of the bigger picture we can probably help you refine the global approach as well as just creating t.