linspace

I want to create a vector which runs from 1 to 260 with increments of 360 between every whole number.

I can do this manually by: y=linspace(1,2,360); y1=linspace(2,3,360);... and so on.

By combining these I would have a vector which was 260*360=93600 long. However, there must be a easier way of doing this? preferably without a loop.

Answer 1

[the cyclist]

N = 260;
y = linspace(1,N,(N-1)*360+1);

[Richard]

many thanks, I have slightly modified your answer to account for duplicates:

n=261;

linspace(1,n,(n-1)*360);

[David Young]

So you don't want the increment to be 1/360?

[the cyclist]

The change that you made will mean that the "fenceposts" will NOT exactly land on the integers. They will be off by increments of 1/(360*260). The +1 in my code was necessary to get the alignment correct. I suggest you get a feel for how this works by using smaller numbers than 260 and 360.

[Richard]

I see what you mean, but the vector must be a length of 93600 as it is used to plot against another vector of that length.

[David Young]

So maybe you need

linspace(1+1/360, n, (n-1)*360)

or

linspace(1, n-1/360, n, (n-1)*360)

Using linspace(1,n,(n-1)*360) is incorrect if the spacing between the points is meant to be 1/360. (See my answer below and the cyclist's comment above.)

[Richard]

ok thanks for your help, worked great.

Answer 2

[David Young]

If you concatenate the vectors y, y1 etc. the integer elements will be repeats. That is, it will go [1 1.0028 ... 1.9972 2 2 2.0028 ... ] and likewise at 3, 4 etc. Is that what you want, or do you really want it to go [1 1.0028 ... 1.9972 2 2.0028 ...]?

Assuming you actually want a linear sequence all the way through, you can just use

yall = linspace(1, 260, 259*360+1);

My choice of the final argument makes the difference between successive entries equal to 1/360, which I think is what you mean by increments of 360 between each whole number. If you use 260*360 for N, this will not be the case.