I need help preallocating array?

2 次查看(过去 30 天)
ME
ME 2015-4-12
编辑: pfb 2015-4-12
I need help making this array preallocated.
p = 10;
newArray = [];
array = [];
for i = 1:p
a= variable1;
b = variable2;
c = variable3;
d = variable4;
e = variable5;
array = [a,b,c,d,e]
newArray= [newArray array];
end

采纳的回答

pfb
pfb 2015-4-12
Look at the function "zeros".
array = zeros(1,5);
newArray = zeros(1,5*p);
and, in the loop
newArray((1+(i-1)*5):(i*5))=array;
This way all you need is allocated before the loop.
I assume that the assignments of a through e come from function that have a different value for different i's.
If they are the same, it's just a tiling problem. You need "repmat".
  5 个评论
ME
ME 2015-4-12
in my original loop the reason i have
myArray = [myArray array];
was so that in each iteration array in copied in new row.
pfb
pfb 2015-4-12
编辑:pfb 2015-4-12
not really in a new row.
In your code "array" is copied at the end of the row vector newArray. No new rows.
Use the semicolon operator to add new rows. You should have written
myArray = [myArray; array];
I think you should read some documentation.
Anyway, to allocate your matrix (not vector)
newArray = zeros(p,5);
Filling it, now is much simpler. This fills the ith row of newArray with the current values in array.
newArray(i,:) = array;
You should state your problem better. Apparently, what you needed was filling the rows of a matrix, all the time.
And perhaps take a look into the basics of matlab.

请先登录,再进行评论。

更多回答(0 个)

类别

Help CenterFile Exchange 中查找有关 Logical 的更多信息

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by