How to pad all numbers in array ?

How can I pad a vector of number with zeros ? I am able to do it with a for loop but I was wondering if there is a neater way to do it ?

For example,

a = [1 2 3 4 5];
b = sprintf('%06d',a);

gives me '000001000002000003000004000005'

I would like it to be [000001 000002 .....];

[Stephen23]

Floating point numeric values do not store explicit leading zeros. Even if you typed them, the zeros have no mathematical significance:

   >> [000001,000002]==[1,2]
  ans =
     1   1

Answer 1

[Stephen23]

 b = sprintf(' %06d',a{:});
              ^ add this space

[RuiQi]

its not giving me a cell of 1 row and 5 column it gives me c =

 000001 000002 000003 000004 000005.

Id like it to be b = 1 x 5 cell = [000001, 000002, 00003....] I thought its something like the comma separated lists but

b = [sprintf('%06d',a{:})]; also does not work

[Stephen23]

There is no simple way to create a cell array of strings, but this works:

 c = cellfun(@(n)sprintf('%06d',n),a,'UniformOutput',false)

Or you can read about the undocumented function sprintfc:

http://undocumentedmatlab.com/blog/sprintfc-undocumented-helper-function

[RuiQi]

wow sprintfc works very nicely. and i will also read through the cellfun

Answer 2

[Image Analyst]

What does that mean? If they're strings, fine -- you can have leading zeros. But if it's a number leading zeros are ignored, so printing or using 000003 will be just the same use using 3. So are you looking for a cell array? If so, see the FAQ: http://matlab.wikia.com/wiki/FAQ#What_is_a_cell_array.3F

[RuiQi]

Sorry it can be converted to a string. Id like to pad each element with zeros then store it in a cell. It can be of type string. I tried

a = {1 2 3 4 5};
b = sprintf('%06d',a{:});

but im still getting 000001000002.... even with %06c or %06s

[RuiQi]

training_set = cell(size(train,1),1);
for i=1:size(train,1)
training_set{i,1} = sprintf('%06d',train(i));
end

this works but im looking for a method without using the for loop if its possible

[RuiQi]

b = sprintf('%06d',[a{:}]);

doesnt work as well