How to sort a structure by numbers in one of its fields?

First of all, I have used a workaround to label my structure fields as distances as the following:

    RX.(['d',num2str(distance{1})])(:,1) = data(:,45);  % COTS 1, X-axis
    RX.(['d',num2str(distance{1})])(:,2) = data(:,46);  % COTS 1, Y-axis
    etc.

so that my structure in the end looks like this:

      d0: [600000x6 double]
    d100: [525000x6 double]
     d10: [550000x6 double]
     d20: [475000x6 double]
      d2: [550000x6 double]
     d30: [450000x6 double]
     d40: [525000x6 double]
      d4: [600000x6 double]
     d50: [525000x6 double]
     etc.

I would like to be able to sort the fields in the structure so that they'd end up as

     d0: [600000x6 double]
     d2: [550000x6 double]
     d4: [600000x6 double]
     d6: [600000x6 double]
     d8: [600000x6 double]
    d10: [600000x6 double]
    d20: [600000x6 double]
    etc.

I can get as far as

RXnames = fieldnames(RX);
    for j = 1:length(RXnames)
        RXd(j) = regexpi(RXnames{j},'d(\d\d*)','tokens');
        RXd(j) = RXd{j};
    end
RXd = RXd';

which gives me the distances in a string array:

    '0'
    '100'
    '10'
    '20'
    '2'
    '30'
    '40'
    '4'
    '50'
    '60'
    '6'
    '70'
    '80'
    '8'
    '90'

and then I can str2double them to a number array which I can then sort, but then I lose association with the fields. Does anyone know of a way to sort the way I'm describing?

Thanks to anyone in advance!

Scott

Answer 1

[Andrei Bobrov]

eg

a = struct('d100',randi(125,4,5),'d458',3,'d7',rand(3),'d0','sd456'); % your data

p1 = regexp(fieldnames(a),'\d*','match');
[i1,i1] = sort(str2double(cat(1,p1{:})));
out = orderfields(a,i1)

[Scott Rauscher]

Ah, perfect. There's some smart people on here...

Thank you

Answer 2

[Azzi Abdelmalek]

s=fieldnames(x)
c=char(s)
s1=cellfun(@(x) (regexp(x,'\d+','match')),s,'un',0)
s2=cellfun(@str2double,s1)
[s3,idx]=sort(s2)
for k=1:numel(s2)
  b.(['d' num2str(s3(k))])=x.(strtrim(c(idx(k),:)))
end
x=b

[Scott Rauscher]

This worked perfectly, but the one right above you took less lines of code. Thank you though!!

Answer 3

[Milos]

You will have to pad field names with zeros:

d000
d005
d010
d077
d100

and then you can sort the fields using function:

orderfields