iframe-proxy | Sunbelt Computer Software

Repository navigation

History

function [dims, isndarray, maxlevel, count] = nestbracket2dim(str, brackets, testndarray)

% [dims, isndarray, maxlevel, count] = nestbracket2dim(str,brackets)

% Extracting the dimension vector of a JSON string formatted array

% by analyzing the pairs of opening/closing bracket tokenss; this function

% only returns valid dimension information when the array is an N-D array

% authors:Qianqian Fang (q.fang <at> neu.edu)

% input:

% str: a string-formatted JSON array using square-brackets for enclosing

% elements and comma as separators between elements

% brackets: (optional), a string of length 2, with the first character

% being the opening token and the 2nd being the closing token.

% if not given, brackets is set to '[]' to find matching square-brackets;

% for example, '{}' looks for a matching closing curly-bracket in

% the string key(pos(startpos,:end))

% testndarray: (optional), 1 to test if the input string contains an

% ND array, i.e. with uniform element lengths (recursively)

% output:

% dims: the speculated dimension vector with the length matching the maximum

% depth of the embedded bracket pairs. When the input string encodes an

% N-D array, the dims vector contains all integers; however, returning

% an all-integer dims vector does not mean the array is

% rectangular. if testndarray is set to 1, dims returns isndarray

% isndarray: 1 to indicate the input string contains an ND array,

% otherwise, 0

% maxlevel: return the depth of the enclosed brackets in the string, i.e. the

% length of the dims vector.

% count: the relative depth from the level 0 - scanning from the left

% to right of the string, an opening token increases the level by 1

% and a closing token decreases the level by 1; a zero indicates

% the positions of a matching bracket of the same level.

% example:

% str='[[ [1,2,3], [4,2,1]], [ [10,1,0], [2,5,10]] ]'; % an N-D array

% [dim,dep]=nestbracket2dim(str)

% str='[[ [1,2,3], [4,2,1]], [ [10,1,0], [2,5]] ]'; % an invalid N-D array

% [dim,dep]=nestbracket2dim(str)

% license:

% BSD or GPL version 3, see LICENSE_{BSD,GPLv3}.txt files for details

% -- this function is part of JSONLab toolbox (http://neurojson.org/jsonlab)

if (nargin < 2)

brackets = '[]';

end

str = str(str == brackets(1) | str == brackets(2) | str == ',');

count = cumsum(str == brackets(1)) - cumsum(str == brackets(2));

isndarray = testuniform(count, max(count));

if (nargin > 2 && testndarray)

dims = isndarray;

return

end

maxlevel = max(count);

dims = histc(count, 1:maxlevel);

dims(1:end - 1) = dims(1:end - 1) * 0.5;

dims(2:end) = dims(2:end) ./ dims(1:end - 1);

dims = fliplr(dims);

function isndarray = testuniform(count, maxval)

isndarray = false;

if (length(count) > 2)

idx = find(count(2:end) == count(1), 1);

if (idx == length(count) - 2 && count(1) < maxval)

isndarray = testuniform(count(2:end - 1), maxval);

return

end

if (~isempty(idx) && mod(length(count) - 1, idx + 1) == 0)

count2d = reshape(count(1:end - 1), idx + 1, []);

if (all(diff(count2d') == 0))

isndarray = true;

end

Sunbelt Computer Software

PL/B Language Development and Support

Navigation Menu

Repository navigation

nestbracket2dim.m

nestbracket2dim.m

Sunbelt Computer Software

PL/B Language Development and Support

FilesExpand file tree

nestbracket2dim.m

Latest commit

History

nestbracket2dim.m

File metadata and controls