Mercurial > hg > octave-max
changeset 14096:153581342e47 stable
Always separate numeric fields by whitespace too; gracefully catch too wide literals & fixed width format conversion specifiers
author | Philip Nienhuis <prnienhuis@users.sf.net> |
---|---|
date | Thu, 22 Dec 2011 12:01:35 -0500 |
parents | 595ee644fa6f |
children | 4804ad4ce0de |
files | scripts/io/strread.m |
diffstat | 1 files changed, 115 insertions(+), 43 deletions(-) [+] |
line wrap: on
line diff
--- a/scripts/io/strread.m +++ b/scripts/io/strread.m @@ -1,4 +1,5 @@ ## Copyright (C) 2009-2011 Eric Chassande-Mottin, CNRS (France) +## Copyright (C) 2011 Philip Nienhuis ## ## This file is part of Octave. ## @@ -123,8 +124,10 @@ ## Any character in @var{value} will be used to split @var{str} into words ## (default value = any whitespace). ## -## @item "emptyvalue" -## Parts of the output where no word is available is filled with @var{value}. +## @item "emptyvalue": +## Value to return for empty numeric values in non-whitespace delimited data. +## The default is NaN. When the data type does not support NaN +## (int32 for example), then default is zero. ## ## @item "multipledelimsasone" ## Treat a series of consecutive delimiters, without whitespace in between, @@ -144,6 +147,8 @@ ## trimmed; the string defining whitespace must be enclosed in double ## quotes for proper processing of special characters like \t. ## The default value for whitespace = " \b\r\n\t" (note the space). +## Unless whitespace is set to '' (empty) AND at least one "%s" format +## conversion specifier is supplied, a space is always part of whitespace. ## ## @end table ## @@ -226,7 +231,7 @@ endswitch case "delimiter" delimiter_str = varargin{n+1}; - if (is_sq_string (delimiter_str)) + if (strcmp (typeinfo (delimiter_str), "sq_string")) delimiter_str = do_string_escapes (delimiter_str); endif case "emptyvalue" @@ -235,13 +240,13 @@ warning ('strread: property "expchars" is not implemented'); case "whitespace" white_spaces = varargin{n+1}; - if (is_sq_string (white_spaces)) + if (strcmp (typeinfo (white_spaces), "sq_string")) white_spaces = do_string_escapes (white_spaces); endif ## The following parameters are specific to textscan and textread case "endofline" eol_char = varargin{n+1}; - if (is_sq_string (eol_char)) + if (strcmp (typeinfo (eol_char), "sq_string")) eol_char = do_string_escapes (eol_char); endif case "returnonerror" @@ -329,8 +334,14 @@ endif if (! isempty (white_spaces)) - ## Remove any delimiter chars from white_spaces list - white_spaces = setdiff (white_spaces, delimiter_str); + ## For numeric fields, whitespace is always a delimiter, but not for text fields + if (isempty (strfind (format, "%s"))) + ## Add whitespace to delimiter set + delimiter_str = unique ([white_spaces delimiter_str]); + else + ## Remove any delimiter chars from white_spaces list + white_spaces = setdiff (white_spaces, delimiter_str); + endif endif if (isempty (delimiter_str)) delimiter_str = " "; @@ -344,27 +355,28 @@ pad_out = 0; ## Trim whitespace if needed - ## FIXME: This is very complicated. Can this be simplified with regexprep? if (! isempty (white_spaces)) ## Check if trailing "\n" might signal padding output arrays to equal size ## before it is trimmed away below if ((str(end) == 10) && (nargout > 1)) pad_out = 1; endif - ## Remove repeated white_space chars. First find white_space positions - idx = strchr (str, white_spaces); - ## Find repeated white_spaces - idx2 = ! (idx(2:end) - idx(1:end-1) - 1); - ## Set all whitespace chars to spaces - ## FIXME: this implies real spaces are always part of white_spaces - str(idx) = ' '; - ## Set all repeated white_space to \0 - str(idx(idx2)) = "\0"; - str = strsplit (str, "\0"); - ## Reconstruct trimmed str - str = cell2mat (str); - ## Remove leading & trailing space, but preserve delimiters. - str = strtrim (str); + ## Condense all repeated whitespace into one single space + ## FIXME: this will also fold repeated whitespace in a char field + rxp_wsp = sprintf ("[%s]+", white_spaces); + str = regexprep (str, rxp_wsp, ' '); + ## Remove possible leading space at string + if (str(1) == 32) + str = str(2:end); + endif + ## Check for single delimiter followed/preceded by whitespace + ## FIXME: Double strrep on str is enormously expensive of CPU time. + ## Can this be eliminated + if (! isempty (delimiter_str)) + dlmstr = setdiff (delimiter_str, " "); + rxp_dlmwsp = sprintf ("( [%s]|[%s] )", dlmstr, dlmstr); + str = regexprep (str, rxp_dlmwsp, delimiter_str(1)); + endif ## FIXME: Double strrep on str is enormously expensive of CPU time. ## Can this be eliminated ## Wipe leading and trailing whitespace on each line (it may be delimiter too) @@ -394,25 +406,31 @@ endfor endif - ## We now may have to cope with 3 cases: + ## fmt_words has been split properly now, but words{} has only been split on + ## delimiter positions. + ## As numeric fields can also be separated by whitespace, more splits may be + ## needed. + ## We also don't know the number of lines (as EndOfLine may have been set to + ## "" (empty) by the caller). + ## + ## We also may have to cope with 3 cases as far as literals go: ## A: Trailing literals (%f<literal>) w/o delimiter in between. ## B: Leading literals (<literal>%f) w/o delimiter in between. ## C. Skipping leftover parts of specified skip fields (%*N ) - ## fmt_words has been split properly now, but words{} has only been split on - ## delimiter positions. Some words columns may have to be split further. - ## We also don't know the number of lines (as EndOfLine may have been set to - ## "" (empty) by the caller). + ## Some words columns may have to be split further to fix these. ## Find indices and pointers to possible literals in fmt_words idf = cellfun ("isempty", strfind (fmt_words, "%")); ## Find indices and pointers to conversion specifiers with fixed width idg = ! cellfun ("isempty", regexp (fmt_words, '%\*?\d')); idy = find (idf | idg); + ## Find indices to numeric conversion specifiers + idn = ! cellfun ("isempty", regexp (fmt_words, "%[dnfu]")); ## If needed, split up columns in three steps: if (! isempty (idy)) ## Try-catch because complexity of strings to read can be infinite - #try + try ## 1. Assess "period" in the split-up words array ( < num_words_per_line). ## Could be done using EndOfLine but that prohibits EndOfLine = "" option. @@ -434,7 +452,13 @@ iwrdp += length (fmt_words{ii}); if (iwrdp > iwrdl) ## Parse error. Literal extends beyond delimiter (word boundary) - error ("strread: Literal '%s' (fmt spec # %d) does not match data", fmt_words{ii}, ii); + warning ("strread: literal '%s' (fmt spec # %d) does not match data", ... + fmt_words{ii}, ii); + ## Word assumed to be completely "used up". Next word + ++iwrd; iwrdp = 0; + if (ii < numel (fmt_words)) + iwrdl = length (words{iwrd}); + endif elseif (iwrdp == iwrdl) ## Word completely "used up". Next word ++iwrd; iwrdp = 0; @@ -449,8 +473,12 @@ iwrdp += floor ... (str2double (fmt_words{ii}(regexp(fmt_words{ii}, '\d') : end-1))); if (iwrdp > iwrdl) - ## Error. Field extends beyond word boundary. - error ("strread: Field width '%s' (fmt spec # %d) extends beyond word limit", fmt_words{ii}, ii); + ## Match error. Field extends beyond word boundary. + warning ... + ("strread: field width '%s' (fmt spec # %d) extends beyond actual word limit", ... + fmt_words{ii}, ii); + ## Assume word to be completely "used up". Next word + ++iwrd; iwrdp = 0; iwrdl = length (words{iwrd}); elseif (iwrdp == iwrdl) ## Word completely "used up". Next word ++iwrd; iwrdp = 0; iwrdl = length (words{iwrd}); @@ -556,8 +584,10 @@ else ## Conv. specifier. Peek if next fmt_word needs split from current column - if (ii < num_words_per_line && idf(ii+1)) - if (! isempty (strfind (words{icol, 1}, fmt_words{ii+1}))) + if (ii < num_words_per_line) + if (idf(ii+1) && (! isempty (strfind (words{icol, 1}, fmt_words{ii+1})))) + --icol; + elseif (idg(ii+1)) --icol; endif endif @@ -569,11 +599,11 @@ ## Done. Reshape words back into 1 long vector and strip padded empty words words = reshape (words, 1, numel (words))(1 : end-num_words_padded); - #catch - # warning ("strread: unable to parse text or file with given format string"); - # return; + catch + warning ("strread: unable to parse text or file with given format string"); + return; - #end_try_catch + end_try_catch endif ## For each specifier, process corresponding column @@ -678,15 +708,19 @@ mult_dlms_s1 = true; ## FIXME: Should re-implement strsplit() function here in order ## to avoid strrep on megabytes of data. - ## If \n is in sep collection we need to enclose it in spaces in text + ## If \n is in sep collection we need to enclose it in text ## to avoid it being included in consecutive delim series - text = strrep (text, eol_char, [" " eol_char " "]); + enchr = ' '; + ## However watch out if eol_char is also in delimiters + if (index (sep, eol_char)); enchr = char(255); endif + text = strrep (text, eol_char, [enchr eol_char enchr]); else mult_dlms_s1 = false; endif ## Split text string along delimiters out = strsplit (text, sep, mult_dlms_s1); + if (index (sep, eol_char)); out = strrep (out, char(255), ''); endif ## In case of trailing delimiter, strip stray last empty word if (!isempty (out) && any (sep == text(end))) out(end) = []; @@ -795,10 +829,10 @@ %!test %! # No delimiters at all besides EOL. Plain reading numbers & strings %! str = "Text1Text2Text\nText398Text4Text\nText57Text"; -%! c = textscan (str, "Text%dText%1sText"); -%! assert (c{1}, int32 ([1; 398; 57])); -%! assert (c{2}(1:2), {'2'; '4'}); -%! assert (isempty (c{2}{3}), true); +%! [a, b] = strread (str, "Text%dText%1sText"); +%! assert (a, int32 ([1; 398; 57])); +%! assert (b(1:2), {'2'; '4'}); +%! assert (isempty (b{3}), true); %% MultipleDelimsAsOne %!test @@ -810,9 +844,47 @@ %! assert (d', [15, 25, 35]); %% delimiter as sq_string and dq_string +%!test %! assert (strread ("1\n2\n3", "%d", "delimiter", "\n"), %! strread ("1\n2\n3", "%d", "delimiter", '\n')) %% whitespace as sq_string and dq_string +%!test %! assert (strread ("1\b2\r3\b4\t5", "%d", "whitespace", "\b\r\n\t"), %! strread ("1\b2\r3\b4\t5", "%d", "whitespace", '\b\r\n\t')) + +%!test +%! str = "0.31 0.86 0.94\n 0.60 0.72 0.87"; +%! fmt = "%f %f %f"; +%! args = {"delimiter", " ", "endofline", "\n", "whitespace", " "}; +%! [a, b, c] = strread (str, fmt, args {:}); +%! assert (a, [0.31; 0.60], 0.01) +%! assert (b, [0.86; 0.72], 0.01) +%! assert (c, [0.94; 0.87], 0.01) + +%!test +%! str = "0.31,0.86,0.94\n0.60,0.72,0.87"; +%! fmt = "%f %f %f"; +%! args = {"delimiter", ",", "endofline", "\n", "whitespace", " "}; +%! [a, b, c] = strread (str, fmt, args {:}); +%! assert (a, [0.31; 0.60], 0.01) +%! assert (b, [0.86; 0.72], 0.01) +%! assert (c, [0.94; 0.87], 0.01) + +%!test +%! str = "0.31 0.86 0.94\n 0.60 0.72 0.87"; +%! fmt = "%f %f %f"; +%! args = {"delimiter", ",", "endofline", "\n", "whitespace", " "}; +%! [a, b, c] = strread (str, fmt, args {:}); +%! assert (a, [0.31; 0.60], 0.01) +%! assert (b, [0.86; 0.72], 0.01) +%! assert (c, [0.94; 0.87], 0.01) + +%!test +%! str = "0.31, 0.86, 0.94\n 0.60, 0.72, 0.87"; +%! fmt = "%f %f %f"; +%! args = {"delimiter", ",", "endofline", "\n", "whitespace", " "}; +%! [a, b, c] = strread (str, fmt, args {:}); +%! assert (a, [0.31; 0.60], 0.01) +%! assert (b, [0.86; 0.72], 0.01) +%! assert (c, [0.94; 0.87], 0.01)