MATLAB: Convert a single char array to a vector of doubles with a non-whitespace delimiter [R2017b, Windows7]

sscanfstr2doublestr2num

Hi,

I have a binary file that when I load up into Matlab produces the following cell which contains a cell array called data:

1x1 cell array:
{'44.565,433.4544,34.332'}

This can be a very long list of numbers and I would like to avoid using str2num (which works fine). I have tried using:

slope = sprintf('%s,',data{:})
doubleArray = sscanf(slope, '%f')

This only give me the first number. I suspect this is because I have a ',' as a delimiter and not a whitespace character.

str2double(data)

returns a NaN and I suspect this is because I have a single char array in a cell and not an array of strings.

Any advice as to how to do this without str2num?

Cheers, TJ

Best Answer

a={'44.565,433.4544,34.332'};
str=a{1}(:);
strNum=str2double(strsplit(str.',','))

Thanks to Stephen Cobeldick, another and faster approach:

sscanf(a{1}, '%f,')

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MATLAB: Does STRMATCH in MATLAB cause an error for a cell array containing a numeric value

In this example:

str = 9;
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ind = strmatch(str,strs);

the normal STRMATCH is used, since the first input is not a cell array. In this case, 9 could be used as an ASCII value, and converted to a tab character. That character can then be compared with the other strings.

In this example:

str ={9};
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@CELL/STRMATCH will be used, since the first input is a cell array. In this case, the code checks that the cell array contains strings, and converts it to a char array:

if iscellstr(str), str = char(str); end

Cell arrays of strings are special cases of cell arrays, which are commonly used to store strings together which have different lengths, and there are many instances where cell arrays of strings and strings can be used interchangeably. However, {9} is not a cell array of strings, so it is not converted to a character array, which leads to the error being thrown by this code:

if ~ischar(str) | ~ischar(strs)
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You could use a regular expression. Assuming all the numbers you want to extract are integer:

str = 'c={ 4 of 5 stars, 5 of 5 stars, 5 of 5 stars, 3 of 5 stars, 3 of 5 stars, 4 of 5 stars}';
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