MATLAB: How to use textscan to split a string containing numbers, NaN and strings with quotes (or not)

Question

Edit: the final purpose is to use textscan on a large file (~1gb), so processing the string before applying texscan is not possible.

This is the string I want to split with "textscan":

s = '-0.27,"NAN","NAN",0.6,"22/09/17 22:59"';

I have tried different syntax:

– test 1

textscan(s, '%f%f%f%f%s', 'delimiter', ',', 'CollectOutput', false, 'MultipleDelimsAsOne', 0, 'HeaderLines', 0, 'endOfLine', '\r\n', 'Whitespace', ' "')

Result: [-0.2700] [NaN] [NaN] [0.6000] {'22/09/17 22:59"'}

the best result, only problem: the left over quote at the end of the string. I don't understand why, are the chars listed in "Whitespace" not supposed to be removed?

– test 2

textscan(s, '%f%f%f%f%q', 'delimiter', ',', 'CollectOutput', false, 'MultipleDelimsAsOne', 0, 'HeaderLines', 0, 'endOfLine', '\r\n', 'Whitespace', ' "')

Result: [-0.2700] [NaN] [NaN] [0.6000] {'22/09/17 22:59"'}

same as above

– test 3

textscan(s, '%f%f%f%f%q', 'delimiter', ',', 'CollectOutput', false, 'MultipleDelimsAsOne', 0, 'HeaderLines', 0, 'endOfLine', '\r\n')

Result: [-0.2700] [0x1 double] [0x1 double] [0x1 double] {0x1 cell}

fail to read NANs

– test 4

textscan(s, '%f%f%f%f"%s"', 'delimiter', ',', 'CollectOutput', false, 'MultipleDelimsAsOne', 0, 'HeaderLines', 0, 'endOfLine', '\r\n', 'Whitespace', ' "')

Result: [-0.2700] [NaN] [NaN] [0.6000] {0x1 cell}

fail to read the string

– test 5

textscan(s, '%f%f%f%f"%s"', 'delimiter', ',', 'CollectOutput', false, 'MultipleDelimsAsOne', 0, 'HeaderLines', 0, 'endOfLine', '\r\n')

Result: [-0.2700] [0x1 double] [0x1 double] [0x1 double] {0x1 cell}

fail to read NANs

– test 6

textscan(s, '%f"%f""%f"%f"%s"', 'delimiter', ',', 'CollectOutput', false, 'MultipleDelimsAsOne', 0, 'HeaderLines', 0, 'endOfLine', '\r\n')

Result: [-0.2700] [NaN] [0x1 double] [0x1 double] {0x1 cell}

fail to read the 2nd NAN

– test 7

textscan(s, '%f"%f""%f"%f%q', 'delimiter', ',', 'CollectOutput', false, 'MultipleDelimsAsOne', 0, 'HeaderLines', 0, 'endOfLine', '\r\n', 'Whitespace', ' "')

Result: [-0.2700] [0x1 double] [0x1 double] [0x1 double] {0x1 cell}

fail to read NANs

Any suggestion? Thanks

Answer 1

textscan(s, '%f%f%f%f%q', 'delimiter', ',', 'treat','"NAN"')