creating numerical values from parts of a string read

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I have the following problem, I use the following to read in a string in a column in excel
[numerics,strings] = xlsread (filename,'spreadsheet name','Axx:Ayy')
filename is not in qoutes because it is read in from a user input using
filename = sprintf('filename',answer)
looking at the strings array I can see that the characters are read into the array
I need to extract part of the string and convert it into numerical values
the strings looks like 0(07/24/2014 10:39:10.21304) I need the last part of the string 10.21304
My approach was to first separate the string using command
strsplit(strings (2,1)) where strings (2,1)
is the location in the matrix of the strings; the error I can getting is that
First input must be a string.
So clearly I don't understand the issue - I tried the following
str1 = strings (2,1) and the output is '2 (07/24/2014 10:39:10.21304)'
Does the presence of the qoutation marks have anythings to do with the error ?
Any insight as to how to resolve the problem would be appreciated. I have google
several approaches and have not found anything that I can try. My first issue
resolving the error 'First input must be a string'
Regards, Philip

Accepted Answer

Ben11
Ben11 on 6 Aug 2014
If your strings are always of the same format, you can use regular expression to look for the colon followed by a number and followed by a dot, and then retrieve the numbers you want.
A = '0(07/24/2014 10:39:10.21304)'
ColonLocations = regexp(A,'\:\d*\.\d*','match')
which gives:
ColonLocations =
':10.21304'
Get rid of the colon:
ColonLocations{1}(1) = []
Convert to number:
ColonLocations = str2num(ColonLocations{1});
You can make this shorter by combining a few lines.
ColonLocations =
10.2130
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More Answers (1)

Evan
Evan on 6 Aug 2014
Edited: Evan on 6 Aug 2014
Another option, using a lookaround operator.
A = '0(07/24/2014 10:39:10.21304)'
s = regexp(A,'(?<=:)\d+\.\d+','match');
n = str2double(s);
See more here.
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