Convert String to Numerical Matrix

Hi there,

Just wondering how to convert some matrix string (such as A = '[1,2,3,4,5]') into a numerical matrix (like [1,2,3,4,5]) so that it displays when entered into matlab like,

ans =

1 2 3 4 5

instead of

Columns 1 through 5

1.0000 2.0000 3.0000 4.0000 5.0000

Cheers,

Samuel

[Stephen23]

See also:

https://www.mathworks.com/matlabcentral/answers/357420-how-to-convert-a-numeric-string-into-a-numeric-range

Answer 1

[madhan ravi]

Normally str2num() is not suggested:

 Wanted = sscanf(A(2:end-1), '%d').' % edited after sir Walter’s comment to exclude []

[Walter Roberson]

The [] and comma interfere with sscanf unless you program for them

A = '[1,2,3,4,5]'; sscanf(A(2:end-1), '%d,')

[madhan ravi]

Ah, thank you sir Walter, I just typed straight away.

[Samuel Lee]

Thank you Madhan and Walter, this is cool. How do you adapt the code if there were no commas seperating the values? E.g. A = '[1 0.2 0.4 0.5 0.6]'

Cheers

[Walter Roberson]

A = '[1 0.2 0.4 0.5 0.6]'; sscanf(A(2:end-1), '%f')

ans = 5×1

1.0000 0.2000 0.4000 0.5000 0.6000

If the problem is that you might have commas or might not then:

A = '[1 0.2, 0.4, 0.5 0.6]'; sscanf(A(2:end-1), '%f%*[, ]')

ans = 5×1

1.0000 0.2000 0.4000 0.5000 0.6000

●

[Samuel Lee]

Cheers Walter, this is awesome. I couldn't quite work it out from the page (https://au.mathworks.com/help/matlab/ref/sscanf.html).

Thank you!

Answer 2

[Ameer Hamza]

See str2num(): https://www.mathworks.com/help/matlab/ref/str2num.html.

A = '[1,2,3,4,5]';
A = str2num(A);

Result

>> A
A =
     1     2     3     4     5

Another alternative which is generally not recommended, but can be useful here

A = '[1,2,3,4,5]';
A = eval(A);