Editing a cell array.

I have a cell array

1ms 1kA 10V

2ms 2.2kA 3V

3ms 3.6kA 5.4V

I want to remove 'ms', 'kA' & 'V' from the cell array and then convert it into a matlab matrix with numerical value for further calculations.

[KSSV]

Read about regexp

Answer 1

[madhan ravi]

C={'1ms'  '1kA'     '10V'
   '2ms'  '2.2kA'   '3V' 
   '3ms'  '3.6kA'   '5.4V'};

Matrix=str2double(cellfun(@(x)regexp(x,'^(\d{0,5}\.{0,1}\d{0,5})','match'),C))

[Stephen23]

Note that regexp accepts a cell array of character vectors, so the cellfun call is totally superfluous. I recommend using the option 'once' to simplify the output handling.

Some notes about the regular expression itself:

\d{0,5}

why limited to just five digits?

\.{0,1}

is simpler as

\.?

The grouping parentheses are not required.

[madhan ravi]

Agree with Stephen:

Matrix=cellfun(@str2double,regexp(C,'^(\d*\.?\d*)','match'))
% or
Matrix=str2double(regexp(C,'^(\d*\.?\d*)','match','once'))

Gives:

Matrix =

    1.0000    1.0000   10.0000
    2.0000    2.2000    3.0000
    3.0000    3.6000    5.4000

Answer 2

[Stephen23]

To get the actual numeric values taking into account the SI prefixes you can use my FEX submission sip2num, which can be downloaded from FEX:

https://www.mathworks.com/matlabcentral/fileexchange/53886-scientific-prefix-to-number

>> C = {'1ms','1kA','10V';'2ms','2.2kA','3V';'3ms','3.6kA','5.4V'}
C = 
    '1ms'    '1kA'      '10V' 
    '2ms'    '2.2kA'    '3V'  
    '3ms'    '3.6kA'    '5.4V'
>> N = cellfun(@sip2num,C)
N =
        0.001         1000           10
        0.002         2200            3
        0.003         3600          5.4