subtracting a number from string

how i can subtract a number from string ?

for example :

subject1_EO - i want to extract only number one..

[KSSV]

how i can subtract a number from string ? how?

Answer 1

[Star Strider]

One approach:

str = 'subject1_EO';
nrc = regexp(str, '\d+', 'match')
nr = str2double(nrc{:})

producing:

nrc =
  1×1 cell array
    {'1'}

nr =
     1

[Stephen23]

+1 a cunning use of a comma-separated list combined with the demand-driven output of nested functions. Explicit indexing is clearer though:

nr = str2double(nrc{1})

[Star Strider]

Thank you!

Answer 2

[Stephen23]

The most efficient solution by far (and simple too!):

>> str = 'subject1_EO';
>> val = sscanf(str,'subject%f')
val =  1